Merge branch 'maint'

18 files changed, 4173 insertions, 3801 deletions

diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index bc42b75c7a..b7669b760b 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -1,5 +1,11 @@
 <?xml version="1.0" encoding="latin1" ?>
 <!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY make_ref
+  '<seealso marker="erts:erlang#make_ref-0">erlang:make_ref/0</seealso>'>
+  <!ENTITY transport_module
+  '<seealso marker="diameter_transport">transport module</seealso>'>
+  <!ENTITY dictionary
+  '<seealso marker="diameter_dict">dictionary</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -50,7 +56,7 @@ under the License.
 <p>
 This module provides the interface with which a user can
 implement a Diameter node that sends and receives messages using the
-Diameter protocol as defined in RFC 3588.</p>
+Diameter protocol as defined in &the_rfc;.</p>
 
 <p>
 Basic usage consists of creating a representation of a
@@ -67,7 +73,7 @@ Beware the difference between <em>diameter</em> (not capitalised) and
 <em>Diameter</em> (capitalised).
 The former refers to the Erlang application named diameter whose main
 api is defined here, the latter to Diameter protocol in the sense of
-RFC 3588.</p>
+&the_rfc;.</p>
 
 <p>
 The diameter application must be started before calling most functions
@@ -91,7 +97,7 @@ in this module.</p>
 <tag><c>UTF8String()</c></tag>
 <item>
 <p>
-Types corresponding to RFC 3588 AVP Data Formats.
+Types corresponding to &the_rfc; AVP Data Formats.
 Defined in &dict_data_types;.</p>
 
 <marker id="application_alias"/>
@@ -298,7 +304,7 @@ Has one of the following types.</p>
 <item>
 <p>
 An address list is available to the start function of a
-<seealso marker="diameter_transport">transport module</seealso>, which
+&transport_module;, which
 can return a new list for use in the subsequent CER or CEA.
 Host-IP-Address need not be specified if the transport start function
 returns an address list.</p>
@@ -312,7 +318,7 @@ returns an address list.</p>
 Origin-State-Id is optional but will be included in outgoing messages
 sent by diameter itself: CER/CEA, DWR/DWA and DPR/DPA.
 Setting a value of <c>0</c> (zero) is equivalent to not setting a
-value as documented in RFC 3588.
+value as documented in &the_rfc;.
 The function &origin_state_id;
 can be used as to retrieve a value that is computed when the diameter
 application is started.</p>
@@ -464,7 +470,7 @@ that matches no peer.</p>
 <p>
 The <c>host</c> and <c>realm</c> filters examine the
 outgoing request as passed to &call;,
-assuming that this is a record- or list-valued <c>&app_message;</c>,
+assuming that this is a record- or list-valued <c>&codec_message;</c>,
 and that the message contains at most one of each AVP.
 If this is not the case then the <c>{host|realm, &dict_DiameterIdentity;}</c>
 filters must be used to achieve the desired result.
@@ -529,8 +535,7 @@ connectivity.</p>
 
 <p>
 Note that a single <c>up</c>/<c>down</c> event for a given peer
-corresponds to one
-<seealso marker="diameter_app#Mod:peer_up-3">peer_up/peer_down</seealso>
+corresponds to one &app_peer_up;/&app_peer_down;
 callback for each of the Diameter applications negotiated during
 capablilities exchange.
 That is, the event communicates connectivity with the
@@ -677,7 +682,7 @@ info fields of forms other than the above.</p>
 The name of a service as passed to &start_service; and with which the
 service is identified.
 There can be at most one service with a given name on a given node.
-Note that <seealso marker="erts:erlang#make_ref-0">erlang:make_ref/0</seealso>
+Note that &make_ref;
 can be used to generate a service name that is somewhat unique.</p>
 
 <marker id="service_opt"/>
@@ -703,8 +708,7 @@ For an outgoing Diameter request, the relevant <c>&application_alias;</c> is
 passed to &call;, while for an
 incoming request the application identifier in the message
 header determines the application, the identifier being specified in
-the application's <seealso marker="diameter_dict">dictionary</seealso>
-file.</p>
+the application's &dictionary; file.</p>
 </item>
 
 <tag><c>{restrict_connections, false
@@ -749,7 +753,7 @@ as follows.</p>
 (H bsl N) bor (Id band ((1 bsl N) - 1))
 </pre>
 <p>
-Note that RFC 3588 requires that End-to-End identifiers remain unique
+Note that &the_rfc; requires that End-to-End identifiers remain unique
 for a period of at least 4 minutes and that this and the call rate
 places a lower bound on the appropriate values of <c>N</c>:
 at a rate of <c>R</c> requests per second an <c>N</c>-bit counter
@@ -951,7 +955,7 @@ Tc = &dict_Unsigned32;
 </pre>
 
 <p>
-For a connecting transport, the RFC 3588 Tc timer, in milliseconds.
+For a connecting transport, the &the_rfc; Tc timer, in milliseconds.
 Note that this timer determines the frequency with which a transport
 will attempt to establish a connection with its peer only <em>before</em>
 an initial connection is established: once there is an initial
@@ -1125,7 +1129,7 @@ its transports.</p>
 <type>
 <v>SvcName = &service_name;</v>
 <v>App = &application_alias;</v>
-<v>Request = &app_message;</v>
+<v>Request = &codec_message;</v>
 <v>Answer = term()</v>
 <v>Opt = &call_opt;</v>
 </type>
@@ -1618,7 +1622,7 @@ Return the list of started services.</p>
 Return a value for a Session-Id AVP.</p>
 
 <p>
-The value has the form required by section 8.8 of RFC 3588.
+The value has the form required by section 8.8 of &the_rfc;.
 Ident should be the Origin-Host of the peer from which
 the message containing the returned value will be sent.</p>
 
diff --git a/lib/diameter/doc/src/diameter_app.xml b/lib/diameter/doc/src/diameter_app.xml
index 304c69ebda..f4db625c71 100644
--- a/lib/diameter/doc/src/diameter_app.xml
+++ b/lib/diameter/doc/src/diameter_app.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="latin1" ?>
 <!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY message '<seealso marker="#message">message()</seealso>'>
+  <!ENTITY dict
+  '<seealso marker="diameter_dict#MESSAGE_RECORDS">diameter_dict(4)</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -124,39 +127,17 @@ mandatory values as the bare value.</p>
 
 <marker id="message"/>
 
-<tag><c>message() = record() | list()</c></tag>
+<tag><c>message() = &codec_message;</c></tag>
 <item>
 <p>
 The representation of a Diameter message as passed to
-&mod_call;.
-The record representation is as outlined in
-<seealso
-marker="diameter_dict#MESSAGE_RECORDS">diameter_dict(4)</seealso>:
-a message as defined in a dictionary file is encoded as a record with
-one field for each component AVP.
-Equivalently, a message can also be encoded as a list whose head is
-the atom-valued message name (the record name minus any
-prefix specified in the relevant dictionary file) and whose tail is a
-list of <c>{FieldName, FieldValue}</c> pairs.</p>
-
-<p>
-A third representation allows a message to be specified as a list
-whose head is a <c>#diameter_header{}</c> record and whose tail is a list
-of <c>#diameter_avp{}</c> records.
-This representation is used by diameter itself when relaying requests
-as directed by the return value of a
-&handle_request;
-callback.
-It differs from the other other two in that it bypasses the checks for
-messages that do not agree with their definitions in the dictionary in
-question (since relays agents must handle arbitrary request): messages
-are sent exactly as specified.</p>
+&mod_call; or returned from a &handle_request; callback.</p>
 
 </item>
 
 <marker id="packet"/>
 
-<tag><c>packet() = #diameter_packet{}</c></tag>
+<tag><c>packet() = &codec_packet;</c></tag>
 <item>
 <p>
 A container for incoming and outgoing Diameter messages that's passed
@@ -505,8 +486,7 @@ The application in which the callback takes place (that is, the
 callback module as configured with &mod_start_service;)
 is determined by the Application Identifier in the header of the
 incoming request message, the selected module being the one
-whose corresponding <seealso
-marker="diameter_dict#MESSAGE_RECORDS">dictionary</seealso> declares
+whose corresponding dictionary declares
 itself as defining either the application in question or the Relay
 application.</p>
 
@@ -526,8 +506,7 @@ The argument &packet; has the following signature.</p>
 The <c>msg</c> field will be <c>undefined</c> in case the request has
 been received in the relay application.
 Otherwise it contains the record representing the request as outlined
-in <seealso
-marker="diameter_dict#MESSAGE_RECORDS">diameter_dict(4)</seealso>.</p>
+in &dict;.</p>
 
 <p>
 The <c>errors</c> field specifies any Result-Code's identifying errors
@@ -579,7 +558,7 @@ where <c>Avps</c> sets the Origin-Host, Origin-Realm, the specified
 Result-Code and (if the request sent one) Session-Id AVP's.</p>
 
 <p>
-Note that RFC 3588 mandates that only answers with a 3xxx series
+Note that &the_rfc; mandates that only answers with a 3xxx series
 Result-Code (protocol errors) may set the E bit.
 Returning a non-3xxx value in a <c>protocol_error</c> tuple
 will cause the request process in question to fail.</p>
diff --git a/lib/diameter/doc/src/diameter_codec.xml b/lib/diameter/doc/src/diameter_codec.xml
new file mode 100644
index 0000000000..4a77d5435b
--- /dev/null
+++ b/lib/diameter/doc/src/diameter_codec.xml
@@ -0,0 +1,389 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY records
+  '<seealso marker="diameter_dict#MESSAGE_RECORDS">diameter_dict(4)</seealso>'>
+  <!ENTITY types
+  '<seealso marker="diameter_dict#DATA_TYPES">diameter_dict(4)</seealso>'>
+  <!ENTITY % also SYSTEM "seealso.ent" >
+  <!ENTITY % here SYSTEM "seehere.ent" >
+  %also;
+  %here;
+]>
+
+<erlref>
+<header>
+<copyright>
+<year>2012</year>
+<holder>Ericsson AB. All Rights Reserved.</holder>
+</copyright>
+<legalnotice>
+The contents of this file are subject to the Erlang Public License,
+Version 1.1, (the "License"); you may not use this file except in
+compliance with the License. You should have received a copy of the
+Erlang Public License along with this software. If not, it can be
+retrieved online at http://www.erlang.org/.
+
+Software distributed under the License is distributed on an "AS IS"
+basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+the License for the specific language governing rights and limitations
+under the License.
+
+</legalnotice>
+
+<title>diameter_codec(3)</title>
+<prepared>Anders Svensson</prepared>
+<responsible></responsible>
+<docno></docno>
+<approved></approved>
+<checked></checked>
+<date></date>
+<rev></rev>
+<file>diameter_codec.xml</file>
+</header>
+
+<module>diameter_codec</module>
+<modulesummary>Decode and encode of Diameter messages.</modulesummary>
+
+<description>
+
+<p>
+Incoming Diameter messages are decoded from binary() before being
+communicated to &man_app; callbacks.
+Similarly, outgoing Diameter messages are encoded into binary() before
+being passed to the appropriate &man_transport; module for
+transmission.
+The functions in this module implement this encode/decode.</p>
+
+<note>
+<p>
+Calls to this module are made by diameter itself as a consequence of
+configuration passed to &mod_start_service;.
+The encode/decode functions may also be useful for other purposes (eg.
+test) but the diameter user does not need to call them explicitly when
+sending and receiving messages using &mod_call; and the callback
+interface documented in &man_app;.</p>
+</note>
+
+<p>
+The &header; and &packet; records below
+are defined in diameter.hrl, which can be included as follows.</p>
+
+<pre>
+-include_lib("diameter/include/diameter.hrl").
+</pre>
+
+<p>
+Application-specific records are definied in the hrl
+files resulting from dictionary file compilation.</p>
+
+</description>
+
+<!-- ===================================================================== -->
+
+<section>
+<title>DATA TYPES</title>
+
+<p></p>
+
+<taglist>
+
+<marker id="integers"/>
+
+<tag><c>uint8()&nbsp; = 0..255</c></tag>
+<tag><c>uint24() = 0..16777215</c></tag>
+<tag><c>uint32() = 0..4294967295</c></tag>
+<item>
+<p>
+8-bit, 24-bit and 32-bit integers occurring in Diameter and AVP
+headers.</p>
+</item>
+
+<marker id="avp"/>
+
+<tag><c>avp() = #diameter_avp{}</c></tag>
+<item>
+<p>
+The application-neutral representation of an AVP.
+Primarily intended for use by relay applications that need to handle
+arbitrary Diameter applications.
+A service implementing a specific Diameter application
+(for which it configures a dictionary) can manipulate values of type
+&message; instead.</p>
+
+<p>
+Fields have the following types.</p>
+
+<taglist>
+
+<tag><c>code = uint32()</c></tag>
+<tag><c>is_mandatory = boolean()</c></tag>
+<tag><c>need_encryption = boolean()</c></tag>
+<tag><c>vendor_id = uint32() | undefined</c></tag>
+<item>
+<p>
+Values in the AVP header, corresponding to AVP Code, the M flag, P
+flags and Vendor-ID respectivelty.
+A Vendor-ID other than <c>undefined</c> implies a set V flag.</p>
+</item>
+
+<tag><c>data = iolist()</c></tag>
+<item>
+<p>
+The data bytes of the AVP.</p>
+</item>
+
+<tag><c>name = atom()</c></tag>
+<item>
+<p>
+The name of the AVP as defined in the dictionary file in question, or
+<c>undefined</c> if the AVP is unknown to the dictionary file in
+question.</p>
+</item>
+
+<tag><c>value = term()</c></tag>
+<item>
+<p>
+The decoded value of an AVP.
+Will be <c>undefined</c> on decode if the data bytes could
+not be decoded or the AVP is unknown.
+The type of a decoded value is as document in &types;.</p>
+</item>
+
+<tag><c>type = atom()</c></tag>
+<item>
+<p>
+The type of the AVP as specified in the dictionary file in question
+(or one it inherits).
+Possible types are <c>undefined</c> and the Diameter types:
+<c>OctetString</c>, <c>Integer32</c>, <c>Integer64</c>,
+<c>Unsigned32</c>, <c>Unsigned64</c>, <c>Float32</c>, <c>Float64</c>,
+<c>Grouped</c>, <c>Enumerated</c>, <c>Address</c>, <c>Time</c>,
+<c>UTF8String</c>, <c>DiameterIdentity</c>, <c>DiameterURI</c>,
+<c>IPFilterRule</c> and <c>QoSFilterRule</c>.</p>
+</item>
+
+</taglist>
+
+</item>
+
+<marker id="dictionary"/>
+
+<tag><c>dictionary() = module()</c></tag>
+<item>
+
+<p>
+The name of a generated dictionary module as generated by &man_compile;
+or &make_codec;.
+The interface provided by a dictionary module is an
+implementation detail that may change.</p>
+</item>
+
+<marker id="header"/>
+
+<tag><c>header() = #diameter_header{}</c></tag>
+<item>
+<p>
+The record representation of the Diameter header.
+Values in a &packet; returned by &decode; are as extracted from the
+incoming message.
+Values set in an &packet; passed to &encode; are preserved in the
+encoded binary(), with the exception of <c>length</c>, <c>cmd_code</c>
+and <c>application_id</c>, all of which are determined by the
+&dictionary; in question.</p>
+
+<note>
+<p>
+It is not necessary to set header fields explicitly in outgoing
+messages as diameter itself will set appropriate values.
+Setting inappropriate values can be useful for test purposes.</p>
+</note>
+
+<p>
+Fields have the following types.</p>
+
+<taglist>
+
+<tag><c>version = uint8()</c></tag>
+<tag><c>length = uint24()</c></tag>
+<tag><c>cmd_code = uint24()</c></tag>
+<tag><c>application_id = uint32()</c></tag>
+<tag><c>hop_by_hop_id = uint32()</c></tag>
+<tag><c>end_to_end_id = uint32()</c></tag>
+<item>
+<p>
+Values of the Version, Message Length, Command-Code, Application-ID,
+Hop-by-Hop Identifier and End-to-End Identifier fields of the Diameter
+header.</p>
+</item>
+
+<tag><c>is_request = boolean()</c></tag>
+<tag><c>is_proxiable = boolean()</c></tag>
+<tag><c>is_error = boolean()</c></tag>
+<tag><c>is_retransmitted = boolean()</c></tag>
+<item>
+<p>
+Values correspoding to the R(equest), P(roxiable), E(rror)
+and T(Potentially re-transmitted message) flags of the Diameter
+header.</p>
+</item>
+
+</taglist>
+
+</item>
+
+<marker id="message"/>
+
+<tag><c>message() = record() | list()</c></tag>
+<item>
+<p>
+The representation of a Diameter message as passed to
+&mod_call; or returned from a &app_handle_request; callback.
+The record representation is as outlined in &records;:
+a message as defined in a dictionary file is encoded as a record with
+one field for each component AVP.
+Equivalently, a message can also be encoded as a list whose head is
+the atom-valued message name (as specified in the relevant dictionary
+file) and whose tail is a list of <c>{AvpName, AvpValue}</c> pairs.</p>
+
+<p>
+Another list-valued representation allows a message to be specified
+as a list whose head is a &header; and whose tail is an &avp; list.
+This representation is used by diameter itself when relaying requests
+as directed by the return value of a &app_handle_request; callback.
+It differs from the other other two in that it bypasses the checks for
+messages that do not agree with their definitions in the dictionary in
+question: messages are sent exactly as specified.</p>
+
+</item>
+
+<marker id="packet"/>
+
+<tag><c>packet() = #diameter_packet{}</c></tag>
+<item>
+<p>
+A container for incoming and outgoing Diameter messages.
+Fields have the following types.</p>
+
+<taglist>
+
+<tag><c>header = &header; | undefined</c></tag>
+<item>
+<p>
+The Diameter header of the message.
+Can be (and typically should be) <c>undefined</c> for an outgoing
+message in a non-relay application, in which case diameter provides
+appropriate values.</p>
+</item>
+
+<tag><c>avps = [&avp;] | undefined</c></tag>
+<item>
+<p>
+The AVPs of the message.
+Ignored for an outgoing message if the <c>msg</c> field is set to a
+value other than <c>undefined</c>.</p>
+</item>
+
+<tag><c>msg = &message; | undefined</c></tag>
+<item>
+<p>
+The incoming/outgoing message.
+For an incoming message, a record if the message can be
+decoded in a non-relay application, <c>undefined</c> otherwise.
+For an outgoing message, setting a <c>[&header; | &avp;]</c> list is
+equivalent to setting the <c>header</c> and <c>avps</c> fields to the
+corresponding values.</p>
+
+<warning>
+<p>
+A record-valued <c>msg</c> field does <b>not</b> imply an absence of
+decode errors.
+The <c>errors</c> field should also be examined.</p>
+</warning>
+
+</item>
+
+<tag><c>bin = binary()</c></tag>
+<item>
+<p>
+The incoming message prior to encode or the outgoing message after
+encode.</p>
+</item>
+
+<tag><c>errors = [5000..5999 | {5000..5999, avp()}]</c></tag>
+<item>
+<p>
+Errors detected at decode of an incoming message, as identified by
+a corresponding 5xxx series Result-Code (Permanent Failures).
+For an incoming request, these should be used to formulate an
+appropriate answer as documented for the &app_handle_request;
+callback in &man_app;.
+For an incoming answer, the &mod_application_opt;
+<c>answer_errors</c> determines the behaviour.</p>
+</item>
+
+<tag><c>transport_data = term()</c></tag>
+<item>
+<p>
+An arbitrary term of meaning only to the transport process in
+question, as documented in &man_transport;.</p>
+</item>
+
+</taglist>
+
+</item>
+
+</taglist>
+
+</section>
+
+<!-- ===================================================================== -->
+
+<funcs>
+
+<func>
+<name>decode(Mod, Bin) -> Pkt</name>
+<fsummary>Decode a Diameter message.</fsummary>
+<type>
+<v>Mod = &dictionary;</v>
+<v>Bin = binary()</v>
+<v>Pkt = &packet;</v>
+</type>
+<desc>
+
+<p>
+Decode a Diameter message.</p>
+
+</desc>
+</func>
+
+<func>
+<name>encode(Mod, Msg) -> Pkt</name>
+<fsummary>Encode a Diameter message.</fsummary>
+<type>
+<v>Mod = &dictionary;</v>
+<v>Msg = &message; | &packet;</v>
+<v>Pkt = &packet;</v>
+</type>
+<desc>
+
+<p>
+Encode a Diameter message.
+</p>
+
+</desc>
+</func>
+
+</funcs>
+
+<!-- ===================================================================== -->
+<!-- ===================================================================== -->
+
+<section>
+<title>SEE ALSO</title>
+
+<p>
+&man_compile;, &man_app;, &man_dict;, &man_make;</p>
+
+</section>
+
+</erlref>
diff --git a/lib/diameter/doc/src/diameter_compile.xml b/lib/diameter/doc/src/diameter_compile.xml
index eb6de80c11..0bd7ad1789 100644
--- a/lib/diameter/doc/src/diameter_compile.xml
+++ b/lib/diameter/doc/src/diameter_compile.xml
@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="iso-8859-1" ?>
 <!DOCTYPE comref SYSTEM "comref.dtd" [
+  <!ENTITY dictionary
+  '<seealso marker="diameter_dict">dictionary file</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -36,12 +38,14 @@ supplied.
 <description>
 
 <p>
-The diameterc utility is used to compile diameter
-<seealso marker="diameter_dict">dictionary files</seealso>
-into Erlang source.
-The resulting source implements the interface diameter requires
+The diameterc utility is used to compile a diameter
+&dictionary; into Erlang source.
+The resulting source implements the interface diameter required
 to encode and decode the dictionary's messages and AVP's.</p>
 
+<p>
+The module &man_make; provides an alternate compilation interface.</p>
+
 </description>
 
 <section>
@@ -52,53 +56,52 @@ to encode and decode the dictionary's messages and AVP's.</p>
 <tag><![CDATA[diameterc [<options>] <file>]]></tag>
 <item>
 <p>
-Compiles a single dictionary file. Valid options are as follows.</p>
-
-<!-- Leave -h/d/v undocumented, except for the usage message from the
-     utility itself. -->
-
-<taglist>
-<tag><![CDATA[-o <dir>]]></tag>
-<item>
-<p>
-Specifies the directory into which the generated source should be written.
-Defaults to the current working directory.</p>
-</item>
+Compile a single dictionary file to Erlang source.
+Valid options are as follows.</p>
 
 <tag><![CDATA[-i <dir>]]></tag>
 <item>
 <p>
-Specifies a directory to add to the code path.
+Prepend the specified directory to the code path.
 Use to point at beam files compiled from inherited dictionaries,
-<c>@inherits</c> in a dictionary file creating a beam dependency, not
-an erl/hrl dependency.</p>
+<c>&dict_inherits;</c> in a dictionary file creating a beam
+dependency, not an erl/hrl dependency.</p>
 
 <p>
 Multiple <c>-i</c> options can be specified.</p>
 </item>
 
+<taglist>
+<tag><![CDATA[-o <dir>]]></tag>
+<item>
+<p>
+Write generated source to the specified directory.
+Defaults to the current working directory.</p>
+</item>
+
 <tag><![CDATA[-E]]></tag>
 <tag><![CDATA[-H]]></tag>
 <item>
 <p>
-Supresses erl and hrl generation, respectively.</p>
+Supress erl and hrl generation, respectively.</p>
 </item>
 
 <tag><![CDATA[--name <name>]]></tag>
 <tag><![CDATA[--prefix <prefix>]]></tag>
 <item>
 <p>
-Set <c>@name</c> and <c>@prefix</c> in the dictionary,
-respectively.
+Set <c>&dict_name;</c> or <c>&dict_prefix;</c> to the specified
+string.
 Overrides any setting in the file itself.</p>
 </item>
 
 <tag><![CDATA[--inherits <dict>]]></tag>
 <item>
 <p>
-Append an <c>@inherits</c> to the dictionary before compiling.
-Specifying <c>'-'</c> as the dictionary has the effect of clearing any
-previous inherits, causing them to be ignored.</p>
+Append &dict_inherits; of the specified module.
+Specifying <c>"-"</c> has the effect of discarding clearing any
+previous inherits, both in the dictionary file and on the options
+list.</p>
 
 <p>
 Multiple <c>--inherits</c> options can be specified.</p>
@@ -127,7 +130,7 @@ Returns 0 on success, non-zero on failure.</p>
 <title>SEE ALSO</title>
 
 <p>
-&man_dict;</p>
+&man_make;, &man_dict;</p>
 
 </section>
 
diff --git a/lib/diameter/doc/src/diameter_dict.xml b/lib/diameter/doc/src/diameter_dict.xml
index 4a6cccc276..8b0687a22e 100644
--- a/lib/diameter/doc/src/diameter_dict.xml
+++ b/lib/diameter/doc/src/diameter_dict.xml
@@ -1,5 +1,11 @@
 <?xml version="1.0" encoding="latin1" ?>
 <!DOCTYPE erlref SYSTEM "fileref.dtd" [
+  <!ENTITY format
+           '<seealso marker="#FILE_FORMAT">FILE FORMAT</seealso>'>
+  <!ENTITY records
+           '<seealso marker="#MESSAGE_RECORDS">MESSAGE RECORDS</seealso>'>
+  <!ENTITY types
+           '<seealso marker="#DATA_TYPES">DATA TYPES</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -45,34 +51,33 @@ under the License.
 
 <description>
 <p>
-A diameter service as configured with &mod_start_service;
+A diameter service, as configured with &mod_start_service;,
 specifies one or more supported Diameter applications.
 Each Diameter application specifies a dictionary module that knows how
 to encode and decode its messages and AVPs.
 The dictionary module is in turn generated from a file that defines
 these messages and AVPs.
-The format of such a file is defined in
-<seealso marker="#FILE_FORMAT">FILE FORMAT</seealso> below.
+The format of such a file is defined in &format; below.
 Users add support for their specific applications by creating
 dictionary files, compiling them to Erlang modules using
-<seealso marker="diameterc">diameterc</seealso> and configuring the
+either &man_compile; or &man_make; and configuring the
 resulting dictionaries modules on a service.</p>
 
 <p>
-The codec generation also results in a hrl file that defines records
-for the messages and grouped AVPs defined for the application, these
-records being what a user of the diameter application sends and receives.
-(Modulo other available formats as discussed in &man_app;.)
+Dictionary module generation also results in a hrl file that defines
+records for the messages and Grouped AVPs defined by the
+dictionary, these records being what a user of the diameter
+application sends and receives, modulo other possible formats as
+discussed in &man_app;.
 These records and the underlying Erlang data types corresponding to
-Diameter data formats are discussed in <seealso
-marker="#MESSAGE_RECORDS">MESSAGE RECORDS</seealso> and <seealso
-marker="#DATA_TYPES">DATA TYPES</seealso> respectively.
-The generated hrl also contains defines for the possible values of
+Diameter data formats are discussed in &records; and &types;
+respectively.
+The generated hrl also contains macro definitions for the possible values of
 AVPs of type Enumerated.</p>
 
 <p>
 The diameter application includes three dictionary modules
-corresponding to applications defined in section 2.4 of RFC 3588:
+corresponding to applications defined in section 2.4 of &the_rfc;:
 <c>diameter_gen_base_rfc3588</c> for the Diameter Common Messages
 application with application identifier 0,
 <c>diameter_gen_accounting</c> for the Diameter Base Accounting
@@ -111,6 +116,8 @@ The order in which sections are specified is unimportant.</p>
 
 <taglist>
 
+<marker id="id"/>
+
 <tag><c>@id Number</c></tag>
 <item>
 <p>
@@ -134,6 +141,8 @@ Example:</p>
 
 </item>
 
+<marker id="name"/>
+
 <tag><c>@name Mod</c></tag>
 <item>
 <p>
@@ -155,6 +164,8 @@ Example:</p>
 
 </item>
 
+<marker id="prefix"/>
+
 <tag><c>@prefix Name</c></tag>
 <item>
 <p>
@@ -178,6 +189,8 @@ Example:</p>
 
 </item>
 
+<marker id="vendor"/>
+
 <tag><c>@vendor Number Name</c></tag>
 <item>
 <p>
@@ -198,6 +211,8 @@ Example:</p>
 
 </item>
 
+<marker id="avp_vendor_id"/>
+
 <tag><c>@avp_vendor_id Number</c></tag>
 <item>
 <p>
@@ -218,6 +233,8 @@ Region-Set
 
 </item>
 
+<marker id="inherits"/>
+
 <tag><c>@inherits Mod</c></tag>
 <item>
 <p>
@@ -241,7 +258,7 @@ is equivalent to using <c>@avp_vendor_id</c> with a copy of the
 dictionary's definitions but the former makes for easier reuse.</p>
 
 <p>
-All dictionaries should typically inherit RFC3588 AVPs from
+All dictionaries should typically inherit &the_rfc; AVPs from
 <c>diameter_gen_base_rfc3588</c>.</p>
 
 <p>
@@ -253,6 +270,8 @@ Example:</p>
 
 </item>
 
+<marker id="avp_types"/>
+
 <tag><c>@avp_types</c></tag>
 <item>
 <p>
@@ -263,7 +282,7 @@ The section consists of definitions of the form</p>
 
 <p>
 where Code is the integer AVP code, Type identifies an AVP Data Format
-as defined in <seealso marker="#DATA_TYPES">DATA TYPES</seealso> below,
+as defined in section &types; below,
 and Flags is a string of V, M and P characters indicating the flags to be
 set on an outgoing AVP or a single <c>'-'</c> (minus) character if
 none are to be set.</p>
@@ -280,13 +299,13 @@ Requested-Information  353  Enumerated   V
 
 <warning>
 <p>
-The P flag has been deprecated by the Diameter Maintenance
-and Extensions Working Group of the IETF and should be omitted
-to conform to the current draft standard.</p>
+The P flag has been deprecated by &the_rfc;.</p>
 </warning>
 
 </item>
 
+<marker id="custom_types"/>
+
 <tag><c>@custom_types Mod</c></tag>
 <item>
 <p>
@@ -308,6 +327,8 @@ Framed-IP-Address
 </pre>
 </item>
 
+<marker id="codecs"/>
+
 <tag><c>@codecs Mod</c></tag>
 <item>
 <p>
@@ -325,12 +346,14 @@ Framed-IP-Address
 </pre>
 </item>
 
+<marker id="messages"/>
+
 <tag><c>@messages</c></tag>
 <item>
 <p>
 Defines the messages of the application.
 The section content consists of definitions of the form specified in
-section 3.2 of RFC 3588, "Command Code ABNF specification".</p>
+section 3.2 of &the_rfc;, "Command Code Format Specification".</p>
 
 <!-- RFC 4740 RTR/RTA -->
 <pre>
@@ -370,13 +393,15 @@ RTA ::= &lt; Diameter Header: 287, PXY >
 
 </item>
 
+<marker id="grouped"/>
+
 <tag><c>@grouped</c></tag>
 <item>
 <p>
 Defines the contents of the AVPs of the application having type
 Grouped.
 The section content consists of definitions of the form specified in
-section 4.4 of RFC 3588, "Grouped AVP Values".</p>
+section 4.4 of &the_rfc;, "Grouped AVP Values".</p>
 
 <p>
 Example:</p>
@@ -395,6 +420,8 @@ Specifying a Vendor-Id in the definition of a grouped AVP is
 equivalent to specifying it with <c>@avp_vendor_id</c>.</p>
 </item>
 
+<marker id="enum"/>
+
 <tag><c>@enum Name</c></tag>
 <item>
 <p>
@@ -421,6 +448,8 @@ REMOVE_SIP_SERVER        3
 </pre>
 </item>
 
+<marker id="end"/>
+
 <tag><c>@end</c></tag>
 <item>
 <p>
@@ -447,8 +476,8 @@ The hrl generated from a dictionary specification defines records for the
 messages and grouped AVPs defined in <c>@messages</c> and
 <c>@grouped</c> sections.
 For each message or grouped AVP definition, a record is defined whose
-name is the message or AVP name prefixed with any dictionary prefix
-defined with <c>@prefix</c> and whose fields are the names of the AVPs
+name is the message or AVP name, prefixed with any dictionary prefix
+defined with <c>@prefix</c>, and whose fields are the names of the AVPs
 contained in the message or grouped AVP in the order specified in the
 definition in question.
 For example, the grouped AVP</p>
@@ -476,7 +505,7 @@ type and number of times the AVP can occur.
 In particular, an AVP which is specified as occurring exactly once is
 encoded as a value of the AVP's type while an AVP with any other
 specification is encoded as a list of values of the AVP's type.
-The AVP's type is as specified in the AVP definition, the RFC 3588
+The AVP's type is as specified in the AVP definition, the &the_rfc;
 types being described below.</p>
 
 <marker id="DATA_TYPES"/>
@@ -489,7 +518,7 @@ types being described below.</p>
 
 <p>
 The data formats defined in sections 4.2 ("Basic AVP Data
-Formats") and 4.3 ("Derived AVP Data Formats") of RFC 3588 are encoded
+Formats") and 4.3 ("Derived AVP Data Formats") of &the_rfc; are encoded
 as values of the types defined here.
 Values are passed to &mod_call;
 in a request record when sending a request, returned in a resulting
@@ -564,8 +593,8 @@ where
 
 <p>
 Additionally, values that can be encoded are
-limited by way of their encoding as four octets as required by RFC
-3588 with the required extension from RFC 2030.
+limited by way of their encoding as four octets as required by
+&the_rfc; with the required extension from RFC 2030.
 In particular, only values between <c>{{1968,1,20},{3,14,8}}</c>
 and <c>{{2104,2,26},{9,42,23}}</c> (both inclusive) can be encoded.</p>
 
@@ -609,7 +638,7 @@ where
 On encode, fields port, transport and protocol default to 3868, sctp
 and diameter respectively.
 The grammar of an OctetString-valued DiameterURI() is as specified in
-section 4.3 of RFC 3588.
+section 4.3 of &the_rfc;.
 The record representation is used on decode.</p>
 
 <marker id="Enumerated"/>
@@ -640,7 +669,7 @@ Values of these types are not currently parsed by diameter.</p>
 <title>SEE ALSO</title>
 
 <p>
-&man_compile;, &man_main;, &man_app;</p>
+&man_compile;, &man_main;, &man_app;, &man_codec;, &man_make;</p>
 
 </section>
 
diff --git a/lib/diameter/doc/src/diameter_intro.xml b/lib/diameter/doc/src/diameter_intro.xml
index bc2afbd453..fd578ccf45 100644
--- a/lib/diameter/doc/src/diameter_intro.xml
+++ b/lib/diameter/doc/src/diameter_intro.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="latin1" ?>
-<!DOCTYPE chapter SYSTEM "chapter.dtd">
+<!DOCTYPE chapter SYSTEM "chapter.dtd" [
+  <!ENTITY % also SYSTEM "seealso.ent">
+  %also;
+]>
 
 <chapter>
 <header>
@@ -35,7 +38,7 @@ under the License.
 
 <p>
 The diameter application is an implementation of the Diameter protocol
-as defined by RFC 3588.
+as defined by &the_rfc;.
 It supports arbitrary Diameter applications by way of a
 <em>dictionary</em> interface that allows messages and AVP's to be
 defined and input into diameter as configuration.
@@ -86,9 +89,9 @@ dictionary module
 that provide encode/decode functionality for outgoing/incoming
 Diameter messages belonging to the application.
 A dictionary module is generated from a <seealso
-marker="diameter_dict">specification file</seealso> using the <seealso
+marker="diameter_dict">dictionary file</seealso> using the <seealso
 marker="diameterc">diameterc</seealso> utility.
-Dictionaries for the RFC 3588 Diameter Common Messages, Base
+Dictionaries for the &the_rfc; Diameter Common Messages, Base
 Accounting and Relay applications are provided with the diameter
 application.</p>
 
diff --git a/lib/diameter/doc/src/diameter_make.xml b/lib/diameter/doc/src/diameter_make.xml
new file mode 100644
index 0000000000..da6124310e
--- /dev/null
+++ b/lib/diameter/doc/src/diameter_make.xml
@@ -0,0 +1,144 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY filename
+  '<seealso marker="kernel:file#type-name">file:name()</seealso>'>
+  <!ENTITY dictionary
+  '<seealso marker="diameter_dict">dictionary file</seealso>'>
+  <!ENTITY % also SYSTEM "seealso.ent" >
+  <!ENTITY % here SYSTEM "seehere.ent" >
+  %also;
+  %here;
+]>
+
+<erlref>
+<header>
+<copyright>
+<year>2012</year>
+<holder>Ericsson AB. All Rights Reserved.</holder>
+</copyright>
+<legalnotice>
+The contents of this file are subject to the Erlang Public License,
+Version 1.1, (the "License"); you may not use this file except in
+compliance with the License. You should have received a copy of the
+Erlang Public License along with this software. If not, it can be
+retrieved online at http://www.erlang.org/.
+
+Software distributed under the License is distributed on an "AS IS"
+basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+the License for the specific language governing rights and limitations
+under the License.
+
+</legalnotice>
+
+<title>diameter_make(3)</title>
+<prepared>Anders Svensson</prepared>
+<responsible></responsible>
+<docno></docno>
+<approved></approved>
+<checked></checked>
+<date></date>
+<rev></rev>
+<file>diameter_make.xml</file>
+</header>
+
+<module>diameter_make</module>
+<modulesummary>Diameter dictionary compilation.</modulesummary>
+
+<description>
+
+<p>
+The function &codec; is used to compile a diameter
+&dictionary; into Erlang source.
+The resulting source implements the interface diameter required
+to encode and decode the dictionary's messages and AVP's.</p>
+
+<p>
+The utility &man_compile; provides an alternate compilation
+interface.</p>
+
+</description>
+
+<!-- ===================================================================== -->
+
+<funcs>
+
+<func>
+<name>codec(Path::string(), [Opt]) -> ok | {error, Reason}</name>
+<fsummary>Compile a dictionary file into Erlang source.</fsummary>
+<desc>
+
+<p>
+Compile a single dictionary file to Erlang source.
+<c>Opt</c> can have the following types.</p>
+
+<taglist>
+
+<tag><c>{include, Dir::string()}</c></tag>
+<item>
+<p>
+Prepend the specified directory to the code path.
+Use to point at beam files compiled from inherited dictionaries,
+<c>&dict_inherits;</c> in a dictionary file creating a beam
+dependency, not an erl/hrl dependency.</p>
+
+<p>
+Multiple <c>include</c> options can be specified.</p>
+</item>
+
+<tag><c>{outdir, Dir::string()}</c></tag>
+<item>
+<p>
+Write generated source to the specified directory.
+Defaults to the current working directory.</p>
+</item>
+
+<tag><c>{name|prefix, string()}</c></tag>
+<item>
+<p>
+Set <c>&dict_name;</c> or <c>&dict_prefix;</c> to the specified
+string.
+Overrides any setting in the file itself.</p>
+</item>
+
+<tag><c>{inherits, Mod::string()}</c></tag>
+<item>
+<p>
+Append &dict_inherits; of the specified module.
+Specifying <c>"-"</c> has the effect of discarding clearing any
+previous inherits, both in the dictionary file and on the options
+list.</p>
+
+<p>
+Multiple <c>inherits</c> options can be specified.</p>
+</item>
+
+</taglist>
+
+</desc>
+</func>
+
+</funcs>
+
+<!-- ===================================================================== -->
+
+<section>
+<title>BUGS</title>
+
+<p>
+All options are string-valued.
+In particular, it is not currently possible to
+an &dict_inherits; module as an atom() or a path as a &filename;</p>
+
+</section>
+
+<!-- ===================================================================== -->
+
+<section>
+<title>SEE ALSO</title>
+
+<p>
+&man_compile;, &man_dict;</p>
+
+</section>
+
+</erlref>
diff --git a/lib/diameter/doc/src/diameter_sctp.xml b/lib/diameter/doc/src/diameter_sctp.xml
index a023a9bc08..5e3fd5eaf1 100644
--- a/lib/diameter/doc/src/diameter_sctp.xml
+++ b/lib/diameter/doc/src/diameter_sctp.xml
@@ -1,5 +1,11 @@
 <?xml version="1.0" encoding="latin1" ?>
 <!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY gen_sctp '<seealso marker="kernel:gen_sctp">gen_sctp(3)</seealso>'>
+  <!ENTITY gen_sctp_open1
+  '<seealso marker="kernel:gen_sctp#open-1">gen_sctp:open/1</seealso>'>
+  <!ENTITY ip_address
+  '<seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso>'>
+  <!ENTITY inet '<seealso marker="kernel:inet">inet(3)</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -43,8 +49,7 @@ under the License.
 <description>
 
 <p>
-This module implements diameter transport over SCTP using <seealso
-marker="kernel:gen_sctp">gen_sctp</seealso>.
+This module implements diameter transport over SCTP using &gen_sctp;.
 It can be specified as the value of a transport_module option to
 &mod_add_transport;
 and implements the behaviour documented in
@@ -65,9 +70,9 @@ and implements the behaviour documented in
 <v>Type = connect | accept</v>
 <v>Ref = &mod_transport_ref;</v>
 <v>Svc = #diameter_service{}</v>
-<v>Opt = {raddr, <seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso>} | {rport, integer()} | term()</v>
+<v>Opt = {raddr, &ip_address;} | {rport, integer()} | term()</v>
 <v>Pid = pid()</v>
-<v>LAddr = <seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso></v>
+<v>LAddr = &ip_address;</v>
 <v>Reason = term()</v>
 </type>
 <desc>
@@ -84,8 +89,7 @@ unspecified.
 More than one <c>raddr</c> option can be specified, in which case the
 connecting transport in question attempts each in sequence until
 an association is established.
-Remaining options are any accepted by <seealso
-marker="kernel:gen_sctp#open-1">gen_sctp:open/1</seealso>, with the exception
+Remaining options are any accepted by &gen_sctp_open1;, with the exception
 of options <c>mode</c>, <c>binary</c>, <c>list</c>, <c>active</c>
 and <c>sctp_events</c>.
 Note that options <c>ip</c> and <c>port</c> specify the local address
@@ -102,14 +106,12 @@ connecting transport.</p>
 <warning>
 <p>
 An insufficiently large receive buffer may result in a peer having to
-resend incoming messages: set the <seealso
-marker="kernel:inet">inet(3)</seealso> option <c>recbuf</c> to increase
+resend incoming messages: set the &inet; option <c>recbuf</c> to increase
 the buffer size.</p>
 
 <p>
 An insufficiently large send buffer may result in outgoing messages
-being discarded: set the <seealso
-marker="kernel:inet">inet(3)</seealso> option <c>sndbuf</c> to increase
+being discarded: set the &inet; option <c>sndbuf</c> to increase
 the buffer size.</p>
 </warning>
 
@@ -145,10 +147,7 @@ outbound streams.</p>
 <title>SEE ALSO</title>
 
 <p>
-&man_main;,
-&man_transport;,
-<seealso marker="kernel:gen_sctp">gen_sctp(3)</seealso>,
-<seealso marker="kernel:inet">inet(3)</seealso></p>
+&man_main;, &man_transport;, &gen_sctp;, &inet;</p>
 
 </section>
 
diff --git a/lib/diameter/doc/src/diameter_soc.xml b/lib/diameter/doc/src/diameter_soc.xml
index 6b9ef9f756..16f6b9d5bb 100644
--- a/lib/diameter/doc/src/diameter_soc.xml
+++ b/lib/diameter/doc/src/diameter_soc.xml
@@ -1,11 +1,15 @@
 <?xml version="1.0" encoding="latin1" ?>
-<!DOCTYPE chapter SYSTEM "chapter.dtd">
+<!DOCTYPE chapter SYSTEM "chapter.dtd" [
+  <!ENTITY % also SYSTEM "seealso.ent" >
+  %also;
+]>
 
 <chapter>
 
 <header>
 <copyright>
 <year>2011</year>
+<year>2012</year>
 <holder>Ericsson AB. All Rights Reserved.</holder>
 </copyright>
 
@@ -41,38 +45,20 @@ Known points of questionable or non-compliance.</p>
 <!-- ===================================================================== -->
 
 <section>
-<title>RFC 3588</title>
+<title>&the_rfc;</title>
 
 <list>
 
 <item>
 <p>
-The End-to-End Security framework (section 2.9) isn't implemented
-since it is largely unspecified.
-The document that was to describe it
-(reference [AAACMS]) was abandoned in an uncompleted state several
-years ago and the current draft RFC deprecates the framework,
-including the P Flag in the AVP header.</p>
-</item>
-
-<item>
-<p>
-There is no TLS support over SCTP.
-RFC 3588 requires that a Diameter server support TLS but in
-practise this seems to mean TLS over SCTP since there are limitations
-with running over SCTP: see RFC 6083 (DTLS over SCTP), which is a
-response to RFC 3436 (TLS over SCTP).
-The current RFC 3588 draft acknowledges this by equating
-TLS with TLS/TCP and DTLS/SCTP but we do not yet support DTLS.</p>
+There is no support for DTLS over SCTP.</p>
 </item>
 
 <item>
 <p>
 There is no explicit support for peer discovery (section 5.2).
 It can possibly be implemented on top of diameter as is but this is
-probably something that diameter should do.
-The current draft deprecates portions of the original RFC's mechanisms
-however.</p>
+probably something that diameter should do.</p>
 </item>
 
 <item>
diff --git a/lib/diameter/doc/src/diameter_tcp.xml b/lib/diameter/doc/src/diameter_tcp.xml
index be8a938115..e3b8c733b7 100644
--- a/lib/diameter/doc/src/diameter_tcp.xml
+++ b/lib/diameter/doc/src/diameter_tcp.xml
@@ -1,5 +1,22 @@
 <?xml version="1.0" encoding="latin1" ?>
 <!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY gen_tcp_connect3
+  '<seealso marker="kernel:gen_tcp#connect-3">gen_tcp:connect/3</seealso>'>
+  <!ENTITY gen_tcp_listen2
+  '<seealso marker="kernel:gen_tcp#listen-2">gen_tcp:listen/2</seealso>'>
+  <!ENTITY ip_address
+  '<seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso>'>
+  <!ENTITY ssl_connect2
+  '<seealso marker="ssl:ssl#connect-2">ssl:connect/2</seealso>'>
+  <!ENTITY ssl_connect3
+  '<seealso marker="ssl:ssl#connect-3">ssl:connect/3</seealso>'>
+  <!ENTITY ssl_accept2
+  '<seealso marker="ssl:ssl#ssl_accept-2">ssl:ssl_accept/2</seealso>'>
+  <!ENTITY ssl_listen2
+  '<seealso marker="ssl:ssl#listen-2">ssl:listen/2</seealso>'>
+  <!ENTITY gen_tcp '<seealso marker="kernel:gen_tcp">gen_tcp(3)</seealso>'>
+  <!ENTITY inet '<seealso marker="kernel:inet">inet(3)</seealso>'>
+  <!ENTITY ssl '<seealso marker="ssl:ssl">ssl(3)</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -43,14 +60,13 @@ under the License.
 <description>
 
 <p>
-This module implements diameter transport over TCP using <seealso
-marker="kernel:gen_tcp">gen_tcp</seealso>.
+This module implements diameter transport over TCP using &gen_tcp;.
 It can be specified as the value of a <c>transport_module</c> option to
 &mod_add_transport;
 and implements the behaviour documented in
 &man_transport;.
 TLS security is supported, both as an upgrade following
-capabilities exchange as specified by RFC 3588 and
+capabilities exchange as specified by &the_rfc; and
 at connection establishment as in the current draft standard.</p>
 
 <p>
@@ -74,9 +90,9 @@ before configuring TLS capability on diameter transports.</p>
 <v>Svc = #diameter_service{}</v>
 <v>Opt = OwnOpt | SslOpt | TcpOpt</v>
 <v>Pid = pid()</v>
-<v>LAddr = <seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso></v>
+<v>LAddr = &ip_address;</v>
 <v>Reason = term()</v>
-<v>OwnOpt = {raddr, <seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso>}
+<v>OwnOpt = {raddr, &ip_address;}
           | {rport, integer()}
           | {port, integer()}</v>
 <v>SslOpt = {ssl_options, true | list()}</v>
@@ -95,16 +111,12 @@ transport.
 Option <c>ssl_options</c> must be specified for a transport
 that should support TLS: a value of <c>true</c> results in a
 TLS handshake immediately upon connection establishment while
-<c>list()</c> specifies options to be passed to <seealso
-marker="ssl:ssl#connect-2">ssl:connect/2</seealso> or
-<seealso marker="ssl:ssl#ssl_accept-2">ssl:ssl_accept/2</seealso>
+<c>list()</c> specifies options to be passed to &ssl_connect2; or
+&ssl_accept2;
 after capabilities exchange if TLS is negotiated.
-Remaining options are any accepted by <seealso
-marker="ssl:ssl#connect-3">ssl:connect/3</seealso> or <seealso
-marker="kernel:gen_tcp#connect-3">gen_tcp:connect/3</seealso> for
-a connecting transport, or <seealso
-marker="ssl:ssl#listen-2">ssl:listen/2</seealso> or <seealso
-marker="kernel:gen_tcp#listen-2">gen_tcp:listen/2</seealso> for
+Remaining options are any accepted by &ssl_connect3; or
+&gen_tcp_connect3; for
+a connecting transport, or &ssl_listen2; or &gen_tcp_listen2; for
 a listening transport, depending on whether or not <c>{ssl_options, true}</c>
 has been specified.
 Options <c>binary</c>,
@@ -150,11 +162,7 @@ The returned local address list has length one.</p>
 <title>SEE ALSO</title>
 
 <p>
-&man_main;,
-&man_transport;,
-<seealso marker="kernel:gen_tcp">gen_tcp(3)</seealso>,
-<seealso marker="kernel:inet">inet(3)</seealso>,
-<seealso marker="ssl:ssl">ssl(3)</seealso></p>
+&man_main;, &man_transport;, &gen_tcp;, &inet;, &ssl;</p>
 
 </section>
 
diff --git a/lib/diameter/doc/src/diameter_transport.xml b/lib/diameter/doc/src/diameter_transport.xml
index 0507af63a8..55b531155f 100644
--- a/lib/diameter/doc/src/diameter_transport.xml
+++ b/lib/diameter/doc/src/diameter_transport.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="latin1" ?>
 <!DOCTYPE erlref SYSTEM "erlref.dtd" [
+  <!ENTITY message '<seealso marker="#message">message()</seealso>'>
+  <!ENTITY ip_address
+  '<seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso>'>
   <!ENTITY % also SYSTEM "seealso.ent" >
   <!ENTITY % here SYSTEM "seehere.ent" >
   %also;
@@ -50,16 +53,49 @@ diameter starts a transport process and a message interface with which
 the transport process communicates with the process that starts it (aka its
 parent).</p>
 
-<marker id="start"/>
 </description>
 
 <!-- ===================================================================== -->
 
+<section>
+<title>DATA TYPES</title>
+
+<taglist>
+
+<marker id="message"/>
+
+<tag><c>message() = binary() | &codec_packet;</c></tag>
+<item>
+<p>
+A Diameter message as passed over the transport interface.</p>
+
+<p>
+For an inbound message from a transport process, a &codec_packet; must
+contain the received message in its <c>bin</c> field.
+In the case of an inbound request, any value set in the
+<c>transport_data</c> field will passed back to the transport module
+in the corresponding answer message, unless the sender supplies
+another value.</p>
+
+<p>
+For an outbound message to a transport process, a &codec_packet; has a
+value other than <c>undefined</c> in its <c>transport_data</c> field
+and has the binary() to send in its <c>bin</c> field.</p>
+</item>
+
+</taglist>
+
+</section>
+
+<!-- ===================================================================== -->
+
 <funcs>
 
 <func>
 <name>Mod:start({Type, Ref}, Svc, Config)
-         -> {ok, Pid} | {ok, Pid, LAddrs} | {error, Reason}</name>
+         -> {ok, Pid}
+          | {ok, Pid, LAddrs}
+          | {error, Reason}</name>
 <fsummary>Start a transport process.</fsummary>
 <type>
 <v>Type = connect | accept</v>
@@ -67,7 +103,7 @@ parent).</p>
 <v>Svc = #diameter_service{}</v>
 <v>Config = term()</v>
 <v>Pid = pid()</v>
-<v>LAddrs = [<seealso marker="kernel:inet#type-ip_address">inet:ip_address()</seealso>]</v>
+<v>LAddrs = [&ip_address;]</v>
 <v>Reason = term()</v>
 </type>
 <desc>
@@ -79,8 +115,8 @@ A transport process maintains a connection with a single remote peer.</p>
 
 <p>
 <c>Type</c> indicates whether the transport process in question
-is being started for a connecting (<c>connect</c>) or listening
-(<c>accept</c>) transport.
+is being started for a connecting (<c>Type=connect</c>) or listening
+(<c>Type=accept</c>) transport.
 In the latter case, transport processes are started as required to
 accept connections from multiple peers.</p>
 
@@ -90,13 +126,12 @@ that has lead to starting of a transport process.</p>
 
 <p>
 <c>Svc</c> contains the capabilities passed to &mod_start_service; and
-&mod_add_transport;,
-values passed to the latter overriding those passed to the former.</p>
+&mod_add_transport;, values passed to the latter overriding those
+passed to the former.</p>
 
 <p>
 <c>Config</c> is as passed in <c>transport_config</c> tuple in the
-&mod_transport_opt;
-list passed to &mod_add_transport;.</p>
+&mod_transport_opt; list passed to &mod_add_transport;.</p>
 
 <p>
 The start function should use the <c>Host-IP-Address</c> list and/or
@@ -114,13 +149,13 @@ it dies.
 It should not link to the parent.
 It should exit if its transport connection with its peer is lost.</p>
 
-<marker id="MESSAGES"/>
 </desc>
 </func>
 
 </funcs>
 
 <!-- ===================================================================== -->
+<marker id="MESSAGES"/>
 
 <section>
 <title>MESSAGES</title>
@@ -130,19 +165,15 @@ All messages sent over the transport interface are of the
 form <c>{diameter, term()}</c>.</p>
 
 <p>
-A transport process can expect the following messages from
-diameter.</p>
+A transport process can expect messages of the following types from
+its parent.</p>
 
 <taglist>
 
-<tag><c>{diameter, {send, Packet}}</c></tag>
+<tag><c>{diameter, {send, &message;}}</c></tag>
 <item>
 <p>
-An outbound Diameter message.
-<c>Packet</c> can be either binary() (the message to be sent)
-or a <c>#diameter_packet{}</c> record whose <c>transport_data</c>
-field contains a value other than undefined and whose <c>bin</c> field
-contains the binary to send.</p>
+An outbound Diameter message.</p>
 </item>
 
 <tag><c>{diameter, {close, Pid}}</c></tag>
@@ -185,7 +216,7 @@ TLS.</p>
 </taglist>
 
 <p>
-A transport process should send the following messages
+A transport process should send messages of the following types
 to its parent.</p>
 
 <taglist>
@@ -208,19 +239,10 @@ Not sent if the transport process has <c>Type=accept</c>.
 endpoint to which the transport has connected.</p>
 </item>
 
-<tag><c>{diameter, {recv, Packet}}</c></tag>
+<tag><c>{diameter, {recv, &message;}}</c></tag>
 <item>
 <p>
-An inbound Diameter message.
-<c>Packet</c> can be either binary() (the received message)
-or a <c>#diameter_packet{}</c> record
-whose <c>bin</c> field contains the received binary().
-Any value (other than <c>undefined</c>) set in
-the <c>transport_data</c> field will be passed back with a
-corresponding answer message in the case that the inbound message is a
-request unless the sender sets another value.
-How <c>transport_data</c> is used/interpreted is up to the
-transport module.</p>
+An inbound Diameter message.</p>
 </item>
 
 <tag><c>{diameter, {tls, Ref}}</c></tag>
diff --git a/lib/diameter/doc/src/files.mk b/lib/diameter/doc/src/files.mk
index 89ec1031e6..00ced3d91e 100644
--- a/lib/diameter/doc/src/files.mk
+++ b/lib/diameter/doc/src/files.mk
@@ -26,6 +26,8 @@ XML_REF1_FILES = \
 XML_REF3_FILES = \
 	diameter.xml \
 	diameter_app.xml \
+	diameter_codec.xml \
+	diameter_make.xml \
 	diameter_transport.xml \
 	diameter_tcp.xml \
 	diameter_sctp.xml
diff --git a/lib/diameter/doc/src/notes.xml b/lib/diameter/doc/src/notes.xml
index b89d84a4f6..7f3cdab075 100644
--- a/lib/diameter/doc/src/notes.xml
+++ b/lib/diameter/doc/src/notes.xml
@@ -428,7 +428,7 @@ Known issues or limitations:</p>
 Some agent-related functionality is not entirely complete.
 In particular, support for proxy agents, that advertise specific
 Diameter applications but otherwise relay messages in much the same
-way as relay agents (for which a &handle_request;
+way as relay agents (for which a handle_request
 callback can return a <c>relay</c> tuple), will be completed in an
 upcoming release.
 There may also be more explicit support for redirect agents, although
@@ -460,7 +460,7 @@ could likely be expanded upon.</p>
 
 <item>
 <p>
-The function &service_info;
+The function diameter:service_info/2
 can be used to retrieve information about a started service
 (statistics, information about connected peers, etc) but
 this is not yet documented and both the input and output may change
diff --git a/lib/diameter/doc/src/ref_man.xml b/lib/diameter/doc/src/ref_man.xml
index 137ce79094..4b99fe716d 100644
--- a/lib/diameter/doc/src/ref_man.xml
+++ b/lib/diameter/doc/src/ref_man.xml
@@ -6,6 +6,7 @@
 <header>
 <copyright>
 <year>2011</year>
+<year>2012</year>
 <holder>Ericsson AB. All Rights Reserved.</holder>
 </copyright>
 <legalnotice>
@@ -40,7 +41,9 @@ applications on top of the Diameter protocol. </p>
 <xi:include href="diameter.xml"/>
 <xi:include href="diameter_compile.xml"/>
 <xi:include href="diameter_app.xml"/>
+<xi:include href="diameter_codec.xml"/>
 <xi:include href="diameter_dict.xml"/>
+<xi:include href="diameter_make.xml"/>
 <xi:include href="diameter_transport.xml"/>
 <xi:include href="diameter_tcp.xml"/>
 <xi:include href="diameter_sctp.xml"/>
diff --git a/lib/diameter/doc/src/seealso.ent b/lib/diameter/doc/src/seealso.ent
index 6f67630220..4647c42f85 100644
--- a/lib/diameter/doc/src/seealso.ent
+++ b/lib/diameter/doc/src/seealso.ent
@@ -32,6 +32,8 @@ significant.
 
 -->
 
+<!ENTITY the_rfc 'RFC 6733'>
+
 <!-- diameter -->
 
 <!ENTITY mod_add_transport '<seealso marker="diameter#add_transport-2">diameter:add_transport/2</seealso>'>
@@ -77,12 +79,21 @@ significant.
 <!ENTITY app_prepare_request '<seealso marker="diameter_app#Mod:prepare_request-3">prepare_request/3</seealso>'>
 
 <!ENTITY app_capabilities '<seealso marker="diameter_app#capabilities">diameter_app:capabilities()</seealso>'>
-<!ENTITY app_message '<seealso marker="diameter_app#message">diameter_app:message()</seealso>'>
-<!ENTITY app_packet '<seealso marker="diameter_app#packet">diameter_app:packet()</seealso>'>
 <!ENTITY app_peer '<seealso marker="diameter_app#peer">diameter_app:peer()</seealso>'>
 <!ENTITY app_peer_ref '<seealso marker="diameter_app#peer_ref">diameter_app:peer_ref()</seealso>'>
 <!ENTITY app_state '<seealso marker="diameter_app#state">diameter_app:state()</seealso>'>
 
+<!-- diameter_codec -->
+
+<!ENTITY codec_encode '<seealso marker="diameter_codec#encode-2">diameter_codec:encode/2</seealso>'>
+<!ENTITY codec_decode '<seealso marker="diameter_codec#decode-2">diameter_codec:decode/2</seealso>'>
+
+<!ENTITY codec_avp '<seealso marker="diameter_codec#avp">diameter_codec:avp()</seealso>'>
+<!ENTITY codec_header '<seealso marker="diameter_codec#header">diameter_codec:header()</seealso>'>
+<!ENTITY codec_dictionary '<seealso marker="diameter_codec#dictionary">diameter_codec:dictionary()</seealso>'>
+<!ENTITY codec_message '<seealso marker="diameter_codec#message">diameter_codec:message()</seealso>'>
+<!ENTITY codec_packet '<seealso marker="diameter_codec#packet">diameter_codec:packet()</seealso>'>
+
 <!-- diameter_dict -->
 
 <!ENTITY dict_data_types '<seealso marker="diameter_dict#DATA_TYPES">diameter_dict(4)</seealso>'>
@@ -95,6 +106,14 @@ significant.
 <!ENTITY dict_UTF8String '<seealso marker="diameter_dict#DATA_TYPES">UTF8String()</seealso>'>
 <!ENTITY dict_Unsigned32 '<seealso marker="diameter_dict#DATA_TYPES">Unsigned32()</seealso>'>
 
+<!ENTITY dict_name '<seealso marker="diameter_dict#name">@name</seealso>'>
+<!ENTITY dict_prefix '<seealso marker="diameter_dict#prefix">@prefix</seealso>'>
+<!ENTITY dict_inherits '<seealso marker="diameter_dict#inherits">@inherits</seealso>'>
+
+<!-- diameter_make -->
+
+<!ENTITY make_codec '<seealso marker="diameter_make#codec-2">diameter_make:codec/2</seealso>'>
+
 <!-- diameter_transport -->
 
 <!ENTITY transport_start
@@ -105,8 +124,9 @@ significant.
 <!ENTITY man_compile '<seealso marker="diameterc">diameterc(1)</seealso>'>
 <!ENTITY man_main '<seealso marker="diameter">diameter(3)</seealso>'>
 <!ENTITY man_app '<seealso marker="diameter_app">diameter_app(3)</seealso>'>
+<!ENTITY man_codec '<seealso marker="diameter_codec">diameter_codec(3)</seealso>'>
 <!ENTITY man_dict '<seealso marker="diameter_dict">diameter_dict(4)</seealso>'>
-<!ENTITY man_transport
-   '<seealso marker="diameter_transport">diameter_transport(3)</seealso>'>
+<!ENTITY man_make '<seealso marker="diameter_make">diameter_make(3)</seealso>'>
+<!ENTITY man_transport '<seealso marker="diameter_transport">diameter_transport(3)</seealso>'>
 <!ENTITY man_sctp '<seealso marker="diameter_sctp">diameter_sctp(3)</seealso>'>
 <!ENTITY man_tcp  '<seealso marker="diameter_tcp">diameter_tcp(3)</seealso>'>
diff --git a/lib/diameter/doc/standard/draft-ietf-dime-capablities-update-07.txt b/lib/diameter/doc/standard/draft-ietf-dime-capablities-update-07.txt
deleted file mode 100644
index bb7ec2d08c..0000000000
--- a/lib/diameter/doc/standard/draft-ietf-dime-capablities-update-07.txt
+++ /dev/null
@@ -1,392 +0,0 @@
-

-

-

-Network Working Group                                            K. Jiao

-Internet-Draft                                                    Huawei

-Intended status: Standards Track                                 G. Zorn

-Expires: April 27, 2011                                      Network Zen

-                                                        October 24, 2010

-

-

-              The Diameter Capabilities Update Application

-                 draft-ietf-dime-capablities-update-07

-

-Abstract

-

-   This document defines a new Diameter application and associated

-   command codes.  The Capabilities Update application is intended to

-   allow the dynamic update of certain Diameter peer capabilities while

-   the peer-to-peer connection is in the open state.

-

-Status of this Memo

-

-   This Internet-Draft is submitted in full conformance with the

-   provisions of BCP 78 and BCP 79.

-

-   Internet-Drafts are working documents of the Internet Engineering

-   Task Force (IETF).  Note that other groups may also distribute

-   working documents as Internet-Drafts.  The list of current Internet-

-   Drafts is at http://datatracker.ietf.org/drafts/current/.

-

-   Internet-Drafts are draft documents valid for a maximum of six months

-   and may be updated, replaced, or obsoleted by other documents at any

-   time.  It is inappropriate to use Internet-Drafts as reference

-   material or to cite them other than as "work in progress."

-

-   This Internet-Draft will expire on April 27, 2011.

-

-Copyright Notice

-

-   Copyright (c) 2010 IETF Trust and the persons identified as the

-   document authors.  All rights reserved.

-

-   This document is subject to BCP 78 and the IETF Trust's Legal

-   Provisions Relating to IETF Documents

-   (http://trustee.ietf.org/license-info) in effect on the date of

-   publication of this document.  Please review these documents

-   carefully, as they describe your rights and restrictions with respect

-   to this document.  Code Components extracted from this document must

-   include Simplified BSD License text as described in Section 4.e of

-   the Trust Legal Provisions and are provided without warranty as

-   described in the Simplified BSD License.

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 1]

-

-Internet-Draft        Diameter Capabilities Update          October 2010

-

-

-Table of Contents

-

-   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3

-   2.  Specification of Requirements . . . . . . . . . . . . . . . . . 3

-   3.  Diameter Protocol Considerations  . . . . . . . . . . . . . . . 3

-   4.  Capabilities Update . . . . . . . . . . . . . . . . . . . . . . 3

-     4.1.  Command-Code Values . . . . . . . . . . . . . . . . . . . . 4

-       4.1.1.  Capabilities-Update-Request . . . . . . . . . . . . . . 5

-       4.1.2.  Capabilities-Update-Answer  . . . . . . . . . . . . . . 5

-   5.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6

-   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6

-     6.1.  Application Identifier  . . . . . . . . . . . . . . . . . . 6

-     6.2.  Command Codes . . . . . . . . . . . . . . . . . . . . . . . 6

-   7.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . 6

-   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 6

-   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 6

-     9.1.  Normative References  . . . . . . . . . . . . . . . . . . . 6

-     9.2.  Informative References  . . . . . . . . . . . . . . . . . . 7

-   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 2]

-

-Internet-Draft        Diameter Capabilities Update          October 2010

-

-

-1.  Introduction

-

-   Capabilities exchange is an important component of the Diameter Base

-   Protocol [I-D.ietf-dime-rfc3588bis], allowing peers to exchange

-   identities and Diameter capabilities (protocol version number,

-   supported Diameter applications, security mechanisms, etc.).  As

-   defined in RFC 3588, however, the capabilities exchange process takes

-   place only once, at the inception of a transport connection between a

-   given pair of peers.  Therefore, if a peer's capabilities change (due

-   to software update, for example), the existing connection(s) must be

-   torn down (along with all of the associated user sessions) and

-   restarted before the modified capabilities can be advertised.

-

-   This document defines a new Diameter application intended to allow

-   the dynamic update of a subset of Diameter peer capabilities over an

-   existing connection.  Because the Capabilities Update application

-   specified herein operates over an existing transport connection,

-   modification of certain capabilities is prohibited.  Specifically,

-   modifying the security mechanism in use is not allowed; if the

-   security method used between a pair of peers is changed the affected

-   connection MUST be restarted.

-

-

-2.  Specification of Requirements

-

-   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

-   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this

-   document are to be interpreted as described in RFC 2119 [RFC2119].

-

-

-3.  Diameter Protocol Considerations

-

-   This section details the relationship of the Diameter Capabilities

-   Update application to the Diameter Base Protocol.

-

-   This document specifies Diameter Application-ID <TBD1>.  Diameter

-   nodes conforming to this specification MUST advertise support by

-   including the value <TBD1> in the Auth-Application-Id of the

-   Capabilities-Exchange-Request (CER) and Capabilities-Exchange-Answer

-   (CEA) commands [I-D.ietf-dime-rfc3588bis].

-

-

-4.  Capabilities Update

-

-   When the capabilities of a Diameter node conforming to this

-   specification change, it MUST notify all of the nodes with which it

-   has an open transport connection and which have also advertised

-   support for the Capabilities Update application using the

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 3]

-

-Internet-Draft        Diameter Capabilities Update          October 2010

-

-

-   Capabilities-Update-Request (CUR) message (Section 4.1.1).  This

-   message allows the update of a peer's capabilities (supported

-   Diameter applications, etc.).

-

-   A Diameter node only issues a given command to those peers that have

-   advertised support for the Diameter application that defines the

-   command; a Diameter node must cache the supported applications in

-   order to ensure that unrecognized commands and/or Attribute-Value

-   Pairs (AVPs) are not unnecessarily sent to a peer.

-

-   The receiver of the CUR MUST determine common applications by

-   computing the intersection of its own set of supported Application Id

-   against all of the application identifier AVPs (Auth-Application-Id,

-   Acct-Application-Id and Vendor-Specific- Application-Id) present in

-   the CUR.  The value of the Vendor-Id AVP in the Vendor-Specific-

-   Application-Id MUST NOT be used during computation.

-

-   If the receiver of a CUR does not have any applications in common

-   with the sender then it MUST return a Capabilities-Update-Answer

-   (CUA) (Section 4.1.2) with the Result-Code AVP set to

-   DIAMETER_NO_COMMON_APPLICATION [I-D.ietf-dime-rfc3588bis], and SHOULD

-   disconnect the transport layer connection; however, if active

-   sessions are using the connection, peers MAY delay disconnection

-   until the sessions can be redirected or gracefully terminated.  Note

-   that receiving a CUA from a peer advertising itself as a Relay (see

-   [I-D.ietf-dime-rfc3588bis], Section 2.4) MUST be interpreted as

-   having common applications with the peer.

-

-   As for CER/CEA messages, the CUR and CUA messages MUST NOT be

-   proxied, redirected or relayed.

-

-   Even though the CUR/CUA messages cannot be proxied, it is still

-   possible for an upstream agent to receive a message for which there

-   are no peers available to handle the application that corresponds to

-   the Command-Code.  This could happen if, for example, the peers are

-   too busy or down.  In such instances, the 'E' bit MUST be set in the

-   answer message with the Result-Code AVP set to

-   DIAMETER_UNABLE_TO_DELIVER to inform the downstream peer to take

-   action (e.g., re-routing requests to an alternate peer).

-

-4.1.  Command-Code Values

-

-   This section defines Command-Code [I-D.ietf-dime-rfc3588bis] values

-   that MUST be supported by all Diameter implementations conforming to

-   this specification.  The following Command Codes are defined (using

-   modified ABNF [I-D.ietf-dime-rfc3588bis]) in this document:

-   Capabilities-Update-Request (CUR, Section 4.1.1) and Capabilities-

-   Update-Answer (CUA, Section 4.1.2).

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 4]

-

-Internet-Draft        Diameter Capabilities Update          October 2010

-

-

-4.1.1.  Capabilities-Update-Request

-

-   The Capabilities-Update-Request (CUR), indicated by the Command-Code

-   set to <CUCC> and the Command Flags' 'R' bit set, is sent to update

-   local capabilities.  Upon detection of a transport failure, this

-   message MUST NOT be sent to an alternate peer.

-

-   When Diameter is run over the Stream Control Transmission Protocol

-   [RFC4960], which allows connections to span multiple interfaces and

-   multiple IP addresses, the Capabilities-Update-Request message MUST

-   contain one Host-IP-Address AVP for each potential IP address that

-   may be locally used when transmitting Diameter messages.

-

-   Message Format

-

-      <CUR> ::= < Diameter Header: <CUCC>, REQ >

-                { Origin-Host }

-                { Origin-Realm }

-             1* { Host-IP-Address }

-                { Vendor-Id }

-                { Product-Name }

-                [ Origin-State-Id ]

-              * [ Supported-Vendor-Id ]

-              * [ Auth-Application-Id ]

-              * [ Acct-Application-Id ]

-              * [ Vendor-Specific-Application-Id ]

-                [ Firmware-Revision ]

-              * [ AVP ]

-

-4.1.2.  Capabilities-Update-Answer

-

-   The Capabilities-Update-Answer, indicated by the Command-Code set to

-   <CUCC> and the Command Flags' 'R' bit cleared, is sent in response to

-   a CUR message.

-

-                   Message Format

-

-                   <CUA> ::= < Diameter Header: <CUCC> >

-                             { Origin-Host }

-                             { Origin-Realm }

-                             { Result-Code }

-                             [ Error-Message ]

-                           * [ AVP ]

-

-

-

-

-

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 5]

-

-Internet-Draft        Diameter Capabilities Update          October 2010

-

-

-5.  Security Considerations

-

-   The security considerations applicable to the Diameter Base Protocol

-   [I-D.ietf-dime-rfc3588bis] are also applicable to this document.

-

-

-6.  IANA Considerations

-

-   This section explains the criteria to be used by the IANA for

-   assignment of numbers within namespaces used within this document.

-

-6.1.  Application Identifier

-

-   This specification assigns the value <TBD1> from the Application

-   Identifiers namespace [I-D.ietf-dime-rfc3588bis].  See Section 3 for

-   the assignment of the namespace in this specification.

-

-6.2.  Command Codes

-

-   This specification assigns the value <CUCC> from the Command Codes

-   namespace [I-D.ietf-dime-rfc3588bis].  See Section 4.1 for the

-   assignment of the namespace in this specification.

-

-

-7.  Contributors

-

-   This document is based upon work done by Tina Tsou.

-

-

-8.  Acknowledgements

-

-   Thanks to Sebastien Decugis, Niklas Neumann, Subash Comerica, Lionel

-   Morand, Dan Romascanu, Dan Harkins and Ravi for helpful review and

-   discussion.

-

-

-9.  References

-

-9.1.  Normative References

-

-   [I-D.ietf-dime-rfc3588bis]

-              Fajardo, V., Arkko, J., Loughney, J., and G. Zorn,

-              "Diameter Base Protocol", draft-ietf-dime-rfc3588bis-25

-              (work in progress), September 2010.

-

-   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate

-              Requirement Levels", BCP 14, RFC 2119, March 1997.

-

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 6]

-

-Internet-Draft        Diameter Capabilities Update          October 2010

-

-

-9.2.  Informative References

-

-   [RFC4960]  Stewart, R., "Stream Control Transmission Protocol",

-              RFC 4960, September 2007.

-

-

-Authors' Addresses

-

-   Jiao Kang

-   Huawei Technologies

-   Section B1, Huawei Industrial Base

-   Bantian, Longgang District

-   Shenzhen  518129

-   P.R. China

-

-   Phone: +86 755 2878-6690

-   Email: [email protected]

-

-

-   Glen Zorn

-   Network Zen

-   227/358 Thanon Sanphawut

-   Bang Na, Bangkok  10260

-   Thailand

-

-   Phone: +66 (0) 87-040-4617

-   Email: [email protected]

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-Jiao & Zorn              Expires April 27, 2011                 [Page 7]

-

diff --git a/lib/diameter/doc/standard/draft-ietf-dime-rfc3588bis-26.txt b/lib/diameter/doc/standard/rfc6733.txt
index 87b9562f93..2f5a477347 100644
--- a/lib/diameter/doc/standard/draft-ietf-dime-rfc3588bis-26.txt
+++ b/lib/diameter/doc/standard/rfc6733.txt
@@ -1,62 +1,72 @@
 
 
 
-DIME                                                     V. Fajardo, Ed.
-Internet-Draft                                    Telcordia Technologies
-Obsoletes: 3588 (if approved)                                   J. Arkko
-Intended status: Standards Track                       Ericsson Research
-Expires: July 24, 2011                                       J. Loughney
+
+
+
+Internet Engineering Task Force (IETF)                   V. Fajardo, Ed.
+Request for Comments: 6733                        Telcordia Technologies
+Obsoletes: 3588, 5719                                           J. Arkko
+Category: Standards Track                              Ericsson Research
+ISSN: 2070-1721                                              J. Loughney
                                                    Nokia Research Center
-                                                                 G. Zorn
+                                                            G. Zorn, Ed.
                                                              Network Zen
-                                                        January 20, 2011
+                                                            October 2012
 
 
                          Diameter Base Protocol
-                   draft-ietf-dime-rfc3588bis-26.txt
 
 Abstract
 
    The Diameter base protocol is intended to provide an Authentication,
-   Authorization and Accounting (AAA) framework for applications such as
-   network access or IP mobility in both local and roaming situations.
-   This document specifies the message format, transport, error
-   reporting, accounting and security services used by all Diameter
-   applications.  The Diameter base protocol as defined in this document
-   must be supported by all Diameter implementations.
+   Authorization, and Accounting (AAA) framework for applications such
+   as network access or IP mobility in both local and roaming
+   situations.  This document specifies the message format, transport,
+   error reporting, accounting, and security services used by all
+   Diameter applications.  The Diameter base protocol as defined in this
+   document obsoletes RFC 3588 and RFC 5719, and it must be supported by
+   all new Diameter implementations.
 
-Status of this Memo
+Status of This Memo
 
-   This Internet-Draft is submitted in full conformance with the
-   provisions of BCP 78 and BCP 79.
+   This is an Internet Standards Track document.
 
-   Internet-Drafts are working documents of the Internet Engineering
-   Task Force (IETF).  Note that other groups may also distribute
-   working documents as Internet-Drafts.  The list of current Internet-
-   Drafts is at http://datatracker.ietf.org/drafts/current/.
+   This document is a product of the Internet Engineering Task Force
+   (IETF).  It represents the consensus of the IETF community.  It has
+   received public review and has been approved for publication by the
+   Internet Engineering Steering Group (IESG).  Further information on
+   Internet Standards is available in Section 2 of RFC 5741.
+
+   Information about the current status of this document, any errata,
+   and how to provide feedback on it may be obtained at
+   http://www.rfc-editor.org/info/rfc6733.
 
-   Internet-Drafts are draft documents valid for a maximum of six months
-   and may be updated, replaced, or obsoleted by other documents at any
-   time.  It is inappropriate to use Internet-Drafts as reference
-   material or to cite them other than as "work in progress."
 
-   This Internet-Draft will expire on July 24, 2011.
 
-Copyright Notice
 
-   Copyright (c) 2011 IETF Trust and the persons identified as the
-   document authors.  All rights reserved.
 
-   This document is subject to BCP 78 and the IETF Trust's Legal
-   Provisions Relating to IETF Documents
 
 
 
-Fajardo, et al.           Expires July 24, 2011                 [Page 1]
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                    [Page 1]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+Copyright Notice
+
+   Copyright (c) 2012 IETF Trust and the persons identified as the
+   document authors.  All rights reserved.
+
+   This document is subject to BCP 78 and the IETF Trust's Legal
+   Provisions Relating to IETF Documents
    (http://trustee.ietf.org/license-info) in effect on the date of
    publication of this document.  Please review these documents
    carefully, as they describe your rights and restrictions with respect
@@ -65,256 +75,303 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the Trust Legal Provisions and are provided without warranty as
    described in the Simplified BSD License.
 
+   This document may contain material from IETF Documents or IETF
+   Contributions published or made publicly available before November
+   10, 2008.  The person(s) controlling the copyright in some of this
+   material may not have granted the IETF Trust the right to allow
+   modifications of such material outside the IETF Standards Process.
+   Without obtaining an adequate license from the person(s) controlling
+   the copyright in such materials, this document may not be modified
+   outside the IETF Standards Process, and derivative works of it may
+   not be created outside the IETF Standards Process, except to format
+   it for publication as an RFC or to translate it into languages other
+   than English.
 
 Table of Contents
 
-   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   6
-     1.1.  Diameter Protocol . . . . . . . . . . . . . . . . . . . .   8
-       1.1.1.  Description of the Document Set . . . . . . . . . . .   9
-       1.1.2.  Conventions Used in This Document . . . . . . . . . .  10
-       1.1.3.  Changes from RFC3588  . . . . . . . . . . . . . . . .  10
-     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .  12
-     1.3.  Approach to Extensibility . . . . . . . . . . . . . . . .  17
-       1.3.1.  Defining New AVP Values . . . . . . . . . . . . . . .  18
-       1.3.2.  Creating New AVPs . . . . . . . . . . . . . . . . . .  18
-       1.3.3.  Creating New Commands . . . . . . . . . . . . . . . .  18
-       1.3.4.  Creating New Diameter Applications  . . . . . . . . .  19
-   2.  Protocol Overview . . . . . . . . . . . . . . . . . . . . . .  21
-     2.1.  Transport . . . . . . . . . . . . . . . . . . . . . . . .  22
-       2.1.1.  SCTP Guidelines . . . . . . . . . . . . . . . . . . .  23
-     2.2.  Securing Diameter Messages  . . . . . . . . . . . . . . .  24
-     2.3.  Diameter Application Compliance . . . . . . . . . . . . .  24
-     2.4.  Application Identifiers . . . . . . . . . . . . . . . . .  24
-     2.5.  Connections vs. Sessions  . . . . . . . . . . . . . . . .  25
-     2.6.  Peer Table  . . . . . . . . . . . . . . . . . . . . . . .  26
-     2.7.  Routing Table . . . . . . . . . . . . . . . . . . . . . .  27
-     2.8.  Role of Diameter Agents . . . . . . . . . . . . . . . . .  28
-       2.8.1.  Relay Agents  . . . . . . . . . . . . . . . . . . . .  29
-       2.8.2.  Proxy Agents  . . . . . . . . . . . . . . . . . . . .  30
-       2.8.3.  Redirect Agents . . . . . . . . . . . . . . . . . . .  31
-       2.8.4.  Translation Agents  . . . . . . . . . . . . . . . . .  32
-     2.9.  Diameter Path Authorization . . . . . . . . . . . . . . .  33
-   3.  Diameter Header . . . . . . . . . . . . . . . . . . . . . . .  35
-     3.1.  Command Codes . . . . . . . . . . . . . . . . . . . . . .  38
-     3.2.  Command Code ABNF specification . . . . . . . . . . . . .  38
-     3.3.  Diameter Command Naming Conventions . . . . . . . . . . .  41
-   4.  Diameter AVPs . . . . . . . . . . . . . . . . . . . . . . . .  42
-     4.1.  AVP Header  . . . . . . . . . . . . . . . . . . . . . . .  42
-       4.1.1.  Optional Header Elements  . . . . . . . . . . . . . .  43
-     4.2.  Basic AVP Data Formats  . . . . . . . . . . . . . . . . .  44
-     4.3.  Derived AVP Data Formats  . . . . . . . . . . . . . . . .  45
-       4.3.1.  Common Derived AVPs . . . . . . . . . . . . . . . . .  45
-     4.4.  Grouped AVP Values  . . . . . . . . . . . . . . . . . . .  52
-
-
-
-Fajardo, et al.           Expires July 24, 2011                 [Page 2]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-       4.4.1.  Example AVP with a Grouped Data type  . . . . . . . .  53
-     4.5.  Diameter Base Protocol AVPs . . . . . . . . . . . . . . .  56
-   5.  Diameter Peers  . . . . . . . . . . . . . . . . . . . . . . .  59
-     5.1.  Peer Connections  . . . . . . . . . . . . . . . . . . . .  59
-     5.2.  Diameter Peer Discovery . . . . . . . . . . . . . . . . .  60
-     5.3.  Capabilities Exchange . . . . . . . . . . . . . . . . . .  61
-       5.3.1.  Capabilities-Exchange-Request . . . . . . . . . . . .  63
-       5.3.2.  Capabilities-Exchange-Answer  . . . . . . . . . . . .  63
-       5.3.3.  Vendor-Id AVP . . . . . . . . . . . . . . . . . . . .  64
-       5.3.4.  Firmware-Revision AVP . . . . . . . . . . . . . . . .  64
-       5.3.5.  Host-IP-Address AVP . . . . . . . . . . . . . . . . .  64
-       5.3.6.  Supported-Vendor-Id AVP . . . . . . . . . . . . . . .  65
-       5.3.7.  Product-Name AVP  . . . . . . . . . . . . . . . . . .  65
-     5.4.  Disconnecting Peer connections  . . . . . . . . . . . . .  65
-       5.4.1.  Disconnect-Peer-Request . . . . . . . . . . . . . . .  66
-       5.4.2.  Disconnect-Peer-Answer  . . . . . . . . . . . . . . .  66
-       5.4.3.  Disconnect-Cause AVP  . . . . . . . . . . . . . . . .  66
-     5.5.  Transport Failure Detection . . . . . . . . . . . . . . .  67
-       5.5.1.  Device-Watchdog-Request . . . . . . . . . . . . . . .  67
-       5.5.2.  Device-Watchdog-Answer  . . . . . . . . . . . . . . .  67
-       5.5.3.  Transport Failure Algorithm . . . . . . . . . . . . .  68
-       5.5.4.  Failover and Failback Procedures  . . . . . . . . . .  68
-     5.6.  Peer State Machine  . . . . . . . . . . . . . . . . . . .  69
-       5.6.1.  Incoming connections  . . . . . . . . . . . . . . . .  71
-       5.6.2.  Events  . . . . . . . . . . . . . . . . . . . . . . .  72
-       5.6.3.  Actions . . . . . . . . . . . . . . . . . . . . . . .  73
-       5.6.4.  The Election Process  . . . . . . . . . . . . . . . .  75
-   6.  Diameter message processing . . . . . . . . . . . . . . . . .  76
-     6.1.  Diameter Request Routing Overview . . . . . . . . . . . .  76
-       6.1.1.  Originating a Request . . . . . . . . . . . . . . . .  77
-       6.1.2.  Sending a Request . . . . . . . . . . . . . . . . . .  77
-       6.1.3.  Receiving Requests  . . . . . . . . . . . . . . . . .  78
-       6.1.4.  Processing Local Requests . . . . . . . . . . . . . .  78
-       6.1.5.  Request Forwarding  . . . . . . . . . . . . . . . . .  78
-       6.1.6.  Request Routing . . . . . . . . . . . . . . . . . . .  78
-       6.1.7.  Predictive Loop Avoidance . . . . . . . . . . . . . .  79
-       6.1.8.  Redirecting Requests  . . . . . . . . . . . . . . . .  79
-       6.1.9.  Relaying and Proxying Requests  . . . . . . . . . . .  80
-     6.2.  Diameter Answer Processing  . . . . . . . . . . . . . . .  82
-       6.2.1.  Processing received Answers . . . . . . . . . . . . .  82
-       6.2.2.  Relaying and Proxying Answers . . . . . . . . . . . .  82
-     6.3.  Origin-Host AVP . . . . . . . . . . . . . . . . . . . . .  83
-     6.4.  Origin-Realm AVP  . . . . . . . . . . . . . . . . . . . .  83
-     6.5.  Destination-Host AVP  . . . . . . . . . . . . . . . . . .  83
-     6.6.  Destination-Realm AVP . . . . . . . . . . . . . . . . . .  84
-     6.7.  Routing AVPs  . . . . . . . . . . . . . . . . . . . . . .  84
-       6.7.1.  Route-Record AVP  . . . . . . . . . . . . . . . . . .  84
-       6.7.2.  Proxy-Info AVP  . . . . . . . . . . . . . . . . . . .  84
-
-
-
-Fajardo, et al.           Expires July 24, 2011                 [Page 3]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-       6.7.3.  Proxy-Host AVP  . . . . . . . . . . . . . . . . . . .  85
-       6.7.4.  Proxy-State AVP . . . . . . . . . . . . . . . . . . .  85
-     6.8.  Auth-Application-Id AVP . . . . . . . . . . . . . . . . .  85
-     6.9.  Acct-Application-Id AVP . . . . . . . . . . . . . . . . .  85
-     6.10. Inband-Security-Id AVP  . . . . . . . . . . . . . . . . .  85
-     6.11. Vendor-Specific-Application-Id AVP  . . . . . . . . . . .  86
-     6.12. Redirect-Host AVP . . . . . . . . . . . . . . . . . . . .  87
-     6.13. Redirect-Host-Usage AVP . . . . . . . . . . . . . . . . .  87
-     6.14. Redirect-Max-Cache-Time AVP . . . . . . . . . . . . . . .  88
-   7.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .  90
-     7.1.  Result-Code AVP . . . . . . . . . . . . . . . . . . . . .  92
-       7.1.1.  Informational . . . . . . . . . . . . . . . . . . . .  92
-       7.1.2.  Success . . . . . . . . . . . . . . . . . . . . . . .  93
-       7.1.3.  Protocol Errors . . . . . . . . . . . . . . . . . . .  93
-       7.1.4.  Transient Failures  . . . . . . . . . . . . . . . . .  94
-       7.1.5.  Permanent Failures  . . . . . . . . . . . . . . . . .  95
-     7.2.  Error Bit . . . . . . . . . . . . . . . . . . . . . . . .  98
-     7.3.  Error-Message AVP . . . . . . . . . . . . . . . . . . . .  99
-     7.4.  Error-Reporting-Host AVP  . . . . . . . . . . . . . . . .  99
-     7.5.  Failed-AVP AVP  . . . . . . . . . . . . . . . . . . . . .  99
-     7.6.  Experimental-Result AVP . . . . . . . . . . . . . . . . . 100
-     7.7.  Experimental-Result-Code AVP  . . . . . . . . . . . . . . 100
-   8.  Diameter User Sessions  . . . . . . . . . . . . . . . . . . . 101
-     8.1.  Authorization Session State Machine . . . . . . . . . . . 102
-     8.2.  Accounting Session State Machine  . . . . . . . . . . . . 107
-     8.3.  Server-Initiated Re-Auth  . . . . . . . . . . . . . . . . 112
-       8.3.1.  Re-Auth-Request . . . . . . . . . . . . . . . . . . . 112
-       8.3.2.  Re-Auth-Answer  . . . . . . . . . . . . . . . . . . . 113
-     8.4.  Session Termination . . . . . . . . . . . . . . . . . . . 114
-       8.4.1.  Session-Termination-Request . . . . . . . . . . . . . 115
-       8.4.2.  Session-Termination-Answer  . . . . . . . . . . . . . 115
-     8.5.  Aborting a Session  . . . . . . . . . . . . . . . . . . . 116
-       8.5.1.  Abort-Session-Request . . . . . . . . . . . . . . . . 116
-       8.5.2.  Abort-Session-Answer  . . . . . . . . . . . . . . . . 117
-     8.6.  Inferring Session Termination from Origin-State-Id  . . . 118
-     8.7.  Auth-Request-Type AVP . . . . . . . . . . . . . . . . . . 118
-     8.8.  Session-Id AVP  . . . . . . . . . . . . . . . . . . . . . 119
-     8.9.  Authorization-Lifetime AVP  . . . . . . . . . . . . . . . 120
-     8.10. Auth-Grace-Period AVP . . . . . . . . . . . . . . . . . . 121
-     8.11. Auth-Session-State AVP  . . . . . . . . . . . . . . . . . 121
-     8.12. Re-Auth-Request-Type AVP  . . . . . . . . . . . . . . . . 121
-     8.13. Session-Timeout AVP . . . . . . . . . . . . . . . . . . . 122
-     8.14. User-Name AVP . . . . . . . . . . . . . . . . . . . . . . 122
-     8.15. Termination-Cause AVP . . . . . . . . . . . . . . . . . . 122
-     8.16. Origin-State-Id AVP . . . . . . . . . . . . . . . . . . . 124
-     8.17. Session-Binding AVP . . . . . . . . . . . . . . . . . . . 124
-     8.18. Session-Server-Failover AVP . . . . . . . . . . . . . . . 125
-     8.19. Multi-Round-Time-Out AVP  . . . . . . . . . . . . . . . . 126
-
-
-
-Fajardo, et al.           Expires July 24, 2011                 [Page 4]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-     8.20. Class AVP . . . . . . . . . . . . . . . . . . . . . . . . 126
-     8.21. Event-Timestamp AVP . . . . . . . . . . . . . . . . . . . 126
-   9.  Accounting  . . . . . . . . . . . . . . . . . . . . . . . . . 127
-     9.1.  Server Directed Model . . . . . . . . . . . . . . . . . . 127
-     9.2.  Protocol Messages . . . . . . . . . . . . . . . . . . . . 128
-     9.3.  Accounting Application Extension and Requirements . . . . 128
-     9.4.  Fault Resilience  . . . . . . . . . . . . . . . . . . . . 129
-     9.5.  Accounting Records  . . . . . . . . . . . . . . . . . . . 129
-     9.6.  Correlation of Accounting Records . . . . . . . . . . . . 130
-     9.7.  Accounting Command-Codes  . . . . . . . . . . . . . . . . 131
-       9.7.1.  Accounting-Request  . . . . . . . . . . . . . . . . . 131
-       9.7.2.  Accounting-Answer . . . . . . . . . . . . . . . . . . 132
-     9.8.  Accounting AVPs . . . . . . . . . . . . . . . . . . . . . 133
-       9.8.1.  Accounting-Record-Type AVP  . . . . . . . . . . . . . 133
-       9.8.2.  Acct-Interim-Interval AVP . . . . . . . . . . . . . . 134
-       9.8.3.  Accounting-Record-Number AVP  . . . . . . . . . . . . 135
-       9.8.4.  Acct-Session-Id AVP . . . . . . . . . . . . . . . . . 135
-       9.8.5.  Acct-Multi-Session-Id AVP . . . . . . . . . . . . . . 135
-       9.8.6.  Accounting-Sub-Session-Id AVP . . . . . . . . . . . . 135
-       9.8.7.  Accounting-Realtime-Required AVP  . . . . . . . . . . 136
-   10. AVP Occurrence Table  . . . . . . . . . . . . . . . . . . . . 137
-     10.1. Base Protocol Command AVP Table . . . . . . . . . . . . . 137
-     10.2. Accounting AVP Table  . . . . . . . . . . . . . . . . . . 138
-   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 140
-     11.1. Changes to AVP Header Allocation  . . . . . . . . . . . . 140
-     11.2. Diameter Header . . . . . . . . . . . . . . . . . . . . . 140
-     11.3. AVP Values  . . . . . . . . . . . . . . . . . . . . . . . 140
-       11.3.1. Experimental-Result-Code AVP  . . . . . . . . . . . . 140
-     11.4. Diameter TCP, SCTP, TLS/TCP and DTLS/SCTP Port Numbers  . 141
-     11.5. S-NAPTR Parameters  . . . . . . . . . . . . . . . . . . . 141
-   12. Diameter protocol related configurable parameters . . . . . . 142
-   13. Security Considerations . . . . . . . . . . . . . . . . . . . 143
-     13.1. TLS/TCP and DTLS/SCTP Usage . . . . . . . . . . . . . . . 143
-     13.2. Peer-to-Peer Considerations . . . . . . . . . . . . . . . 144
-   14. References  . . . . . . . . . . . . . . . . . . . . . . . . . 145
-     14.1. Normative References  . . . . . . . . . . . . . . . . . . 145
-     14.2. Informational References  . . . . . . . . . . . . . . . . 147
-   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . . 149
-     A.1.  RFC3588bis  . . . . . . . . . . . . . . . . . . . . . . . 149
-     A.2.  RFC3588 . . . . . . . . . . . . . . . . . . . . . . . . . 150
-   Appendix B.  S-NAPTR Example  . . . . . . . . . . . . . . . . . . 151
-   Appendix C.  Duplicate Detection  . . . . . . . . . . . . . . . . 152
-   Appendix D.  Internationalized Domain Names . . . . . . . . . . . 154
-   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . 155
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                 [Page 5]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   1. Introduction ....................................................7
+      1.1. Diameter Protocol ..........................................9
+           1.1.1. Description of the Document Set ....................10
+           1.1.2. Conventions Used in This Document ..................11
+           1.1.3. Changes from RFC 3588 ..............................11
+      1.2. Terminology ...............................................12
+      1.3. Approach to Extensibility .................................17
+           1.3.1. Defining New AVP Values ............................18
+           1.3.2. Creating New AVPs ..................................18
+           1.3.3. Creating New Commands ..............................18
+           1.3.4. Creating New Diameter Applications .................19
+   2. Protocol Overview ..............................................20
+      2.1. Transport .................................................22
+           2.1.1. SCTP Guidelines ....................................23
+      2.2. Securing Diameter Messages ................................24
+      2.3. Diameter Application Compliance ...........................24
+      2.4. Application Identifiers ...................................24
+      2.5. Connections vs. Sessions ..................................25
+      2.6. Peer Table ................................................26
+
+
+
+Fajardo, et al.              Standards Track                    [Page 2]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+      2.7. Routing Table .............................................27
+      2.8. Role of Diameter Agents ...................................28
+           2.8.1. Relay Agents .......................................30
+           2.8.2. Proxy Agents .......................................31
+           2.8.3. Redirect Agents ....................................31
+           2.8.4. Translation Agents .................................32
+      2.9. Diameter Path Authorization ...............................33
+   3. Diameter Header ................................................34
+      3.1. Command Codes .............................................37
+      3.2. Command Code Format Specification .........................38
+      3.3. Diameter Command Naming Conventions .......................40
+   4. Diameter AVPs ..................................................40
+      4.1. AVP Header ................................................41
+           4.1.1. Optional Header Elements ...........................42
+      4.2. Basic AVP Data Formats ....................................43
+      4.3. Derived AVP Data Formats ..................................44
+           4.3.1. Common Derived AVP Data Formats ....................44
+      4.4. Grouped AVP Values ........................................51
+           4.4.1. Example AVP with a Grouped Data Type ...............52
+      4.5. Diameter Base Protocol AVPs ...............................55
+   5. Diameter Peers .................................................58
+      5.1. Peer Connections ..........................................58
+      5.2. Diameter Peer Discovery ...................................59
+      5.3. Capabilities Exchange .....................................60
+           5.3.1. Capabilities-Exchange-Request ......................62
+           5.3.2. Capabilities-Exchange-Answer .......................63
+           5.3.3. Vendor-Id AVP ......................................63
+           5.3.4. Firmware-Revision AVP ..............................64
+           5.3.5. Host-IP-Address AVP ................................64
+           5.3.6. Supported-Vendor-Id AVP ............................64
+           5.3.7. Product-Name AVP ...................................64
+      5.4. Disconnecting Peer Connections ............................64
+           5.4.1. Disconnect-Peer-Request ............................65
+           5.4.2. Disconnect-Peer-Answer .............................65
+           5.4.3. Disconnect-Cause AVP ...............................66
+      5.5. Transport Failure Detection ...............................66
+           5.5.1. Device-Watchdog-Request ............................67
+           5.5.2. Device-Watchdog-Answer .............................67
+           5.5.3. Transport Failure Algorithm ........................67
+           5.5.4. Failover and Failback Procedures ...................67
+      5.6. Peer State Machine ........................................68
+           5.6.1. Incoming Connections ...............................71
+           5.6.2. Events .............................................71
+           5.6.3. Actions ............................................72
+           5.6.4. The Election Process ...............................74
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                    [Page 3]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   6. Diameter Message Processing ....................................74
+      6.1. Diameter Request Routing Overview .........................74
+           6.1.1. Originating a Request ..............................75
+           6.1.2. Sending a Request ..................................76
+           6.1.3. Receiving Requests .................................76
+           6.1.4. Processing Local Requests ..........................76
+           6.1.5. Request Forwarding .................................77
+           6.1.6. Request Routing ....................................77
+           6.1.7. Predictive Loop Avoidance ..........................77
+           6.1.8. Redirecting Requests ...............................78
+           6.1.9. Relaying and Proxying Requests .....................79
+      6.2. Diameter Answer Processing ................................80
+           6.2.1. Processing Received Answers ........................81
+           6.2.2. Relaying and Proxying Answers ......................81
+      6.3. Origin-Host AVP ...........................................81
+      6.4. Origin-Realm AVP ..........................................82
+      6.5. Destination-Host AVP ......................................82
+      6.6. Destination-Realm AVP .....................................82
+      6.7. Routing AVPs ..............................................83
+           6.7.1. Route-Record AVP ...................................83
+           6.7.2. Proxy-Info AVP .....................................83
+           6.7.3. Proxy-Host AVP .....................................83
+           6.7.4. Proxy-State AVP ....................................83
+      6.8. Auth-Application-Id AVP ...................................83
+      6.9. Acct-Application-Id AVP ...................................84
+      6.10. Inband-Security-Id AVP ...................................84
+      6.11. Vendor-Specific-Application-Id AVP .......................84
+      6.12. Redirect-Host AVP ........................................85
+      6.13. Redirect-Host-Usage AVP ..................................85
+      6.14. Redirect-Max-Cache-Time AVP ..............................87
+   7. Error Handling .................................................87
+      7.1. Result-Code AVP ...........................................89
+           7.1.1. Informational ......................................90
+           7.1.2. Success ............................................90
+           7.1.3. Protocol Errors ....................................90
+           7.1.4. Transient Failures .................................92
+           7.1.5. Permanent Failures .................................92
+      7.2. Error Bit .................................................95
+      7.3. Error-Message AVP .........................................96
+      7.4. Error-Reporting-Host AVP ..................................96
+      7.5. Failed-AVP AVP ............................................96
+      7.6. Experimental-Result AVP ...................................97
+      7.7. Experimental-Result-Code AVP ..............................97
+   8. Diameter User Sessions .........................................98
+      8.1. Authorization Session State Machine .......................99
+      8.2. Accounting Session State Machine .........................104
+
+
+
+
+
+Fajardo, et al.              Standards Track                    [Page 4]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+      8.3. Server-Initiated Re-Auth .................................110
+           8.3.1. Re-Auth-Request ...................................110
+           8.3.2. Re-Auth-Answer ....................................110
+      8.4. Session Termination ......................................111
+           8.4.1. Session-Termination-Request .......................112
+           8.4.2. Session-Termination-Answer ........................113
+      8.5. Aborting a Session .......................................113
+           8.5.1. Abort-Session-Request .............................114
+           8.5.2. Abort-Session-Answer ..............................114
+      8.6. Inferring Session Termination from Origin-State-Id .......115
+      8.7. Auth-Request-Type AVP ....................................116
+      8.8. Session-Id AVP ...........................................116
+      8.9. Authorization-Lifetime AVP ...............................117
+      8.10. Auth-Grace-Period AVP ...................................118
+      8.11. Auth-Session-State AVP ..................................118
+      8.12. Re-Auth-Request-Type AVP ................................118
+      8.13. Session-Timeout AVP .....................................119
+      8.14. User-Name AVP ...........................................119
+      8.15. Termination-Cause AVP ...................................120
+      8.16. Origin-State-Id AVP .....................................120
+      8.17. Session-Binding AVP .....................................120
+      8.18. Session-Server-Failover AVP .............................121
+      8.19. Multi-Round-Time-Out AVP ................................122
+      8.20. Class AVP ...............................................122
+      8.21. Event-Timestamp AVP .....................................122
+   9. Accounting ....................................................123
+      9.1. Server Directed Model ....................................123
+      9.2. Protocol Messages ........................................124
+      9.3. Accounting Application Extension and Requirements ........124
+      9.4. Fault Resilience .........................................125
+      9.5. Accounting Records .......................................125
+      9.6. Correlation of Accounting Records ........................126
+      9.7. Accounting Command Codes .................................127
+           9.7.1. Accounting-Request ................................127
+           9.7.2. Accounting-Answer .................................128
+      9.8. Accounting AVPs ..........................................129
+           9.8.1. Accounting-Record-Type AVP ........................129
+           9.8.2. Acct-Interim-Interval AVP .........................130
+           9.8.3. Accounting-Record-Number AVP ......................131
+           9.8.4. Acct-Session-Id AVP ...............................131
+           9.8.5. Acct-Multi-Session-Id AVP .........................131
+           9.8.6. Accounting-Sub-Session-Id AVP .....................131
+           9.8.7. Accounting-Realtime-Required AVP ..................132
+   10. AVP Occurrence Tables ........................................132
+      10.1. Base Protocol Command AVP Table .........................133
+      10.2. Accounting AVP Table ....................................134
+
+
+
+
+
+Fajardo, et al.              Standards Track                    [Page 5]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   11. IANA Considerations ..........................................135
+      11.1. AVP Header ..............................................135
+           11.1.1. AVP Codes ........................................136
+           11.1.2. AVP Flags ........................................136
+      11.2. Diameter Header .........................................136
+           11.2.1. Command Codes ....................................136
+           11.2.2. Command Flags ....................................137
+      11.3. AVP Values ..............................................137
+           11.3.1. Experimental-Result-Code AVP .....................137
+           11.3.2. Result-Code AVP Values ...........................137
+           11.3.3. Accounting-Record-Type AVP Values ................137
+           11.3.4. Termination-Cause AVP Values .....................137
+           11.3.5. Redirect-Host-Usage AVP Values ...................137
+           11.3.6. Session-Server-Failover AVP Values ...............137
+           11.3.7. Session-Binding AVP Values .......................137
+           11.3.8. Disconnect-Cause AVP Values ......................138
+           11.3.9. Auth-Request-Type AVP Values .....................138
+           11.3.10. Auth-Session-State AVP Values ...................138
+           11.3.11. Re-Auth-Request-Type AVP Values .................138
+           11.3.12. Accounting-Realtime-Required AVP Values .........138
+           11.3.13. Inband-Security-Id AVP (code 299) ...............138
+      11.4. _diameters Service Name and Port Number Registration ....138
+      11.5. SCTP Payload Protocol Identifiers .......................139
+      11.6. S-NAPTR Parameters ......................................139
+   12. Diameter Protocol-Related Configurable Parameters ............139
+   13. Security Considerations ......................................140
+      13.1. TLS/TCP and DTLS/SCTP Usage .............................140
+      13.2. Peer-to-Peer Considerations .............................141
+      13.3. AVP Considerations ......................................141
+   14. References ...................................................142
+      14.1. Normative References ....................................142
+      14.2. Informative References ..................................144
+   Appendix A. Acknowledgements .....................................147
+     A.1. This Document .............................................147
+     A.2. RFC 3588 ..................................................148
+   Appendix B. S-NAPTR Example ......................................148
+   Appendix C. Duplicate Detection ..................................149
+   Appendix D. Internationalized Domain Names .......................151
+
+
+
+
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                    [Page 6]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 1.  Introduction
 
-   Authentication, Authorization and Accounting (AAA) protocols such as
+   Authentication, Authorization, and Accounting (AAA) protocols such as
    TACACS [RFC1492] and RADIUS [RFC2865] were initially deployed to
    provide dial-up PPP [RFC1661] and terminal server access.  Over time,
    AAA support was needed on many new access technologies, the scale and
    complexity of AAA networks grew, and AAA was also used on new
-   applications (such as voice over IP).  This lead to new demands on
-   AAA protocols.
+   applications (such as voice over IP).  This led to new demands on AAA
+   protocols.
 
    Network access requirements for AAA protocols are summarized in
-   [RFC2989].  These include:
-
+   Aboba, et al. [RFC2989].  These include:
 
    Failover
 
-      [RFC2865] does not define failover mechanisms, and as a result,
+      [RFC2865] does not define failover mechanisms and, as a result,
       failover behavior differs between implementations.  In order to
       provide well-defined failover behavior, Diameter supports
-      application-layer acknowledgements, and defines failover
-      algorithms and the associated state machine.  This is described in
-      Section 5.5 and [RFC3539].
+      application-layer acknowledgements and defines failover algorithms
+      and the associated state machine.
 
    Transmission-level security
 
-      [RFC2865] defines an application-layer authentication and
-      integrity scheme that is required only for use with Response
+      RADIUS [RFC2865] defines an application-layer authentication and
+      integrity scheme that is required only for use with response
       packets.  While [RFC2869] defines an additional authentication and
       integrity mechanism, use is only required during Extensible
-      Authentication Protocol (EAP) sessions.  While attribute-hiding is
-      supported, [RFC2865] does not provide support for per-packet
-      confidentiality.  In accounting, [RFC2866] assumes that replay
-      protection is provided by the backend billing server, rather than
-      within the protocol itself.
+      Authentication Protocol (EAP) [RFC3748] sessions.  While attribute
+      hiding is supported, [RFC2865] does not provide support for per-
+      packet confidentiality.  In accounting, [RFC2866] assumes that
+      replay protection is provided by the backend billing server rather
+      than within the protocol itself.
 
       While [RFC3162] defines the use of IPsec with RADIUS, support for
       IPsec is not required.  In order to provide universal support for
@@ -322,50 +379,48 @@ Internet-Draft           Diameter Base Protocol             January 2011
       domain AAA deployments, Diameter provides support for TLS/TCP and
       DTLS/SCTP.  Security is discussed in Section 13.
 
-
    Reliable transport
 
-
       RADIUS runs over UDP, and does not define retransmission behavior;
       as a result, reliability varies between implementations.  As
       described in [RFC2975], this is a major issue in accounting, where
+      packet loss may translate directly into revenue loss.  In order to
 
 
 
-Fajardo, et al.           Expires July 24, 2011                 [Page 6]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-      packet loss may translate directly into revenue loss.  In order to
-      provide well defined transport behavior, Diameter runs over
-      reliable transport mechanisms (TCP, SCTP) as defined in [RFC3539].
 
+Fajardo, et al.              Standards Track                    [Page 7]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   Agent support
 
-      [RFC2865] does not provide for explicit support for agents,
-      including Proxies, Redirects and Relays.  Since the expected
-      behavior is not defined, it varies between implementations.
-      Diameter defines agent behavior explicitly; this is described in
-      Section 2.8.
+      provide well-defined transport behavior, Diameter runs over
+      reliable transport mechanisms (TCP, Stream Control Transmission
+      Protocol (SCTP)) as defined in [RFC3539].
+
+   Agent support
 
+      RADIUS does not provide for explicit support for agents, including
+      proxies, redirects, and relays.  Since the expected behavior is
+      not defined, it varies between implementations.  Diameter defines
+      agent behavior explicitly; this is described in Section 2.8.
 
    Server-initiated messages
 
-      While RADIUS server-initiated messages are defined in [RFC5176],
+      While server-initiated messages are defined in RADIUS [RFC5176],
       support is optional.  This makes it difficult to implement
       features such as unsolicited disconnect or re-authentication/
       re-authorization on demand across a heterogeneous deployment.  To
-      tackle this issue, support for server-initiated messages is
+      address this issue, support for server-initiated messages is
       mandatory in Diameter.
 
-
    Transition support
 
       While Diameter does not share a common protocol data unit (PDU)
       with RADIUS, considerable effort has been expended in enabling
-      backward compatibility with RADIUS, so that the two protocols may
+      backward compatibility with RADIUS so that the two protocols may
       be deployed in the same network.  Initially, it is expected that
       Diameter will be deployed within new network devices, as well as
       within gateways enabling communication between legacy RADIUS
@@ -373,9 +428,8 @@ Internet-Draft           Diameter Base Protocol             January 2011
       support to be added to legacy networks, by addition of a gateway
       or server speaking both RADIUS and Diameter.
 
-      In addition to addressing the above requirements, Diameter also
-      provides support for the following:
-
+   In addition to addressing the above requirements, Diameter also
+   provides support for the following:
 
    Capability negotiation
 
@@ -383,19 +437,19 @@ Internet-Draft           Diameter Base Protocol             January 2011
       a mandatory/non-mandatory flag for attributes.  Since RADIUS
       clients and servers are not aware of each other's capabilities,
       they may not be able to successfully negotiate a mutually
-      acceptable service, or in some cases, even be aware of what
+      acceptable service or, in some cases, even be aware of what
       service has been implemented.  Diameter includes support for error
+      handling (Section 7), capability negotiation (Section 5.3), and
+      mandatory/non-mandatory Attribute-Value Pairs (AVPs)
+      (Section 4.1).
 
 
 
-Fajardo, et al.           Expires July 24, 2011                 [Page 7]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-      handling (Section 7), capability negotiation (Section 5.3), and
-      mandatory/non-mandatory Attribute-Value Pairs (AVPs) (Section
-      4.1).
+Fajardo, et al.              Standards Track                    [Page 8]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Peer discovery and configuration
@@ -403,7 +457,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
       RADIUS implementations typically require that the name or address
       of servers or clients be manually configured, along with the
       corresponding shared secrets.  This results in a large
-      administrative burden, and creates the temptation to reuse the
+      administrative burden and creates the temptation to reuse the
       RADIUS shared secret, which can result in major security
       vulnerabilities if the Request Authenticator is not globally and
       temporally unique as required in [RFC2865].  Through DNS, Diameter
@@ -411,7 +465,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
       of dynamic session keys is enabled via transmission-level
       security.
 
-
    Over time, the capabilities of Network Access Server (NAS) devices
    have increased substantially.  As a result, while Diameter is a
    considerably more sophisticated protocol than RADIUS, it remains
@@ -427,42 +480,41 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    o  Error notification
 
-   o  Extensibility, through addition of new applications, commands and
-      AVPs (required in [RFC2989]).
+   o  Extensibility, required in [RFC2989], through addition of new
+      applications, commands, and AVPs
 
-   o  Basic services necessary for applications, such as handling of
+   o  Basic services necessary for applications, such as the handling of
       user sessions or accounting
 
    All data delivered by the protocol is in the form of AVPs.  Some of
    these AVP values are used by the Diameter protocol itself, while
    others deliver data associated with particular applications that
    employ Diameter.  AVPs may be arbitrarily added to Diameter messages,
-   the only restriction being that the Augmented Backus-Naur Form (ABNF,
-   [RFC5234]) Command Code syntax specification (Section 3.2) is
-   satisfied.  AVPs are used by the base Diameter protocol to support
-   the following required features:
+   the only restriction being that the Command Code Format (CCF)
+   specification (Section 3.2) be satisfied.  AVPs are used by the base
+   Diameter protocol to support the following required features:
 
+   o  Transporting of user authentication information, for the purposes
+      of enabling the Diameter server to authenticate the user
 
+   o  Transporting of service-specific authorization information,
+      between client and servers, allowing the peers to decide whether a
+      user's access request should be granted
 
-Fajardo, et al.           Expires July 24, 2011                 [Page 8]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-   o  Transporting of user authentication information, for the purposes
-      of enabling the Diameter server to authenticate the user.
+Fajardo, et al.              Standards Track                    [Page 9]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   o  Transporting of service-specific authorization information,
-      between client and servers, allowing the peers to decide whether a
-      user's access request should be granted.
 
    o  Exchanging resource usage information, which may be used for
       accounting purposes, capacity planning, etc.
 
-   o  Routing, relaying, proxying and redirecting of Diameter messages
-      through a server hierarchy.
+   o  Routing, relaying, proxying, and redirecting of Diameter messages
+      through a server hierarchy
 
-   The Diameter base protocol satisfies the minimum requirements for an
+   The Diameter base protocol satisfies the minimum requirements for a
    AAA protocol, as specified by [RFC2989].  The base protocol may be
    used by itself for accounting purposes only, or it may be used with a
    Diameter application, such as Mobile IPv4 [RFC4004], or network
@@ -473,16 +525,16 @@ Internet-Draft           Diameter Base Protocol             January 2011
    many applications might provide functionality not provided by
    Diameter.  Therefore, it is imperative that the designers of new
    applications understand their requirements before using Diameter.
-   See Section 2.4 for more information on Diameter applications.
+   See Section 1.3.4 for more information on Diameter applications.
 
    Any node can initiate a request.  In that sense, Diameter is a peer-
-   to-peer protocol.  In this document, a Diameter Client is a device at
+   to-peer protocol.  In this document, a Diameter client is a device at
    the edge of the network that performs access control, such as a
    Network Access Server (NAS) or a Foreign Agent (FA).  A Diameter
    client generates Diameter messages to request authentication,
    authorization, and accounting services for the user.  A Diameter
    agent is a node that does not provide local user authentication or
-   authorization services; agents include proxies, redirects and relay
+   authorization services; agents include proxies, redirects, and relay
    agents.  A Diameter server performs authentication and/or
    authorization of the user.  A Diameter node may act as an agent for
    certain requests while acting as a server for others.
@@ -494,33 +546,33 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    The Diameter specification consists of an updated version of the base
    protocol specification (this document) and the Transport Profile
-   [RFC3539].  This document obsoletes RFC 3588.  A summary of the base
-   protocol updates included in this document can be found in
-   Section 1.1.3.
-
-
-
-Fajardo, et al.           Expires July 24, 2011                 [Page 9]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+   [RFC3539].  This document obsoletes both RFC 3588 and RFC 5719.  A
+   summary of the base protocol updates included in this document can be
+   found in Section 1.1.3.
 
    This document defines the base protocol specification for AAA, which
    includes support for accounting.  There are also a myriad of
    applications documents describing applications that use this base
-   specification for Authentication, Authorization and Accounting.
+   specification for Authentication, Authorization, and Accounting.
    These application documents specify how to use the Diameter protocol
    within the context of their application.
 
+
+
+Fajardo, et al.              Standards Track                   [Page 10]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    The Transport Profile document [RFC3539] discusses transport layer
    issues that arise with AAA protocols and recommendations on how to
    overcome these issues.  This document also defines the Diameter
    failover algorithm and state machine.
 
-   Clarifications on the Routing of Diameter Request based on Username
-   and the Realm [RFC5729] defines specific behavior on how to route
-   request based on the content of the User-Name AVP (Attribute Value
-   Pair).
+   "Clarifications on the Routing of Diameter Request Based on the
+   Username and the Realm" [RFC5729] defines specific behavior on how to
+   route requests based on the content of the User-Name AVP (Attribute
+   Value Pair).
 
 1.1.2.  Conventions Used in This Document
 
@@ -528,100 +580,100 @@ Internet-Draft           Diameter Base Protocol             January 2011
    "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
    document are to be interpreted as described in [RFC2119].
 
-1.1.3.  Changes from RFC3588
+1.1.3.  Changes from RFC 3588
 
    This document obsoletes RFC 3588 but is fully backward compatible
    with that document.  The changes introduced in this document focus on
-   fixing issues that have surfaced during implementation of [RFC3588].
-   An overview of some the major changes are given below.
-
-   o  Deprecated the use of Inband-Security AVP for negotiating
-      transport layer security.  It has been generally considered that
-      bootstrapping of TLS via Inband-Security AVP creates certain
-      security risk because it does not completely protect the
-      information carried in the CER (Capabilities Exchange Request)/CEA
-      (Capabilities Exchange Answer).  This version of Diameter adopted
-      a common approach of defining a well-known secured port that peers
-      should use when communicating via TLS/TCP and DTLS/SCTP.  This new
-      approach augments the existing Inband-Security negotiation but
-      does not completely replace it.  The old method is kept for
-      backwards compatibility reasons.
+   fixing issues that have surfaced during the implementation of
+   Diameter (RFC 3588).  An overview of some the major changes are given
+   below.
+
+   o  Deprecated the use of the Inband-Security AVP for negotiating
+      Transport Layer Security (TLS) [RFC5246].  It has been generally
+      considered that bootstrapping of TLS via Inband-Security AVP
+      creates certain security risks because it does not completely
+      protect the information carried in the CER/CEA (Capabilities-
+      Exchange-Request/Capabilities-Exchange-Answer).  This version of
+      Diameter adopts the common approach of defining a well-known
+      secured port that peers should use when communicating via TLS/TCP
+      and DTLS/SCTP.  This new approach augments the existing in-band
+      security negotiation, but it does not completely replace it.  The
+      old method is kept for backward compatibility reasons.
 
    o  Deprecated the exchange of CER/CEA messages in the open state.
-      This feature was implied in the peer state machine table of
-      [RFC3588] but it was not clearly defined anywhere else in that
+      This feature was implied in the peer state machine table of RFC
+      3588, but it was not clearly defined anywhere else in that
       document.  As work on this document progressed, it became clear
-      that the multiplicity of meaning and use of Application Id AVPs in
+      that the multiplicity of meaning and use of Application-Id AVPs in
       the CER/CEA messages (and the messages themselves) is seen as an
+      abuse of the Diameter extensibility rules and thus required
+      simplification.  Capabilities exchange in the open state has been
+      re-introduced in a separate specification [RFC6737], which clearly
+      defines new commands for this feature.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 10]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-      abuse of the Diameter extensibility rules and thus required
-      simplification.  It is assumed that the capabilities exchange in
-      the open state will be re-introduced in a separate specification
-      which clearly defines new commands for this feature.
+Fajardo, et al.              Standards Track                   [Page 11]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
-   o  Simplified Security Requirements.  The use of a secured transport
+   o  Simplified security requirements.  The use of a secured transport
       for exchanging Diameter messages remains mandatory.  However, TLS/
-      TCP and DTLS/SCTP has become the primary method of securing
-      Diameter and IPsec is a secondary alternative.  See Section 13 for
-      details.  The support for the End-to-End security framework
-      (E2ESequence AVP and 'P'-bit in the AVP header) has also been
+      TCP and DTLS/SCTP have become the primary methods of securing
+      Diameter with IPsec as a secondary alternative.  See Section 13
+      for details.  The support for the End-to-End security framework
+      (E2E-Sequence AVP and 'P'-bit in the AVP header) has also been
       deprecated.
 
-   o  Diameter Extensibility Changes.  This includes fixes to the
+   o  Changed Diameter extensibility.  This includes fixes to the
       Diameter extensibility description (Section 1.3 and others) to
       better aid Diameter application designers; in addition, the new
       specification relaxes the policy with respect to the allocation of
-      command codes for vendor-specific uses.
-
-   o  Application Id Usage.  Clarify the proper use of Application Id
-      information which can be found in multiple places within a
-      Diameter message.  This includes correlating Application Ids found
-      in the message headers and AVPs.  These changes also clearly
-      specify the proper Application Id value to use for specific base
-      protocol messages (ASR/ASA, STR/STA) as well as clarifying the
-      content and use of Vendor-Specific-Application-Id.
-
-   o  Routing Fixes.  This document more clearly specifies what
-      information (AVPs and Application Id) can be used for making
+      Command Codes for vendor-specific uses.
+
+   o  Clarified Application Id usage.  Clarify the proper use of
+      Application Id information, which can be found in multiple places
+      within a Diameter message.  This includes correlating Application
+      Ids found in the message headers and AVPs.  These changes also
+      clearly specify the proper Application Id value to use for
+      specific base protocol messages (ASR/ASA, STR/STA) as well as
+      clarify the content and use of Vendor-Specific-Application-Id.
+
+   o  Clarified routing fixes.  This document more clearly specifies
+      what information (AVPs and Application Ids) can be used for making
       general routing decisions.  A rule for the prioritization of
       redirect routing criteria when multiple route entries are found
-      via redirects has also been added (See Section 6.13 for details).
+      via redirects has also been added (see Section 6.13).
 
-   o  Simplification of Diameter Peer Discovery.  The Diameter discovery
+   o  Simplified Diameter peer discovery.  The Diameter discovery
       process now supports only widely used discovery schemes; the rest
       have been deprecated (see Section 5.2 for details).
 
-   There are many other many miscellaneous fixes that have been
-   introduced in this document that may not be considered significant
-   but they are important nonetheless.  Examples are removal of obsolete
-   types, fixes to command ABNFs, fixes to the state machine,
-   clarification of the election process, message validation, fixes to
-   Failed-AVP and Result-Code AVP values, etc.  A comprehensive list of
-   changes is not shown here for practical reasons.
-
-
-
+   There are many other miscellaneous fixes that have been introduced in
+   this document that may not be considered significant, but they have
+   value nonetheless.  Examples are removal of obsolete types, fixes to
+   the state machine, clarification of the election process, message
+   validation, fixes to Failed-AVP and Result-Code AVP values, etc.  All
+   of the errata filed against RFC 3588 prior to the publication of this
+   document have been addressed.  A comprehensive list of changes is not
+   shown here for practical reasons.
 
+1.2.  Terminology
 
+   AAA
 
+      Authentication, Authorization, and Accounting.
 
-Fajardo, et al.           Expires July 24, 2011                [Page 11]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-1.2.  Terminology
 
-   AAA
 
-      Authentication, Authorization and Accounting.
+Fajardo, et al.              Standards Track                   [Page 12]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    ABNF
@@ -631,14 +683,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
       is used to define message exchanges in a bi-directional
       communications protocol.
 
-
    Accounting
 
       The act of collecting information on resource usage for the
-      purpose of capacity planning, auditing, billing or cost
+      purpose of capacity planning, auditing, billing, or cost
       allocation.
 
-
    Accounting Record
 
       An accounting record represents a summary of the resource
@@ -647,114 +697,102 @@ Internet-Draft           Diameter Base Protocol             January 2011
       accounting events or accounting events from several devices
       serving the same user.
 
-
    Authentication
 
       The act of verifying the identity of an entity (subject).
 
-
    Authorization
 
       The act of determining whether a requesting entity (subject) will
       be allowed access to a resource (object).
 
-
-   AVP
+   Attribute-Value Pair (AVP)
 
       The Diameter protocol consists of a header followed by one or more
       Attribute-Value-Pairs (AVPs).  An AVP includes a header and is
       used to encapsulate protocol-specific data (e.g., routing
-      information) as well as authentication, authorization or
+      information) as well as authentication, authorization, or
+      accounting information.
 
+   Command Code Format (CCF)
 
+      A modified form of ABNF used to define Diameter commands (see
+      Section 3.2).
 
-Fajardo, et al.           Expires July 24, 2011                [Page 12]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   Diameter Agent
 
+      A Diameter Agent is a Diameter node that provides relay, proxy,
+      redirect, or translation services.
 
-      accounting information.
 
 
-   Diameter Agent
 
-      A Diameter Agent is a Diameter Node that provides either relay,
-      proxy, redirect or translation services.
+Fajardo, et al.              Standards Track                   [Page 13]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Diameter Client
 
-      A Diameter Client is a Diameter Node that supports Diameter client
-      applications as well as the base protocol.  Diameter Clients are
+      A Diameter client is a Diameter node that supports Diameter client
+      applications as well as the base protocol.  Diameter clients are
       often implemented in devices situated at the edge of a network and
       provide access control services for that network.  Typical
-      examples of Diameter Clients include the Network Access Server
+      examples of Diameter clients include the Network Access Server
       (NAS) and the Mobile IP Foreign Agent (FA).
 
-
    Diameter Node
 
-      A Diameter Node is a host process that implements the Diameter
-      protocol, and acts either as a Client, Agent or Server.
-
+      A Diameter node is a host process that implements the Diameter
+      protocol and acts as either a client, an agent, or a server.
 
    Diameter Peer
 
-      If a Diameter Node shares a direct transport connection with
-      another Diameter Node, it is a Diameter Peer to that Diameter
-      Node.
-
+      Two Diameter nodes sharing a direct TCP or SCTP transport
+      connection are called Diameter peers.
 
    Diameter Server
 
-      A Diameter Server is a Diameter Node that handles authentication,
-      authorization and accounting requests for a particular realm.  By
-      its very nature, a Diameter Server must support Diameter server
+      A Diameter server is a Diameter node that handles authentication,
+      authorization, and accounting requests for a particular realm.  By
+      its very nature, a Diameter server must support Diameter server
       applications in addition to the base protocol.
 
-
    Downstream
 
       Downstream is used to identify the direction of a particular
-      Diameter message from the Home Server towards the Diameter Client.
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 13]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+      Diameter message from the home server towards the Diameter client.
 
    Home Realm
 
       A Home Realm is the administrative domain with which the user
       maintains an account relationship.
 
-
    Home Server
 
-      A Diameter Server which serves the Home Realm.
-
+      A Diameter server that serves the Home Realm.
 
-   Interim accounting
+   Interim Accounting
 
       An interim accounting message provides a snapshot of usage during
-      a user's session.  It is typically implemented in order to provide
-      for partial accounting of a user's session in the case a device
-      reboot or other network problem prevents the delivery of a session
-      summary message or session record.
+      a user's session.  Typically, it is implemented in order to
+      provide for partial accounting of a user's session in case a
+      device reboot or other network problem prevents the delivery of a
+      session summary message or session record.
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 14]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Local Realm
 
       A local realm is the administrative domain providing services to a
       user.  An administrative domain may act as a local realm for
-      certain users, while being a home realm for others.
-
+      certain users while being a home realm for others.
 
    Multi-session
 
@@ -764,60 +802,56 @@ Internet-Draft           Diameter Base Protocol             January 2011
       leg of the bundle would be a session while the entire bundle would
       be a multi-session.
 
-
    Network Access Identifier
 
       The Network Access Identifier, or NAI [RFC4282], is used in the
       Diameter protocol to extract a user's identity and realm.  The
       identity is used to identify the user during authentication and/or
-      authorization, while the realm is used for message routing
+      authorization while the realm is used for message routing
       purposes.
 
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 14]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    Proxy Agent or Proxy
 
       In addition to forwarding requests and responses, proxies make
       policy decisions relating to resource usage and provisioning.
-      This is typically accomplished by tracking the state of NAS
-      devices.  While proxies typically do not respond to client
-      Requests prior to receiving a Response from the server, they may
-      originate Reject messages in cases where policies are violated.
-      As a result, proxies need to understand the semantics of the
-      messages passing through them, and may not support all Diameter
+      Typically, this is accomplished by tracking the state of NAS
+      devices.  While proxies usually do not respond to client requests
+      prior to receiving a response from the server, they may originate
+      Reject messages in cases where policies are violated.  As a
+      result, proxies need to understand the semantics of the messages
+      passing through them, and they may not support all Diameter
       applications.
 
-
    Realm
 
       The string in the NAI that immediately follows the '@' character.
-      NAI realm names are required to be unique, and are piggybacked on
+      NAI realm names are required to be unique and are piggybacked on
       the administration of the DNS namespace.  Diameter makes use of
       the realm, also loosely referred to as domain, to determine
-      whether messages can be satisfied locally, or whether they must be
+      whether messages can be satisfied locally or whether they must be
       routed or redirected.  In RADIUS, realm names are not necessarily
       piggybacked on the DNS namespace but may be independent of it.
 
 
-   Real-time Accounting
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 15]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   Real-Time Accounting
 
       Real-time accounting involves the processing of information on
-      resource usage within a defined time window.  Time constraints are
-      typically imposed in order to limit financial risk.  The Diameter
-      Credit Control Application [RFC4006] is an example of an
+      resource usage within a defined time window.  Typically, time
+      constraints are imposed in order to limit financial risk.  The
+      Diameter Credit-Control Application [RFC4006] is an example of an
       application that defines real-time accounting functionality.
 
-
    Relay Agent or Relay
 
       Relays forward requests and responses based on routing-related
@@ -827,20 +861,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
       the semantics of messages or non-routing AVPs, and are capable of
       handling any Diameter application or message type.  Since relays
       make decisions based on information in routing AVPs and realm
-      forwarding tables they do not keep state on NAS resource usage or
+      forwarding tables, they do not keep state on NAS resource usage or
       sessions in progress.
 
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 15]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    Redirect Agent
 
       Rather than forwarding requests and responses between clients and
@@ -850,11 +873,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
       client and server.  Redirect agents do not originate messages and
       are capable of handling any message type, although they may be
       configured only to redirect messages of certain types, while
-      acting as relay or proxy agents for other types.  As with proxy
+      acting as relay or proxy agents for other types.  As with relay
       agents, redirect agents do not keep state with respect to sessions
       or NAS resources.
 
-
    Session
 
       A session is a related progression of events devoted to a
@@ -863,14 +885,19 @@ Internet-Draft           Diameter Base Protocol             January 2011
       packets with the same Session-Id are considered to be part of the
       same session.
 
-
    Stateful Agent
 
       A stateful agent is one that maintains session state information,
       by keeping track of all authorized active sessions.  Each
       authorized session is bound to a particular service, and its state
-      is considered active either until it is notified otherwise, or by
-      expiration.
+      is considered active either until it is notified otherwise or
+      until expiration.
+
+
+
+Fajardo, et al.              Standards Track                   [Page 16]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Sub-session
@@ -881,53 +908,33 @@ Internet-Draft           Diameter Base Protocol             January 2011
       during the same session) or serially.  These changes in sessions
       are tracked with the Accounting-Sub-Session-Id.
 
-
-   Transaction state
+   Transaction State
 
       The Diameter protocol requires that agents maintain transaction
       state, which is used for failover purposes.  Transaction state
-      implies that upon forwarding a request, the Hop-by-Hop identifier
+      implies that upon forwarding a request, the Hop-by-Hop Identifier
       is saved; the field is replaced with a locally unique identifier,
       which is restored to its original value when the corresponding
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 16]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       answer is received.  The request's state is released upon receipt
       of the answer.  A stateless agent is one that only maintains
       transaction state.
 
-
    Translation Agent
 
-      A translation agent is a stateful Diameter node that performs
-      protocol translation between Diameter and another AAA protocol,
-      such as RADIUS.
-
-
-   Transport Connection
-
-      A transport connection is a TCP or SCTP connection existing
-      directly between two Diameter peers, otherwise known as a Peer-to-
-      Peer Connection.
-
+      A translation agent (TLA in Figure 4) is a stateful Diameter node
+      that performs protocol translation between Diameter and another
+      AAA protocol, such as RADIUS.
 
    Upstream
 
       Upstream is used to identify the direction of a particular
-      Diameter message from the Diameter Client towards the Home Server.
-
+      Diameter message from the Diameter client towards the home server.
 
    User
 
       The entity or device requesting or using some resource, in support
       of which a Diameter client has generated a request.
 
-
 1.3.  Approach to Extensibility
 
    The Diameter protocol is designed to be extensible, using several
@@ -941,107 +948,108 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    o  Creating new applications
 
-   From the point of view of extensibility Diameter authentication,
-   authorization and accounting applications are treated in the same
-   way.
-
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 17]
+Fajardo, et al.              Standards Track                   [Page 17]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   Note: Protocol designers should try to re-use existing functionality,
+   From the point of view of extensibility, Diameter authentication,
+   authorization, and accounting applications are treated in the same
+   way.
+
+   Note: Protocol designers should try to reuse existing functionality,
    namely AVP values, AVPs, commands, and Diameter applications.  Reuse
    simplifies standardization and implementation.  To avoid potential
-   interoperability issues it is important to ensure that the semantics
-   of the re-used features are well understood.  Given that Diameter can
-   also carry RADIUS attributes as Diameter AVPs, such re-use
-   considerations apply also to existing RADIUS attributes that may be
+   interoperability issues, it is important to ensure that the semantics
+   of the reused features are well understood.  Given that Diameter can
+   also carry RADIUS attributes as Diameter AVPs, such reuse
+   considerations also apply to existing RADIUS attributes that may be
    useful in a Diameter application.
 
-1.3.1.   Defining New AVP Values
+1.3.1.  Defining New AVP Values
 
    In order to allocate a new AVP value for AVPs defined in the Diameter
-   Base protocol, the IETF needs to approve a new RFC that describes the
+   base protocol, the IETF needs to approve a new RFC that describes the
    AVP value.  IANA considerations for these AVP values are discussed in
-   Section 11.4.
+   Section 11.3.
 
    The allocation of AVP values for other AVPs is guided by the IANA
    considerations of the document that defines those AVPs.  Typically,
-   allocation of new values for an AVP defined in an IETF RFC should
-   require IETF Review [RFC5226], whereas values for vendor-specific
-   AVPs can be allocated by the vendor.
+   allocation of new values for an AVP defined in an RFC would require
+   IETF Review [RFC5226], whereas values for vendor-specific AVPs can be
+   allocated by the vendor.
 
-1.3.2.   Creating New AVPs
+1.3.2.  Creating New AVPs
 
    A new AVP being defined MUST use one of the data types listed in
-   Section 4.2 or Section 4.3.  If an appropriate derived data type is
-   already defined, it SHOULD be used instead of a base data type to
-   encourage reusability and good design practice.
+   Sections 4.2 or 4.3.  If an appropriate derived data type is already
+   defined, it SHOULD be used instead of a base data type to encourage
+   reusability and good design practice.
 
    In the event that a logical grouping of AVPs is necessary, and
    multiple "groups" are possible in a given command, it is recommended
    that a Grouped AVP be used (see Section 4.4).
 
    The creation of new AVPs can happen in various ways.  The recommended
-   approach is to define a new general-purpose AVP in a standards track
-   RFC approved by the IETF.  However, as described in Section 11.1.1
-   there are also other mechanisms.
+   approach is to define a new general-purpose AVP in a Standards Track
+   RFC approved by the IETF.  However, as described in Section 11.1.1,
+   there are other mechanisms.
 
-1.3.3.   Creating New Commands
+1.3.3.  Creating New Commands
 
    A new Command Code MUST be allocated when required AVPs (those
-   indicated as {AVP} in the ABNF definition) are added to, deleted from
+   indicated as {AVP} in the CCF definition) are added to, deleted from,
    or redefined in (for example, by changing a required AVP into an
    optional one) an existing command.
 
-   Furthermore, if the transport characteristics of a command are
-   changed (for example, with respect to the number of round trips
-   required) a new Command Code MUST be registered.
 
 
-
-Fajardo, et al.           Expires July 24, 2011                [Page 18]
+Fajardo, et al.              Standards Track                   [Page 18]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   Furthermore, if the transport characteristics of a command are
+   changed (for example, with respect to the number of round trips
+   required), a new Command Code MUST be registered.
 
-   A change to the ABNF of a command, such as described above, MUST
+   A change to the CCF of a command, such as described above, MUST
    result in the definition of a new Command Code.  This subsequently
-   leads to the need to define a new Diameter Application for any
-   application that will use that new Command.
-
-   The IANA considerations for commands are discussed in Section 11.2.1.
-
-1.3.4.   Creating New Diameter Applications
-
-   Every Diameter application specification MUST have an IANA assigned
-   Application Id (see Section 2.4 and Section 11.3).  The managed
-   Application Id space is flat and there is no relationship between
-   different Diameter applications with respect to their Application
-   Ids. As such, there is no versioning support provided by these
-   application Ids itself; every Diameter application is a standalone
-   application.  If the application has a relationship with other
-   Diameter applications, such a relationship is not known to Diameter.
-
-   Before describing the rules for creating new Diameter applications it
-   is important to discuss the semantics of the AVPs occurrences as
-   stated in the ABNF and the M-bit flag (Section 4.1) for an AVP.
-   There is no relationship imposed between the two; they are set
+   leads to the need to define a new Diameter application for any
+   application that will use that new command.
+
+   The IANA considerations for Command Codes are discussed in
+   Section 3.1.
+
+1.3.4.  Creating New Diameter Applications
+
+   Every Diameter application specification MUST have an IANA-assigned
+   Application Id (see Section 2.4).  The managed Application ID space
+   is flat, and there is no relationship between different Diameter
+   applications with respect to their Application Ids.  As such, there
+   is no versioning support provided by these Application Ids
+   themselves; every Diameter application is a standalone application.
+   If the application has a relationship with other Diameter
+   applications, such a relationship is not known to Diameter.
+
+   Before describing the rules for creating new Diameter applications,
+   it is important to discuss the semantics of the AVP occurrences as
+   stated in the CCF and the M-bit flag (Section 4.1) for an AVP.  There
+   is no relationship imposed between the two; they are set
    independently.
 
-   o  The ABNF indicates what AVPs are placed into a Diameter Command by
-      the sender of that Command.  Often, since there are multiple modes
-      of protocol interactions many of the AVPs are indicated as
+   o  The CCF indicates what AVPs are placed into a Diameter command by
+      the sender of that command.  Often, since there are multiple modes
+      of protocol interactions, many of the AVPs are indicated as
       optional.
 
    o  The M-bit allows the sender to indicate to the receiver whether or
       not understanding the semantics of an AVP and its content is
       mandatory.  If the M-bit is set by the sender and the receiver
-      does not understand the AVP or the values carried within that AVP
+      does not understand the AVP or the values carried within that AVP,
       then a failure is generated (see Section 7).
 
    It is the decision of the protocol designer when to develop a new
@@ -1050,77 +1058,48 @@ Internet-Draft           Diameter Base Protocol             January 2011
    of the following criteria are met:
 
 
-   M-bit Setting
 
-      An AVP with the M-bit in the MUST column of the AVP flag table is
-      added to an existing Command/Application.
 
-      An AVP with the M-bit in the MAY column of the AVP flag table is
-      added to an existing Command/Application.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 19]
+Fajardo, et al.              Standards Track                   [Page 19]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   M-bit Setting
+
+      An AVP with the M-bit in the MUST column of the AVP flag table is
+      added to an existing Command/Application.  An AVP with the M-bit
+      in the MAY column of the AVP flag table is added to an existing
+      Command/Application.
 
       Note: The M-bit setting for a given AVP is relevant to an
-      Application and each command within that application which
-      includes the AVP.  That is, if an AVP appears in two commands for
+      Application and each command within that application that includes
+      the AVP.  That is, if an AVP appears in two commands for
       application Foo and the M-bit settings are different in each
       command, then there should be two AVP flag tables describing when
       to set the M-bit.
 
    Commands
 
-      A new command is used within the existing application either
-      because an additional command is added, an existing command has
+      A new command is used within the existing application because
+      either an additional command is added, an existing command has
       been modified so that a new Command Code had to be registered, or
       a command has been deleted.
 
-   If the ABNF definition of a command allows it, an implementation may
+   AVP Flag bits
+
+      If an existing application changes the meaning/semantics of its
+      AVP Flags or adds new flag bits, then a new Diameter application
+      MUST be created.
+
+   If the CCF definition of a command allows it, an implementation may
    add arbitrary optional AVPs with the M-bit cleared (including vendor-
    specific AVPs) to that command without needing to define a new
    application.  Please refer to Section 11.1.1 for details.
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 20]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 2.  Protocol Overview
 
    The base Diameter protocol concerns itself with establishing
@@ -1137,9 +1116,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
    The initial request for authentication and/or authorization of a user
    would include the Session-Id AVP.  The Session-Id is then used in all
    subsequent messages to identify the user's session (see Section 8 for
-   more information).  The communicating party may accept the request,
-   or reject it by returning an answer message with the Result-Code AVP
-   set to indicate an error occurred.  The specific behavior of the
+
+
+
+Fajardo, et al.              Standards Track                   [Page 20]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   more information).  The communicating party may accept the request or
+   reject it by returning an answer message with the Result-Code AVP set
+   to indicate that an error occurred.  The specific behavior of the
    Diameter server or client receiving a request depends on the Diameter
    application employed.
 
@@ -1153,30 +1140,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
    applications.  For authentication and authorization, it is always
    extended for a particular application.
 
-   Diameter Clients MUST support the base protocol, which includes
+   Diameter clients MUST support the base protocol, which includes
    accounting.  In addition, they MUST fully support each Diameter
    application that is needed to implement the client's service, e.g.,
-   NASREQ and/or Mobile IPv4.  A Diameter Client MUST be referred to as
-   "Diameter X Client" where X is the application which it supports, and
-   not a "Diameter Client".
+   Network Access Server Requirements (NASREQ) [RFC2881] and/or Mobile
+   IPv4.  A Diameter client MUST be referred to as "Diameter X Client"
+   where X is the application that it supports and not a "Diameter
+   Client".
 
-   Diameter Servers MUST support the base protocol, which includes
+   Diameter servers MUST support the base protocol, which includes
    accounting.  In addition, they MUST fully support each Diameter
    application that is needed to implement the intended service, e.g.,
-   NASREQ and/or Mobile IPv4.  A Diameter Server MUST be referred to as
-   "Diameter X Server" where X is the application which it supports, and
+   NASREQ and/or Mobile IPv4.  A Diameter server MUST be referred to as
+   "Diameter X Server" where X is the application that it supports, and
    not a "Diameter Server".
 
-   Diameter Relays and redirect agents are transparent to the Diameter
-   applications but they MUST support the Diameter base protocol, which
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 21]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
+   Diameter relays and redirect agents are transparent to the Diameter
+   applications, but they MUST support the Diameter base protocol, which
    includes accounting, and all Diameter applications.
 
    Diameter proxies MUST support the base protocol, which includes
@@ -1186,55 +1166,75 @@ Internet-Draft           Diameter Base Protocol             January 2011
    "Diameter X Proxy" where X is the application which it supports, and
    not a "Diameter Proxy".
 
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 21]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 2.1.  Transport
 
    The Diameter Transport profile is defined in [RFC3539].
 
-   The base Diameter protocol is run on port 3868 for both TCP [RFC793]
-   and SCTP [RFC4960].  For TLS [RFC5246] and DTLS [RFC4347], a Diameter
-   node that initiate a connection prior to any message exchanges MUST
-   run on port [TBD].  It is assumed that TLS is run on top of TCP when
-   it is used and DTLS is run on top of SCTP when it is used.
+   The base Diameter protocol is run on port 3868 for both TCP [RFC0793]
+   and SCTP [RFC4960].  For TLS [RFC5246] and Datagram Transport Layer
+   Security (DTLS) [RFC6347], a Diameter node that initiates a
+   connection prior to any message exchanges MUST run on port 5658.  It
+   is assumed that TLS is run on top of TCP when it is used, and DTLS is
+   run on top of SCTP when it is used.
 
    If the Diameter peer does not support receiving TLS/TCP and DTLS/SCTP
-   connections on port [TBD], i.e. the peer complies only with
-   [RFC3588], then the initiator MAY revert to using TCP or SCTP and on
-   port 3868.  Note that this scheme is kept for the purpose of
-   backwards compatibility only and that there are inherent security
-   vulnerabilities when the initial CER/CEA messages are sent un-
-   protected (see Section 5.6).
+   connections on port 5658 (i.e., the peer complies only with RFC
+   3588), then the initiator MAY revert to using TCP or SCTP on port
+   3868.  Note that this scheme is kept only for the purpose of backward
+   compatibility and that there are inherent security vulnerabilities
+   when the initial CER/CEA messages are sent unprotected (see
+   Section 5.6).
 
-   Diameter clients MUST support either TCP or SCTP, while agents and
-   servers SHOULD support both.
+   Diameter clients MUST support either TCP or SCTP; agents and servers
+   SHOULD support both.
 
    A Diameter node MAY initiate connections from a source port other
    than the one that it declares it accepts incoming connections on, and
-   MUST be prepared to receive connections on port 3868 for TCP or SCTP
-   and port [TBD] for TLS/TCP and DTLS/SCTP connections.  A given
-   Diameter instance of the peer state machine MUST NOT use more than
-   one transport connection to communicate with a given peer, unless
-   multiple instances exist on the peer in which case a separate
-   connection per process is allowed.
+   it MUST always be prepared to receive connections on port 3868 for
+   TCP or SCTP and port 5658 for TLS/TCP and DTLS/SCTP connections.
+   When DNS-based peer discovery (Section 5.2) is used, the port numbers
+   received from SRV records take precedence over the default ports
+   (3868 and 5658).
+
+   A given Diameter instance of the peer state machine MUST NOT use more
+   than one transport connection to communicate with a given peer,
+   unless multiple instances exist on the peer, in which, case a
+   separate connection per process is allowed.
 
    When no transport connection exists with a peer, an attempt to
-   connect SHOULD be periodically made.  This behavior is handled via
+   connect SHOULD be made periodically.  This behavior is handled via
    the Tc timer (see Section 12 for details), whose recommended value is
    30 seconds.  There are certain exceptions to this rule, such as when
    a peer has terminated the transport connection stating that it does
    not wish to communicate.
 
    When connecting to a peer and either zero or more transports are
-   specified, TLS SHOULD be tried first, followed by DTLS, then by TCP
+   specified, TLS SHOULD be tried first, followed by DTLS, then by TCP,
+   and finally by SCTP.  See Section 5.2 for more information on peer
+   discovery.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 22]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-   and finally by SCTP.  See Section 5.2 for more information on peer
-   discovery.
+Fajardo, et al.              Standards Track                   [Page 22]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    Diameter implementations SHOULD be able to interpret ICMP protocol
    port unreachable messages as explicit indications that the server is
@@ -1253,18 +1253,18 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Diameter messages SHOULD be mapped into SCTP streams in a way that
    avoids head-of-the-line (HOL) blocking.  Among different ways of
    performing the mapping that fulfill this requirement it is
-   RECOMMENDED that a Diameter node sends every Diameter message
-   (request or response) over the stream zero with the unordered flag
-   set.  However, Diameter nodes MAY select and implement other design
-   alternatives for avoiding HOL blocking such as using multiple streams
-   with the unordered flag cleared (as originally instructed in
-   RFC3588).  On the receiving side, a Diameter entity MUST be ready to
-   receive Diameter messages over any stream and it is free to return
-   responses over a different stream.  This way, both sides manage the
-   available streams in the sending direction, independently of the
-   streams chosen by the other side to send a particular Diameter
-   message.  These messages can be out-of-order and belong to different
-   Diameter sessions.
+   RECOMMENDED that a Diameter node send every Diameter message (request
+   or response) over stream zero with the unordered flag set.  However,
+   Diameter nodes MAY select and implement other design alternatives for
+   avoiding HOL blocking such as using multiple streams with the
+   unordered flag cleared (as originally instructed in RFC 3588).  On
+   the receiving side, a Diameter entity MUST be ready to receive
+   Diameter messages over any stream, and it is free to return responses
+   over a different stream.  This way, both sides manage the available
+   streams in the sending direction, independently of the streams chosen
+   by the other side to send a particular Diameter message.  These
+   messages can be out-of-order and belong to different Diameter
+   sessions.
 
    Out-of-order delivery has special concerns during a connection
    establishment and termination.  When a connection is established, the
@@ -1275,30 +1275,37 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the connection.  In order to avoid this race condition, the receiver
    side SHOULD NOT use out-of-order delivery methods until the first
    message has been received from the initiator, proving that it has
-   moved to I-Open state.  To trigger such message, the receiver side
-   could send a DWR immediatly after sending CEA.  Upon reception of the
-   corresponding DWA, the receiver side should start using out-of-order
-   delivery methods to counter the HOL blocking.
+   moved to I-Open state.  To trigger such a message, the receiver side
+   could send a DWR immediately after sending a CEA.  Upon reception of
+   the corresponding DWA, the receiver side should start using out-of-
+   order delivery methods to counter the HOL blocking.
 
    Another race condition may occur when DPR and DPA messages are used.
+   Both DPR and DPA are small in size; thus, they may be delivered to
+   the peer faster than application messages when an out-of-order
+   delivery mechanism is used.  Therefore, it is possible that a DPR/DPA
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 23]
+Fajardo, et al.              Standards Track                   [Page 23]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   exchange completes while application messages are still in transit,
+   resulting in a loss of these messages.  An implementation could
+   mitigate this race condition, for example, using timers, and wait for
+   a short period of time for pending application level messages to
+   arrive before proceeding to disconnect the transport connection.
+   Eventually, lost messages are handled by the retransmission mechanism
+   described in Section 5.5.4.
 
-   Both DPR and DPA are small in size, thus they may be delivered faster
-   to the peer than application messages when out-of-order delivery
-   mechanism is used.  Therefore, it is possible that a DPR/DPA exchange
-   completes while application messages are still in transit, resulting
-   to a loss of these messages.  An implementation could mitigate this
-   race condition, for example, using timers and wait for a short period
-   of time for pending application level messages to arrive before
-   proceeding to disconnect the transport connection.  Eventually, lost
-   messages are handled by the retransmission mechanism described in
-   Section 5.5.4.
+   A Diameter agent SHOULD use dedicated payload protocol identifiers
+   (PPIDs) for clear text and encrypted SCTP DATA chunks instead of only
+   using the unspecified payload protocol identifier (value 0).  For
+   this purpose, two PPID values are allocated: the PPID value 46 is for
+   Diameter messages in clear text SCTP DATA chunks, and the PPID value
+   47 is for Diameter messages in protected DTLS/SCTP DATA chunks.
 
 2.2.  Securing Diameter Messages
 
@@ -1307,7 +1314,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the use of TLS/TCP and DTLS/SCTP.  If desired, alternative security
    mechanisms that are independent of Diameter, such as IPsec [RFC4301],
    can be deployed to secure connections between peers.  The Diameter
-   protocol MUST NOT be used without any security mechanism.
+   protocol MUST NOT be used without one of TLS, DTLS, or IPsec.
 
 2.3.  Diameter Application Compliance
 
@@ -1318,37 +1325,40 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    Implementations MAY add arbitrary optional AVPs with the M-bit
    cleared (including vendor-specific AVPs) to a command defined in an
-   application, but only if the command's ABNF syntax specification
+   application, but only if the command's CCF syntax specification
    allows for it.  Please refer to Section 11.1.1 for details.
 
 2.4.  Application Identifiers
 
-   Each Diameter application MUST have an IANA assigned Application Id
-   (see Section 11.3).  The base protocol does not require an
-   Application Id since its support is mandatory.  During the
-   capabilities exchange, Diameter nodes inform their peers of locally
-   supported applications.  Furthermore, all Diameter messages contain
-   an Application Id, which is used in the message forwarding process.
+   Each Diameter application MUST have an IANA-assigned Application ID.
+   The base protocol does not require an Application Id since its
+   support is mandatory.  During the capabilities exchange, Diameter
+   nodes inform their peers of locally supported applications.
+   Furthermore, all Diameter messages contain an Application Id, which
+   is used in the message forwarding process.
 
-   The following Application Id values are defined:
 
-         Diameter Common Messages      0
-         Diameter Base Accounting      3
-         Relay                         0xffffffff
 
-   Relay and redirect agents MUST advertise the Relay Application
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 24]
+
+Fajardo, et al.              Standards Track                   [Page 24]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   The following Application Id values are defined:
+
+         Diameter common message       0
+         Diameter base accounting      3
+         Relay                         0xffffffff
 
-   Identifier, while all other Diameter nodes MUST advertise locally
-   supported applications.  The receiver of a Capabilities Exchange
-   message advertising Relay service MUST assume that the sender
-   supports all current and future applications.
+   Relay and redirect agents MUST advertise the Relay Application ID,
+   while all other Diameter nodes MUST advertise locally supported
+   applications.  The receiver of a Capabilities Exchange message
+   advertising relay service MUST assume that the sender supports all
+   current and future applications.
 
    Diameter relay and proxy agents are responsible for finding an
    upstream server that supports the application of a particular
@@ -1358,16 +1368,15 @@ Internet-Draft           Diameter Base Protocol             January 2011
 2.5.  Connections vs. Sessions
 
    This section attempts to provide the reader with an understanding of
-   the difference between connection and session, which are terms used
-   extensively throughout this document.
+   the difference between "connection" and "session", which are terms
+   used extensively throughout this document.
 
-   A connection refers to a transport level connection between two peers
+   A connection refers to a transport-level connection between two peers
    that is used to send and receive Diameter messages.  A session is a
-   logical concept at the application layer existing between the
+   logical concept at the application layer that exists between the
    Diameter client and the Diameter server; it is identified via the
    Session-Id AVP.
 
-
              +--------+          +-------+          +--------+
              | Client |          | Relay |          | Server |
              +--------+          +-------+          +--------+
@@ -1377,100 +1386,93 @@ Internet-Draft           Diameter Base Protocol             January 2011
                       <----------------------------->
                               User session x
 
-                Figure 1: Diameter connections and sessions
+                Figure 1: Diameter Connections and Sessions
 
    In the example provided in Figure 1, peer connection A is established
-   between the Client and the Relay.  Peer connection B is established
-   between the Relay and the Server.  User session X spans from the
-   Client via the Relay to the Server.  Each "user" of a service causes
+   between the client and the relay.  Peer connection B is established
+   between the relay and the server.  User session X spans from the
+   client via the relay to the server.  Each "user" of a service causes
    an auth request to be sent, with a unique session identifier.  Once
    accepted by the server, both the client and the server are aware of
    the session.
 
-   It is important to note that there is no relationship between a
-   connection and a session, and that Diameter messages for multiple
-   sessions are all multiplexed through a single connection.  Also note
-   that Diameter messages pertaining to the session, both application
-   specific and those that are defined in this document such as ASR/ASA,
-   RAR/RAA and STR/STA MUST carry the Application Id of the application.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 25]
+Fajardo, et al.              Standards Track                   [Page 25]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   Diameter messages pertaining to peer connection establishment and
-   maintenance such as CER/CEA, DWR/DWA and DPR/DPA MUST carry an
-   Application Id of zero (0).
+   It is important to note that there is no relationship between a
+   connection and a session, and that Diameter messages for multiple
+   sessions are all multiplexed through a single connection.  Also, note
+   that Diameter messages pertaining to the session, both application-
+   specific and those that are defined in this document such as ASR/ASA,
+   RAR/RAA, and STR/STA, MUST carry the Application Id of the
+   application.  Diameter messages pertaining to peer connection
+   establishment and maintenance such as CER/CEA, DWR/DWA, and DPR/DPA
+   MUST carry an Application Id of zero (0).
 
 2.6.  Peer Table
 
-   The Diameter Peer Table is used in message forwarding, and referenced
-   by the Routing Table.  A Peer Table entry contains the following
-   fields:
+   The Diameter peer table is used in message forwarding and is
+   referenced by the routing table.  A peer table entry contains the
+   following fields:
 
-   Host identity
+   Host Identity
 
-      Following the conventions described for the DiameterIdentity
-      derived AVP data format in Section 4.3.  This field contains the
+      Following the conventions described for the DiameterIdentity-
+      derived AVP data format in Section 4.3.1, this field contains the
       contents of the Origin-Host (Section 6.3) AVP found in the CER or
       CEA message.
 
-
    StatusT
 
-      This is the state of the peer entry, and MUST match one of the
+      This is the state of the peer entry, and it MUST match one of the
       values listed in Section 5.6.
 
-
    Static or Dynamic
 
       Specifies whether a peer entry was statically configured or
       dynamically discovered.
 
-
-   Expiration time
+   Expiration Time
 
       Specifies the time at which dynamically discovered peer table
-      entries are to be either refreshed, or expired.
-
+      entries are to be either refreshed or expired.  If public key
+      certificates are used for Diameter security (e.g., with TLS), this
+      value MUST NOT be greater than the expiry times in the relevant
+      certificates.
 
    TLS/TCP and DTLS/SCTP Enabled
 
       Specifies whether TLS/TCP and DTLS/SCTP is to be used when
       communicating with the peer.
 
-
    Additional security information, when needed (e.g., keys,
-   certificates)
-
-
+   certificates).
 
 
 
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 26]
+Fajardo, et al.              Standards Track                   [Page 26]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 2.7.  Routing Table
 
    All Realm-Based routing lookups are performed against what is
-   commonly known as the Routing Table (see Section 12).  A Routing
-   Table Entry contains the following fields:
+   commonly known as the routing table (see Section 12).  Each routing
+   table entry contains the following fields:
 
    Realm Name
 
-      This is the field that is MUST be used as a primary key in the
+      This is the field that MUST be used as a primary key in the
       routing table lookups.  Note that some implementations perform
       their lookups based on longest-match-from-the-right on the realm
       rather than requiring an exact match.
 
-
    Application Identifier
 
       An application is identified by an Application Id.  A route entry
@@ -1478,21 +1480,19 @@ Internet-Draft           Diameter Base Protocol             January 2011
       the message header.  This field MUST be used as a secondary key
       field in routing table lookups.
 
-
    Local Action
 
       The Local Action field is used to identify how a message should be
       treated.  The following actions are supported:
 
-
-      1.  LOCAL - Diameter messages that can be satisfied locally, and
-          do not need to be routed to another Diameter entity.
+      1.  LOCAL - Diameter messages that can be satisfied locally and do
+          not need to be routed to another Diameter entity.
 
       2.  RELAY - All Diameter messages that fall within this category
-          MUST be routed to a next hop Diameter entity that is indicated
+          MUST be routed to a next-hop Diameter entity that is indicated
           by the identifier described below.  Routing is done without
           modifying any non-routing AVPs.  See Section 6.1.9 for
-          relaying guidelines
+          relaying guidelines.
 
       3.  PROXY - All Diameter messages that fall within this category
           MUST be routed to a next Diameter entity that is indicated by
@@ -1504,47 +1504,53 @@ Internet-Draft           Diameter Base Protocol             January 2011
       4.  REDIRECT - Diameter messages that fall within this category
           MUST have the identity of the home Diameter server(s)
           appended, and returned to the sender of the message.  See
-          Section 6.1.8 for redirect guidelines.
+          Section 6.1.8 for redirection guidelines.
+
+
+
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 27]
+Fajardo, et al.              Standards Track                   [Page 27]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Server Identifier
 
-      One or more servers to which the message is to be routed.  These
-      servers MUST also be present in the Peer table.  When the Local
-      Action is set to RELAY or PROXY, this field contains the identity
-      of the server(s) the message MUST be routed to.  When the Local
+      The identity of one or more servers to which the message is to be
+      routed.  This identity MUST also be present in the Host Identity
+      field of the peer table (Section 2.6).  When the Local Action is
+      set to RELAY or PROXY, this field contains the identity of the
+      server(s) to which the message MUST be routed.  When the Local
       Action field is set to REDIRECT, this field contains the identity
-      of one or more servers the message MUST be redirected to.
+      of one or more servers to which the message MUST be redirected.
 
    Static or Dynamic
 
       Specifies whether a route entry was statically configured or
       dynamically discovered.
 
-   Expiration time
+   Expiration Time
 
       Specifies the time at which a dynamically discovered route table
-      entry expires.
+      entry expires.  If public key certificates are used for Diameter
+      security (e.g., with TLS), this value MUST NOT be greater than the
+      expiry time in the relevant certificates.
 
    It is important to note that Diameter agents MUST support at least
-   one of the LOCAL, RELAY, PROXY or REDIRECT modes of operation.
+   one of the LOCAL, RELAY, PROXY, or REDIRECT modes of operation.
    Agents do not need to support all modes of operation in order to
-   conform with the protocol specification, but MUST follow the protocol
-   compliance guidelines in Section 2.  Relay agents and proxies MUST
-   NOT reorder AVPs.
+   conform with the protocol specification, but they MUST follow the
+   protocol compliance guidelines in Section 2.  Relay agents and
+   proxies MUST NOT reorder AVPs.
 
    The routing table MAY include a default entry that MUST be used for
    any requests not matching any of the other entries.  The routing
    table MAY consist of only such an entry.
 
    When a request is routed, the target server MUST have advertised the
-   Application Id (see Section 2.4) for the given message, or have
+   Application Id (see Section 2.4) for the given message or have
    advertised itself as a relay or proxy agent.  Otherwise, an error is
    returned with the Result-Code AVP set to DIAMETER_UNABLE_TO_DELIVER.
 
@@ -1552,23 +1558,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    In addition to clients and servers, the Diameter protocol introduces
    relay, proxy, redirect, and translation agents, each of which is
-   defined in Section 1.3.  These Diameter agents are useful for several
+   defined in Section 1.2.  Diameter agents are useful for several
    reasons:
 
    o  They can distribute administration of systems to a configurable
       grouping, including the maintenance of security associations.
 
-   o  They can be used for concentration of requests from an number of
-      co-located or distributed NAS equipment sets to a set of like user
-      groups.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 28]
+Fajardo, et al.              Standards Track                   [Page 28]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+   o  They can be used for concentration of requests from a number of
+      co-located or distributed NAS equipment sets to a set of like user
+      groups.
+
    o  They can do value-added processing to the requests or responses.
 
    o  They can be used for load balancing.
@@ -1578,7 +1585,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    The Diameter protocol requires that agents maintain transaction
    state, which is used for failover purposes.  Transaction state
-   implies that upon forwarding a request, its Hop-by-Hop identifier is
+   implies that upon forwarding a request, its Hop-by-Hop Identifier is
    saved; the field is replaced with a locally unique identifier, which
    is restored to its original value when the corresponding answer is
    received.  The request's state is released upon receipt of the
@@ -1593,7 +1600,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    A stateful agent is one that maintains session state information by
    keeping track of all authorized active sessions.  Each authorized
    session is bound to a particular service, and its state is considered
-   active either until the agent is notified otherwise, or the session
+   active until either the agent is notified otherwise or the session
    expires.  Each authorized session has an expiration, which is
    communicated by Diameter servers via the Session-Timeout AVP.
 
@@ -1604,40 +1611,43 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    o  Limiting resources authorized to a particular user
 
-   o  Per user or transaction auditing
+   o  Per-user or per-transaction auditing
 
    A Diameter agent MAY act in a stateful manner for some requests and
    be stateless for others.  A Diameter implementation MAY act as one
-   type of agent for some requests, and as another type of agent for
+   type of agent for some requests and as another type of agent for
    others.
 
-2.8.1.  Relay Agents
 
-   Relay Agents are Diameter agents that accept requests and route
-   messages to other Diameter nodes based on information found in the
-   messages (e.g., Destination-Realm).  This routing decision is
-   performed using a list of supported realms, and known peers.  This is
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 29]
+
+Fajardo, et al.              Standards Track                   [Page 29]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+2.8.1.  Relay Agents
 
-   known as the Routing Table, as is defined further in Section 2.7.
+   Relay agents are Diameter agents that accept requests and route
+   messages to other Diameter nodes based on information found in the
+   messages (e.g., the value of the Destination-Realm AVP Section 6.6).
+   This routing decision is performed using a list of supported realms
+   and known peers.  This is known as the routing table, as is defined
+   further in Section 2.7.
 
    Relays may, for example, be used to aggregate requests from multiple
    Network Access Servers (NASes) within a common geographical area
-   (POP).  The use of Relays is advantageous since it eliminates the
-   need for NASes to be configured with the necessary security
-   information they would otherwise require to communicate with Diameter
-   servers in other realms.  Likewise, this reduces the configuration
-   load on Diameter servers that would otherwise be necessary when NASes
-   are added, changed or deleted.
+   (Point of Presence, POP).  The use of relays is advantageous since it
+   eliminates the need for NASes to be configured with the necessary
+   security information they would otherwise require to communicate with
+   Diameter servers in other realms.  Likewise, this reduces the
+   configuration load on Diameter servers that would otherwise be
+   necessary when NASes are added, changed, or deleted.
 
    Relays modify Diameter messages by inserting and removing routing
-   information, but do not modify any other portion of a message.
+   information, but they do not modify any other portion of a message.
    Relays SHOULD NOT maintain session state but MUST maintain
    transaction state.
 
@@ -1650,44 +1660,46 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
                   Figure 2: Relaying of Diameter messages
 
-   The example provided in Figure 2 depicts a request issued from NAS,
+   The example provided in Figure 2 depicts a request issued from a NAS,
    which is an access device, for the user [email protected].  Prior to
-   issuing the request, NAS performs a Diameter route lookup, using
+   issuing the request, the NAS performs a Diameter route lookup, using
    "example.com" as the key, and determines that the message is to be
-   relayed to DRL, which is a Diameter Relay.  DRL performs the same
-   route lookup as NAS, and relays the message to HMS, which is
-   example.com's Home Diameter Server.  HMS identifies that the request
-   can be locally supported (via the realm), processes the
+   relayed to a DRL, which is a Diameter relay.  The DRL performs the
+   same route lookup as the NAS, and relays the message to the HMS,
+   which is example.com's home server.  The HMS identifies that the
+   request can be locally supported (via the realm), processes the
    authentication and/or authorization request, and replies with an
-   answer, which is routed back to NAS using saved transaction state.
-
-   Since Relays do not perform any application level processing, they
-   provide relaying services for all Diameter applications, and
-   therefore MUST advertise the Relay Application Id.
+   answer, which is routed back to the NAS using saved transaction
+   state.
 
-2.8.2.  Proxy Agents
+   Since relays do not perform any application-level processing, they
+   provide relaying services for all Diameter applications; therefore,
+   they MUST advertise the Relay Application Id.
 
-   Similarly to relays, proxy agents route Diameter messages using the
-   Diameter Routing Table.  However, they differ since they modify
-   messages to implement policy enforcement.  This requires that proxies
-   maintain the state of their downstream peers (e.g., access devices)
-   to enforce resource usage, provide admission control, and
-   provisioning.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 30]
+Fajardo, et al.              Standards Track                   [Page 30]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+2.8.2.  Proxy Agents
+
+   Similar to relays, proxy agents route Diameter messages using the
+   Diameter routing table.  However, they differ since they modify
+   messages to implement policy enforcement.  This requires that proxies
+   maintain the state of their downstream peers (e.g., access devices)
+   to enforce resource usage, provide admission control, and provide
+   provisioning.
 
    Proxies may, for example, be used in call control centers or access
-   ISPs that provide outsourced connections, they can monitor the number
-   and types of ports in use, and make allocation and admission
-   decisions according to their configuration.
+   ISPs that provide outsourced connections; they can monitor the number
+   and type of ports in use and make allocation and admission decisions
+   according to their configuration.
 
    Since enforcing policies requires an understanding of the service
-   being provided, Proxies MUST only advertise the Diameter applications
+   being provided, proxies MUST only advertise the Diameter applications
    they support.
 
 2.8.3.  Redirect Agents
@@ -1709,18 +1721,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
    The example provided in Figure 3 depicts a request issued from the
    access device, NAS, for the user [email protected].  The message is
    forwarded by the NAS to its relay, DRL, which does not have a routing
-   entry in its Diameter Routing Table for example.com.  DRL has a
+   entry in its Diameter routing table for example.com.  The DRL has a
    default route configured to DRD, which is a redirect agent that
-   returns a redirect notification to DRL, as well as HMS' contact
-   information.  Upon receipt of the redirect notification, DRL
-   establishes a transport connection with HMS, if one doesn't already
-   exist, and forwards the request to it.
-
-
-
-
-
-
+   returns a redirect notification to DRL, as well as the HMS' contact
+   information.  Upon receipt of the redirect notification, the DRL
+   establishes a transport connection with the HMS, if one doesn't
+   already exist, and forwards the request to it.
 
 
 
@@ -1729,12 +1735,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 31]
+Fajardo, et al.              Standards Track                   [Page 31]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
                                   +------+
@@ -1755,10 +1758,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
                  Figure 3: Redirecting a Diameter Message
 
-   Since redirect agents do not perform any application level
+   Since redirect agents do not perform any application-level
    processing, they provide relaying services for all Diameter
-   applications, and therefore MUST advertise the Relay Application
-   Identifier.
+   applications; therefore, they MUST advertise the Relay Application
+   ID.
 
 2.8.4.  Translation Agents
 
@@ -1773,7 +1776,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    MUST maintain transaction state.
 
    Translation of messages can only occur if the agent recognizes the
-   application of a particular request, and therefore translation agents
+   application of a particular request; therefore, translation agents
    MUST only advertise their locally supported applications.
 
        +------+    --------->     +------+     --------->    +------+
@@ -1788,23 +1791,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 32]
+Fajardo, et al.              Standards Track                   [Page 32]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 2.9.  Diameter Path Authorization
 
-   As noted in Section 2.2, Diameter provides transmission level
+   As noted in Section 2.2, Diameter provides transmission-level
    security for each connection using TLS/TCP and DTLS/SCTP.  Therefore,
-   each connection can be authenticated, replay and integrity protected.
+   each connection can be authenticated and can be replay and integrity
+   protected.
 
-   In addition to authenticating each connection, each connection as
-   well as the entire session MUST also be authorized.  Before
-   initiating a connection, a Diameter Peer MUST check that its peers
-   are authorized to act in their roles.  For example, a Diameter peer
-   may be authentic, but that does not mean that it is authorized to act
-   as a Diameter Server advertising a set of Diameter applications.
+   In addition to authenticating each connection, the entire session
+   MUST also be authorized.  Before initiating a connection, a Diameter
+   peer MUST check that its peers are authorized to act in their roles.
+   For example, a Diameter peer may be authentic, but that does not mean
+   that it is authorized to act as a Diameter server advertising a set
+   of Diameter applications.
 
    Prior to bringing up a connection, authorization checks are performed
    at each connection along the path.  Diameter capabilities negotiation
@@ -1815,7 +1819,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    As noted in Section 6.1.9, a relay or proxy agent MUST append a
    Route-Record AVP to all requests forwarded.  The AVP contains the
-   identity of the peer the request was received from.
+   identity of the peer from which the request was received.
 
    The home Diameter server, prior to authorizing a session, MUST check
    the Route-Record AVPs to make sure that the route traversed by the
@@ -1823,7 +1827,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    realm may not wish to honor requests that have been routed through an
    untrusted realm.  By authorizing a request, the home Diameter server
    is implicitly indicating its willingness to engage in the business
-   transaction as specified by the contractual relationship between the
+   transaction as specified by any contractual relationship between the
    server and the previous hop.  A DIAMETER_AUTHORIZATION_REJECTED error
    message (see Section 7.1.5) is sent if the route traversed by the
    request is unacceptable.
@@ -1839,72 +1843,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
    willingness to take on financial risk relative to the session.  A
    local realm may wish to limit this exposure, for example, by
    establishing credit limits for intermediate realms and refusing to
-   accept responses which would violate those limits.  By issuing an
-   accounting request corresponding to the authorization response, the
+   accept responses that would violate those limits.  By issuing an
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 33]
+Fajardo, et al.              Standards Track                   [Page 33]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+   accounting request corresponding to the authorization response, the
    local realm implicitly indicates its agreement to provide the service
    indicated in the authorization response.  If the service cannot be
    provided by the local realm, then a DIAMETER_UNABLE_TO_COMPLY error
    message MUST be sent within the accounting request; a Diameter client
    receiving an authorization response for a service that it cannot
-   perform MUST NOT substitute an alternate service, and then send
+   perform MUST NOT substitute an alternate service and then send
    accounting requests for the alternate service instead.
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 34]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 3.  Diameter Header
 
    A summary of the Diameter header format is shown below.  The fields
@@ -1915,7 +1871,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Version    |                 Message Length                |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      | command flags |                  Command-Code                 |
+      | Command Flags |                  Command Code                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         Application-ID                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@@ -1935,13 +1891,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
       The Message Length field is three octets and indicates the length
       of the Diameter message including the header fields and the padded
-      AVPs.  Thus the message length field is always a multiple of 4.
+      AVPs.  Thus, the Message Length field is always a multiple of 4.
 
    Command Flags
 
       The Command Flags field is eight bits.  The following bits are
       assigned:
 
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 34]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
           0 1 2 3 4 5 6 7
          +-+-+-+-+-+-+-+-+
          |R P E T r r r r|
@@ -1952,127 +1918,113 @@ Internet-Draft           Diameter Base Protocol             January 2011
          If set, the message is a request.  If cleared, the message is
          an answer.
 
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 35]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       P(roxiable)
 
-         If set, the message MAY be proxied, relayed or redirected.  If
+         If set, the message MAY be proxied, relayed, or redirected.  If
          cleared, the message MUST be locally processed.
 
-
       E(rror)
 
          If set, the message contains a protocol error, and the message
-         will not conform to the ABNF described for this command.
+         will not conform to the CCF described for this command.
          Messages with the 'E' bit set are commonly referred to as error
-         messages.  This bit MUST NOT be set in request messages.  See
-         Section 7.2.
+         messages.  This bit MUST NOT be set in request messages (see
+         Section 7.2).
 
-
-      T(Potentially re-transmitted message)
+      T(Potentially retransmitted message)
 
          This flag is set after a link failover procedure, to aid the
          removal of duplicate requests.  It is set when resending
          requests not yet acknowledged, as an indication of a possible
          duplicate due to a link failure.  This bit MUST be cleared when
-         sending a request for the first time, otherwise the sender MUST
-         set this flag.  Diameter agents only need to be concerned about
-         the number of requests they send based on a single received
-         request; retransmissions by other entities need not be tracked.
-         Diameter agents that receive a request with the T flag set,
-         MUST keep the T flag set in the forwarded request.  This flag
-         MUST NOT be set if an error answer message (e.g., a protocol
-         error) has been received for the earlier message.  It can be
-         set only in cases where no answer has been received from the
-         server for a request and the request is sent again.  This flag
-         MUST NOT be set in answer messages.
-
+         sending a request for the first time; otherwise, the sender
+         MUST set this flag.  Diameter agents only need to be concerned
+         about the number of requests they send based on a single
+         received request; retransmissions by other entities need not be
+         tracked.  Diameter agents that receive a request with the T
+         flag set, MUST keep the T flag set in the forwarded request.
+         This flag MUST NOT be set if an error answer message (e.g., a
+         protocol error) has been received for the earlier message.  It
+         can be set only in cases where no answer has been received from
+         the server for a request, and the request has been sent again.
+         This flag MUST NOT be set in answer messages.
 
       r(eserved)
 
-         These flag bits are reserved for future use, and MUST be set to
-         zero, and ignored by the receiver.
+         These flag bits are reserved for future use; they MUST be set
+         to zero and ignored by the receiver.
 
-   Command-Code
 
-      The Command-Code field is three octets, and is used in order to
-      communicate the command associated with the message.  The 24-bit
-      address space is managed by IANA (see Section 11.2.1).
 
-      Command-Code values 16,777,214 and 16,777,215 (hexadecimal values
-      FFFFFE -FFFFFF) are reserved for experimental use (See Section
-      11.3).
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 36]
+Fajardo, et al.              Standards Track                   [Page 35]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   Command Code
 
+      The Command Code field is three octets and is used in order to
+      communicate the command associated with the message.  The 24-bit
+      address space is managed by IANA (see Section 3.1).  Command Code
+      values 16,777,214 and 16,777,215 (hexadecimal values FFFFFE-
+      FFFFFF) are reserved for experimental use (see Section 11.2).
 
-    Application-ID
+   Application-ID
 
-      Application-ID is four octets and is used to identify to which
-      application the message is applicable for.  The application can be
-      an authentication application, an accounting application or a
-      vendor specific application.  See Section 11.3 for the possible
-      values that the application-id may use.
+      Application-ID is four octets and is used to identify for which
+      application the message is applicable.  The application can be an
+      authentication application, an accounting application, or a
+      vendor-specific application.
 
-      The value of the application-id field in the header MUST be the
-      same as any relevant application-id AVPs contained in the message.
+      The value of the Application-ID field in the header MUST be the
+      same as any relevant Application-Id AVPs contained in the message.
 
    Hop-by-Hop Identifier
 
       The Hop-by-Hop Identifier is an unsigned 32-bit integer field (in
-      network byte order) and aids in matching requests and replies.
-      The sender MUST ensure that the Hop-by-Hop identifier in a request
-      is unique on a given connection at any given time, and MAY attempt
-      to ensure that the number is unique across reboots.  The sender of
-      an Answer message MUST ensure that the Hop-by-Hop Identifier field
-      contains the same value that was found in the corresponding
-      request.  The Hop-by-Hop identifier is normally a monotonically
-      increasing number, whose start value was randomly generated.  An
-      answer message that is received with an unknown Hop-by-Hop
-      Identifier MUST be discarded.
-
+      network byte order) that aids in matching requests and replies.
+      The sender MUST ensure that the Hop-by-Hop Identifier in a request
+      is unique on a given connection at any given time, and it MAY
+      attempt to ensure that the number is unique across reboots.  The
+      sender of an answer message MUST ensure that the Hop-by-Hop
+      Identifier field contains the same value that was found in the
+      corresponding request.  The Hop-by-Hop Identifier is normally a
+      monotonically increasing number, whose start value was randomly
+      generated.  An answer message that is received with an unknown
+      Hop-by-Hop Identifier MUST be discarded.
 
    End-to-End Identifier
 
       The End-to-End Identifier is an unsigned 32-bit integer field (in
-      network byte order) and is used to detect duplicate messages.
-      Upon reboot implementations MAY set the high order 12 bits to
+      network byte order) that is used to detect duplicate messages.
+      Upon reboot, implementations MAY set the high order 12 bits to
       contain the low order 12 bits of current time, and the low order
       20 bits to a random value.  Senders of request messages MUST
       insert a unique identifier on each message.  The identifier MUST
       remain locally unique for a period of at least 4 minutes, even
-      across reboots.  The originator of an Answer message MUST ensure
+      across reboots.  The originator of an answer message MUST ensure
       that the End-to-End Identifier field contains the same value that
       was found in the corresponding request.  The End-to-End Identifier
       MUST NOT be modified by Diameter agents of any kind.  The
-      combination of the Origin-Host (see Section 6.3) and this field is
+      combination of the Origin-Host AVP (Section 6.3) and this field is
       used to detect duplicates.  Duplicate requests SHOULD cause the
-      same answer to be transmitted (modulo the hop-by-hop Identifier
-      field and any routing AVPs that may be present), and MUST NOT
-      affect any state that was set when the original request was
-      processed.  Duplicate answer messages that are to be locally
-      consumed (see Section 6.2) SHOULD be silently discarded.
-
-
+      same answer to be transmitted (modulo the Hop-by-Hop Identifier
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 37]
+Fajardo, et al.              Standards Track                   [Page 36]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+      field and any routing AVPs that may be present), and they MUST NOT
+      affect any state that was set when the original request was
+      processed.  Duplicate answer messages that are to be locally
+      consumed (see Section 6.2) SHOULD be silently discarded.
+
    AVPs
 
       AVPs are a method of encapsulating information relevant to the
@@ -2080,17 +2032,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 3.1.  Command Codes
 
-   Each command Request/Answer pair is assigned a command code, and the
+   Each command Request/Answer pair is assigned a Command Code, and the
    sub-type (i.e., request or answer) is identified via the 'R' bit in
    the Command Flags field of the Diameter header.
 
-
-   Every Diameter message MUST contain a command code in its header's
-   Command-Code field, which is used to determine the action that is to
+   Every Diameter message MUST contain a Command Code in its header's
+   Command Code field, which is used to determine the action that is to
    be taken for a particular message.  The following Command Codes are
    defined in the Diameter base protocol:
 
-    Command-Name             Abbrev.    Code       Reference
+                                                   Section
+    Command Name             Abbrev.    Code       Reference
       --------------------------------------------------------
       Abort-Session-Request     ASR       274           8.5.1
       Abort-Session-Answer      ASA       274           8.5.2
@@ -2111,140 +2063,142 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Session-Termination-      STA       275           8.4.2
          Answer
 
-3.2.  Command Code ABNF specification
 
-   Every Command Code defined MUST include a corresponding ABNF
-   specification, which is used to define the AVPs that MUST or MAY be
-   present when sending the message.  The following format is used in
-   the definition:
 
-  command-def      = <command-name> "::=" diameter-message
 
-  command-name     = diameter-name
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 38]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-  diameter-name    = ALPHA *(ALPHA / DIGIT / "-")
+Fajardo, et al.              Standards Track                   [Page 37]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-  diameter-message = header  [ *fixed] [ *required] [ *optional]
 
-  header           = "<" "Diameter Header:" command-id
-                     [r-bit] [p-bit] [e-bit] [application-id] ">"
+3.2.  Command Code Format Specification
 
-  application-id   = 1*DIGIT
+   Every Command Code defined MUST include a corresponding Command Code
+   Format (CCF) specification, which is used to define the AVPs that
+   MUST or MAY be present when sending the message.  The following ABNF
+   specifies the CCF used in the definition:
 
-  command-id       = 1*DIGIT
-                     ; The Command Code assigned to the command
+   command-def      = "<" command-name ">" "::=" diameter-message
 
-  r-bit            = ", REQ"
-                     ; If present, the 'R' bit in the Command
-                     ; Flags is set, indicating that the message
-                     ; is a request, as opposed to an answer.
+   command-name     = diameter-name
 
-  p-bit            = ", PXY"
-                     ; If present, the 'P' bit in the Command
-                     ; Flags is set, indicating that the message
-                     ; is proxiable.
+   diameter-name    = ALPHA *(ALPHA / DIGIT / "-")
 
-  e-bit            = ", ERR"
-                     ; If present, the 'E' bit in the Command
-                     ; Flags is set, indicating that the answer
-                     ; message contains a Result-Code AVP in
-                     ; the "protocol error" class.
+   diameter-message = header   *fixed  *required *optional
 
-  fixed            = [qual] "<" avp-spec ">"
-                     ; Defines the fixed position of an AVP
+   header           = "<Diameter-Header:" command-id
+                         [r-bit] [p-bit] [e-bit] [application-id]">"
 
-  required         = [qual] "{" avp-spec "}"
-                     ; The AVP MUST be present and can appear
-                     ; anywhere in the message.
+   application-id   = 1*DIGIT
 
+   command-id       = 1*DIGIT
+                      ; The Command Code assigned to the command.
 
-  optional         = [qual] "[" avp-name "]"
-                     ; The avp-name in the 'optional' rule cannot
-                     ; evaluate to any AVP Name which is included
-                     ; in a fixed or required rule.  The AVP can
-                     ; appear anywhere in the message.
-                     ;
-                     ; NOTE:  "[" and "]" have a slightly different
-                     ; meaning than in ABNF (RFC 5234]). These braces
-                     ; cannot be used to express optional fixed rules
-                     ; (such as an optional ICV at the end). To do this,
-                     ; the convention is '0*1fixed'.
+   r-bit            = ", REQ"
+                      ; If present, the 'R' bit in the Command
+                      ; Flags is set, indicating that the message
+                      ; is a request as opposed to an answer.
 
+   p-bit            = ", PXY"
+                      ; If present, the 'P' bit in the Command
+                      ; Flags is set, indicating that the message
+                      ; is proxiable.
 
+   e-bit            = ", ERR"
+                      ; If present, the 'E' bit in the Command
+                      ; Flags is set, indicating that the answer
+                      ; message contains a Result-Code AVP in
+                      ; the "protocol error" class.
 
+   fixed            = [qual] "<" avp-spec ">"
+                      ; Defines the fixed position of an AVP.
 
-Fajardo, et al.           Expires July 24, 2011                [Page 39]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   required         = [qual] "{" avp-spec "}"
+                      ; The AVP MUST be present and can appear
+                      ; anywhere in the message.
 
 
-  qual             = [min] "*" [max]
-                     ; See ABNF conventions, RFC 5234 Section 4.
-                     ; The absence of any qualifiers depends on
-                     ; whether it precedes a fixed, required, or
-                     ; optional rule. If a fixed or required rule has
-                     ; no qualifier, then exactly one such AVP MUST
-                     ; be present.  If an optional rule has no
-                     ; qualifier, then 0 or 1 such AVP may be
-                     ; present. If an optional rule has a qualifier,
-                     ; then the value of min MUST be 0 if present.
 
-  min              = 1*DIGIT
-                     ; The minimum number of times the element may
-                     ; be present. If absent, the default value is zero
-                     ; for fixed and optional rules and one for required
-                     ; rules. The value MUST be at least one for for
-                     ; required rules.
 
-  max              = 1*DIGIT
-                     ; The maximum number of times the element may
-                     ; be present. If absent, the default value is
-                     ; infinity. A value of zero implies the AVP MUST
-                     ; NOT be present.
 
-  avp-spec         = diameter-name
-                     ; The avp-spec has to be an AVP Name, defined
-                     ; in the base or extended Diameter
-                     ; specifications.
-
-  avp-name         = avp-spec / "AVP"
-                     ; The string "AVP" stands for *any* arbitrary AVP
-                     ; Name, not otherwise listed in that command code
-                     ; definition. Addition this AVP is recommended for
-                     ; all command ABNFs to allow for extensibility.
 
+Fajardo, et al.              Standards Track                   [Page 38]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-  The following is a definition of a fictitious command code:
+   optional         = [qual] "[" avp-name "]"
+                      ; The avp-name in the 'optional' rule cannot
+                      ; evaluate to any AVP Name that is included
+                      ; in a fixed or required rule.  The AVP can
+                      ; appear anywhere in the message.
+                      ;
+                      ; NOTE:  "[" and "]" have a slightly different
+                      ; meaning than in ABNF.  These braces
+                      ; cannot be used to express optional fixed rules
+                      ; (such as an optional ICV at the end).  To do
+                      ; this, the convention is '0*1fixed'.
 
-  Example-Request ::= < Diameter Header: 9999999, REQ, PXY >
-                      { User-Name }
-                    * { Origin-Host }
-                    * [ AVP ]
+   qual             = [min] "*" [max]
+                      ; See ABNF conventions, RFC 5234, Section 4.
+                      ; The absence of any qualifier depends on
+                      ; whether it precedes a fixed, required, or
+                      ; optional rule.  If a fixed or required rule has
+                      ; no qualifier, then exactly one such AVP MUST
+                      ; be present.  If an optional rule has no
+                      ; qualifier, then 0 or 1 such AVP may be
+                      ; present.  If an optional rule has a qualifier,
+                      ; then the value of min MUST be 0 if present.
 
+   min              = 1*DIGIT
+                      ; The minimum number of times the element may
+                      ; be present.  If absent, the default value is 0
+                      ; for fixed and optional rules and 1 for
+                      ; required rules.  The value MUST be at least 1
+                      ; for required rules.
 
+   max              = 1*DIGIT
+                      ; The maximum number of times the element may
+                      ; be present.  If absent, the default value is
+                      ; infinity.  A value of 0 implies the AVP MUST
+                      ; NOT be present.
 
+   avp-spec         = diameter-name
+                      ; The avp-spec has to be an AVP Name, defined
+                      ; in the base or extended Diameter
+                      ; specifications.
 
+   avp-name         = avp-spec / "AVP"
+                      ; The string "AVP" stands for *any* arbitrary AVP
+                      ; Name, not otherwise listed in that Command Code
+                      ; definition.  The inclusion of this string
+                      ; is recommended for all CCFs to allow for
+                      ; extensibility.
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 40]
+Fajardo, et al.              Standards Track                   [Page 39]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   The following is a definition of a fictitious Command Code:
 
+   Example-Request ::= < Diameter Header: 9999999, REQ, PXY >
+                       { User-Name }
+                    1* { Origin-Host }
+                     * [ AVP ]
 
 3.3.  Diameter Command Naming Conventions
 
    Diameter command names typically includes one or more English words
-   followed by the verb Request or Answer.  Each English word is
+   followed by the verb "Request" or "Answer".  Each English word is
    delimited by a hyphen.  A three-letter acronym for both the request
    and answer is also normally provided.
 
@@ -2253,10 +2207,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the acronyms are STR and STA, respectively.
 
    Both the request and the answer for a given command share the same
-   command code.  The request is identified by the R(equest) bit in the
+   Command Code.  The request is identified by the R(equest) bit in the
    Diameter header set to one (1), to ask that a particular action be
    performed, such as authorizing a user or terminating a session.  Once
-   the receiver has completed the request it issues the corresponding
+   the receiver has completed the request, it issues the corresponding
    answer, which includes a result code that communicates one of the
    following:
 
@@ -2274,38 +2228,25 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Additional information, encoded within AVPs, may also be included in
    answer messages.
 
+4.  Diameter AVPs
 
+   Diameter AVPs carry specific authentication, accounting,
+   authorization, and routing information as well as configuration
+   details for the request and reply.
 
 
 
 
 
 
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 41]
+Fajardo, et al.              Standards Track                   [Page 40]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-4.  Diameter AVPs
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   Diameter AVPs carry specific authentication, accounting,
-   authorization and routing information as well as configuration
-   details for the request and reply.
 
    Each AVP of type OctetString MUST be padded to align on a 32-bit
    boundary, while other AVP types align naturally.  A number of zero-
-   valued bytes are added to the end of the AVP Data field till a word
+   valued bytes are added to the end of the AVP Data field until a word
    boundary is reached.  The length of the padding is not reflected in
    the AVP Length field.
 
@@ -2330,92 +2271,96 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
       The AVP Code, combined with the Vendor-Id field, identifies the
       attribute uniquely.  AVP numbers 1 through 255 are reserved for
-      re-use of RADIUS attributes, without setting the Vendor-Id field.
+      reuse of RADIUS attributes, without setting the Vendor-Id field.
       AVP numbers 256 and above are used for Diameter, which are
-      allocated by IANA (see Section 11.1).
-
+      allocated by IANA (see Section 11.1.1).
 
    AVP Flags
 
       The AVP Flags field informs the receiver how each attribute must
-      be handled.  The 'r' (reserved) bits are unused and SHOULD be set
-      to 0.  Note that subsequent Diameter applications MAY define
-      additional bits within the AVP Header, and an unrecognized bit
-      SHOULD be considered an error.  The 'P' bit has been reserved for
-      future usage of end-to-end security.  At the time of writing there
-      are no end-to-end security mechanisms specified therefore the 'P'
-      bit SHOULD be set to 0.
+      be handled.  New Diameter applications SHOULD NOT define
+      additional AVP Flag bits.  However, note that new Diameter
+      applications MAY define additional bits within the AVP header, and
+      an unrecognized bit SHOULD be considered an error.  The sender of
+      the AVP MUST set 'R' (reserved) bits to 0 and the receiver SHOULD
+      ignore all 'R' (reserved) bits.  The 'P' bit has been reserved for
+      future usage of end-to-end security.  At the time of writing,
+      there are no end-to-end security mechanisms specified; therefore,
+      the 'P' bit SHOULD be set to 0.
+
+      The 'M' bit, known as the Mandatory bit, indicates whether the
+      receiver of the AVP MUST parse and understand the semantics of the
+      AVP including its content.  The receiving entity MUST return an
+      appropriate error message if it receives an AVP that has the M-bit
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 42]
+Fajardo, et al.              Standards Track                   [Page 41]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-      The 'M' Bit, known as the Mandatory bit, indicates whether the
-      receiver of the AVP MUST parse and understand the semantic of the
-      AVP including its content.  The receiving entity MUST return an
-      appropriate error message if it receives an AVP that has the M-bit
       set but does not understand it.  An exception applies when the AVP
       is embedded within a Grouped AVP.  See Section 4.4 for details.
-      Diameter Relay and redirect agents MUST NOT reject messages with
+      Diameter relay and redirect agents MUST NOT reject messages with
       unrecognized AVPs.
 
       The 'M' bit MUST be set according to the rules defined in the
-      application specification which introduces or re-uses this AVP.
-      Within a given application, the M-bit setting for an AVP is either
-      defined for all command types or for each command type.
+      application specification that introduces or reuses this AVP.
+      Within a given application, the M-bit setting for an AVP is
+      defined either for all command types or for each command type.
 
-      AVPs with the 'M' bit cleared are informational only and a
-      receiver that receives a message with such an AVP that is not
-      supported, or whose value is not supported, MAY simply ignore the
-      AVP.
+      AVPs with the 'M' bit cleared are informational only; a receiver
+      that receives a message with such an AVP that is not supported, or
+      whose value is not supported, MAY simply ignore the AVP.
 
       The 'V' bit, known as the Vendor-Specific bit, indicates whether
       the optional Vendor-ID field is present in the AVP header.  When
-      set the AVP Code belongs to the specific vendor code address
+      set, the AVP Code belongs to the specific vendor code address
       space.
 
    AVP Length
 
       The AVP Length field is three octets, and indicates the number of
-      octets in this AVP including the AVP Code, AVP Length, AVP Flags,
-      Vendor-ID field (if present) and the AVP data.  If a message is
-      received with an invalid attribute length, the message MUST be
-      rejected.
+      octets in this AVP including the AVP Code field, AVP Length field,
+      AVP Flags field, Vendor-ID field (if present), and the AVP Data
+      field.  If a message is received with an invalid attribute length,
+      the message MUST be rejected.
 
 4.1.1.  Optional Header Elements
 
-   The AVP Header contains one optional field.  This field is only
+   The AVP header contains one optional field.  This field is only
    present if the respective bit-flag is enabled.
 
-
    Vendor-ID
 
       The Vendor-ID field is present if the 'V' bit is set in the AVP
       Flags field.  The optional four-octet Vendor-ID field contains the
-      IANA assigned "SMI Network Management Private Enterprise Codes"
-      [RFC3232] value, encoded in network byte order.  Any vendor or
-      standardization organization that are also treated like vendors in
-      the IANA managed "SMI Network Management Private Enterprise Codes"
-      space wishing to implement a vendor-specific Diameter AVP MUST use
-      their own Vendor-ID along with their privately managed AVP address
+      IANA-assigned "SMI Network Management Private Enterprise Codes"
+      [ENTERPRISE] value, encoded in network byte order.  Any vendors or
+      standardization organizations that are also treated like vendors
+      in the IANA-managed "SMI Network Management Private Enterprise
+      Codes" space wishing to implement a vendor-specific Diameter AVP
+      MUST use their own Vendor-ID along with their privately managed
+      AVP address space, guaranteeing that they will not collide with
+      any other vendor's vendor-specific AVP(s) or with future IETF
+      AVPs.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 43]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-      space, guaranteeing that they will not collide with any other
-      vendor's vendor-specific AVP(s), nor with future IETF AVPs.
 
-      A vendor ID value of zero (0) corresponds to the IETF adopted AVP
-      values, as managed by the IANA.  Since the absence of the vendor
-      ID field implies that the AVP in question is not vendor specific,
-      implementations MUST NOT use the zero (0) vendor ID.
+Fajardo, et al.              Standards Track                   [Page 42]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+      A Vendor-ID value of zero (0) corresponds to the IETF-adopted AVP
+      values, as managed by IANA.  Since the absence of the Vendor-ID
+      field implies that the AVP in question is not vendor specific,
+      implementations MUST NOT use the value of zero (0) for the
+      Vendor-ID field.
 
 4.2.  Basic AVP Data Formats
 
@@ -2426,49 +2371,45 @@ Internet-Draft           Diameter Base Protocol             January 2011
    type derived from the base data types.  In the event that a new Basic
    AVP Data Format is needed, a new version of this RFC MUST be created.
 
-
    OctetString
 
       The data contains arbitrary data of variable length.  Unless
       otherwise noted, the AVP Length field MUST be set to at least 8
-      (12 if the 'V' bit is enabled).  AVP Values of this type that are
-      not a multiple of four-octets in length is followed by the
-      necessary padding so that the next AVP (if any) will start on a
-      32-bit boundary.
-
+      (12 if the 'V' bit is enabled).  AVP values of this type that are
+      not a multiple of 4 octets in length are followed by the necessary
+      padding so that the next AVP (if any) will start on a 32-bit
+      boundary.
 
    Integer32
 
-      32 bit signed value, in network byte order.  The AVP Length field
+      32-bit signed value, in network byte order.  The AVP Length field
       MUST be set to 12 (16 if the 'V' bit is enabled).
 
-
    Integer64
 
-      64 bit signed value, in network byte order.  The AVP Length field
+      64-bit signed value, in network byte order.  The AVP Length field
       MUST be set to 16 (20 if the 'V' bit is enabled).
 
-
    Unsigned32
 
-      32 bit unsigned value, in network byte order.  The AVP Length
+      32-bit unsigned value, in network byte order.  The AVP Length
       field MUST be set to 12 (16 if the 'V' bit is enabled).
 
+   Unsigned64
 
+      64-bit unsigned value, in network byte order.  The AVP Length
+      field MUST be set to 16 (20 if the 'V' bit is enabled).
 
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 44]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-   Unsigned64
 
-      64 bit unsigned value, in network byte order.  The AVP Length
-      field MUST be set to 16 (20 if the 'V' bit is enabled).
+Fajardo, et al.              Standards Track                   [Page 43]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Float32
@@ -2478,7 +2419,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
       network byte order.  The AVP Length field MUST be set to 12 (16 if
       the 'V' bit is enabled).
 
-
    Float64
 
       This represents floating point values of double precision as
@@ -2486,73 +2426,69 @@ Internet-Draft           Diameter Base Protocol             January 2011
       network byte order.  The AVP Length field MUST be set to 16 (20 if
       the 'V' bit is enabled).
 
-
    Grouped
 
-      The Data field is specified as a sequence of AVPs.  Each of these
-      AVPs follows - in the order in which they are specified -
-      including their headers and padding.  The AVP Length field is set
-      to 8 (12 if the 'V' bit is enabled) plus the total length of all
-      included AVPs, including their headers and padding.  Thus the AVP
-      length field of an AVP of type Grouped is always a multiple of 4.
-
+      The Data field is specified as a sequence of AVPs.  These AVPs are
+      concatenated -- including their headers and padding -- in the
+      order in which they are specified and the result encapsulated in
+      the Data field.  The AVP Length field is set to 8 (12 if the 'V'
+      bit is enabled) plus the total length of all included AVPs,
+      including their headers and padding.  Thus, the AVP Length field
+      of an AVP of type Grouped is always a multiple of 4.
 
 4.3.  Derived AVP Data Formats
 
    In addition to using the Basic AVP Data Formats, applications may
    define data formats derived from the Basic AVP Data Formats.  An
    application that defines new Derived AVP Data Formats MUST include
-   them in a section entitled "Derived AVP Data Formats", using the same
+   them in a section titled "Derived AVP Data Formats", using the same
    format as the definitions below.  Each new definition MUST be either
    defined or listed with a reference to the RFC that defines the
    format.
 
-4.3.1.  Common Derived AVPs
+4.3.1.  Common Derived AVP Data Formats
 
    The following are commonly used Derived AVP Data Formats.
 
+   Address
 
+      The Address format is derived from the OctetString Basic AVP
+      Format.  It is a discriminated union representing, for example, a
+      32-bit (IPv4) [RFC0791] or 128-bit (IPv6) [RFC4291] address, most
+      significant octet first.  The first two octets of the Address AVP
+      represent the AddressType, which contains an Address Family,
+      defined in [IANAADFAM].  The AddressType is used to discriminate
+      the content and format of the remaining octets.
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 45]
+Fajardo, et al.              Standards Track                   [Page 44]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-   Address
-
-      The Address format is derived from the OctetString AVP Base
-      Format.  It is a discriminated union, representing, for example a
-      32-bit (IPv4) [RFC791] or 128-bit (IPv6) [RFC4291] address, most
-      significant octet first.  The first two octets of the Address AVP
-      represents the AddressType, which contains an Address Family
-      defined in [IANAADFAM].  The AddressType is used to discriminate
-      the content and format of the remaining octets.
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Time
 
-      The Time format is derived from the OctetString AVP Base Format.
+      The Time format is derived from the OctetString Basic AVP Format.
       The string MUST contain four octets, in the same format as the
       first four bytes are in the NTP timestamp format.  The NTP
-      Timestamp format is defined in Chapter 3 of [RFC5905].
+      timestamp format is defined in Section 3 of [RFC5905].
 
       This represents the number of seconds since 0h on 1 January 1900
       with respect to the Coordinated Universal Time (UTC).
 
-      On 6h 28m 16s UTC, 7 February 2036 the time value will overflow.
-      SNTP [RFC5905] describes a procedure to extend the time to 2104.
-      This procedure MUST be supported by all Diameter nodes.
-
+      On 6h 28m 16s UTC, 7 February 2036, the time value will overflow.
+      Simple Network Time Protocol (SNTP) [RFC5905] describes a
+      procedure to extend the time to 2104.  This procedure MUST be
+      supported by all Diameter nodes.
 
    UTF8String
 
-      The UTF8String format is derived from the OctetString AVP Base
-      Format.  This is a human readable string represented using the
+      The UTF8String format is derived from the OctetString Basic AVP
+      Format.  This is a human-readable string represented using the
       ISO/IEC IS 10646-1 character set, encoded as an OctetString using
-      the UTF-8 [RFC3629] transformation format described in RFC 3629.
+      the UTF-8 transformation format [RFC3629].
 
       Since additional code points are added by amendments to the 10646
       standard from time to time, implementations MUST be prepared to
@@ -2570,78 +2506,79 @@ Internet-Draft           Diameter Base Protocol             January 2011
       or software, an alternative means of entry and display, such as
       hexadecimal, MAY be provided.
 
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 46]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       For information encoded in 7-bit US-ASCII, the UTF-8 charset is
       identical to the US-ASCII charset.
 
       UTF-8 may require multiple bytes to represent a single character /
-      code point; thus the length of an UTF8String in octets may be
+      code point; thus, the length of a UTF8String in octets may be
       different from the number of characters encoded.
 
       Note that the AVP Length field of an UTF8String is measured in
-      octets, not characters.
+      octets not characters.
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 45]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    DiameterIdentity
 
-      The DiameterIdentity format is derived from the OctetString AVP
-      Base Format.
+      The DiameterIdentity format is derived from the OctetString Basic
+      AVP Format.
 
                         DiameterIdentity  = FQDN/Realm
 
-
-      DiameterIdentity value is used to uniquely identify either:
+   The DiameterIdentity value is used to uniquely identify either:
 
       *  A Diameter node for purposes of duplicate connection and
          routing loop detection.
 
-      *  A Realm to determine whether messages can be satisfied locally,
+      *  A Realm to determine whether messages can be satisfied locally
          or whether they must be routed or redirected.
 
+      When a DiameterIdentity value is used to identify a Diameter node,
+      the contents of the string MUST be the Fully Qualified Domain Name
+      (FQDN) of the Diameter node.  If multiple Diameter nodes run on
+      the same host, each Diameter node MUST be assigned a unique
+      DiameterIdentity.  If a Diameter node can be identified by several
+      FQDNs, a single FQDN should be picked at startup and used as the
+      only DiameterIdentity for that node, whatever the connection on
+      which it is sent.  In this document, note that DiameterIdentity is
+      in ASCII form in order to be compatible with existing DNS
+      infrastructure.  See Appendix D for interactions between the
+      Diameter protocol and Internationalized Domain Names (IDNs).
 
-      When a DiameterIdentity is used to identify a Diameter node the
-      contents of the string MUST be the FQDN of the Diameter node.  If
-      multiple Diameter nodes run on the same host, each Diameter node
-      MUST be assigned a unique DiameterIdentity.  If a Diameter node
-      can be identified by several FQDNs, a single FQDN should be picked
-      at startup, and used as the only DiameterIdentity for that node,
-      whatever the connection it is sent on.  Note that in this
-      document, DiameterIdentity is in ASCII form in order to be
-      compatible with existing DNS infrastructure.  See Appendix D for
-      interactions between the Diameter protocol and Internationalized
-      Domain Name (IDNs).
+   DiameterURI
 
+      The DiameterURI MUST follow the Uniform Resource Identifiers (RFC
+      3986) syntax [RFC3986] rules specified below:
 
-   DiameterURI
+      "aaa://" FQDN [ port ] [ transport ] [ protocol ]
 
-      The DiameterURI MUST follow the Uniform Resource Identifiers (URI)
-      syntax [RFC3986] rules specified below:
+                      ; No transport security
 
+      "aaas://" FQDN [ port ] [ transport ] [ protocol ]
 
+                      ; Transport security used
 
+      FQDN               = < Fully Qualified Domain Name >
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 47]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-      "aaa://" FQDN [ port ] [ transport ] [ protocol ]
 
-                      ; No transport security
 
-      "aaas://" FQDN [ port ] [ transport ] [ protocol ]
 
-                      ; Transport security used
 
-      FQDN               = Fully Qualified Host Name
+Fajardo, et al.              Standards Track                   [Page 46]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
       port               = ":" 1*DIGIT
 
@@ -2649,8 +2586,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
                       ; incoming connections.
                       ; If absent, the default Diameter port
                       ; (3868) is assumed if no transport
-                      ; security is used and port (TBD) when
-                      ; transport security (TLS/TCP and DTLS/SCTP) is used.
+                      ; security is used and port 5658 when
+                      ; transport security (TLS/TCP and DTLS/SCTP)
+                      ; is used.
 
       transport          = ";transport=" transport-protocol
 
@@ -2660,46 +2598,47 @@ Internet-Draft           Diameter Base Protocol             January 2011
                       ; UDP MUST NOT be used when the aaa-protocol
                       ; field is set to diameter.
 
-    transport-protocol = ( "tcp" / "sctp" / "udp" )
+      transport-protocol = ( "tcp" / "sctp" / "udp" )
 
-    protocol           = ";protocol=" aaa-protocol
+      protocol           = ";protocol=" aaa-protocol
 
                       ; If absent, the default AAA protocol
                       ; is Diameter.
 
-    aaa-protocol       = ( "diameter" / "radius" / "tacacs+" )
+      aaa-protocol       = ( "diameter" / "radius" / "tacacs+" )
 
-    The following are examples of valid Diameter host identities:
+      The following are examples of valid Diameter host identities:
 
-    aaa://host.example.com;transport=tcp
-    aaa://host.example.com:6666;transport=tcp
-    aaa://host.example.com;protocol=diameter
-    aaa://host.example.com:6666;protocol=diameter
-    aaa://host.example.com:6666;transport=tcp;protocol=diameter
-    aaa://host.example.com:1813;transport=udp;protocol=radius
+      aaa://host.example.com;transport=tcp
+      aaa://host.example.com:6666;transport=tcp
+      aaa://host.example.com;protocol=diameter
+      aaa://host.example.com:6666;protocol=diameter
+      aaa://host.example.com:6666;transport=tcp;protocol=diameter
+      aaa://host.example.com:1813;transport=udp;protocol=radius
 
+   Enumerated
 
+      The Enumerated format is derived from the Integer32 Basic AVP
+      Format.  The definition contains a list of valid values and their
+      interpretation and is described in the Diameter application
+      introducing the AVP.
 
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 48]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-   Enumerated
 
-      Enumerated is derived from the Integer32 AVP Base Format.  The
-      definition contains a list of valid values and their
-      interpretation and is described in the Diameter application
-      introducing the AVP.
+
+Fajardo, et al.              Standards Track                   [Page 47]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    IPFilterRule
 
-      The IPFilterRule format is derived from the OctetString AVP Base
+      The IPFilterRule format is derived from the OctetString Basic AVP
       Format and uses the ASCII charset.  The rule syntax is a modified
       subset of ipfw(8) from FreeBSD.  Packets may be filtered based on
       the following information that is associated with it:
@@ -2713,13 +2652,13 @@ Internet-Draft           Diameter Base Protocol             January 2011
             IP options
             ICMP types
 
-      Rules for the appropriate direction are evaluated in order, with
-      the first matched rule terminating the evaluation.  Each packet is
-      evaluated once.  If no rule matches, the packet is dropped if the
-      last rule evaluated was a permit, and passed if the last rule was
-      a deny.
+   Rules for the appropriate direction are evaluated in order, with the
+   first matched rule terminating the evaluation.  Each packet is
+   evaluated once.  If no rule matches, the packet is dropped if the
+   last rule evaluated was a permit, and passed if the last rule was a
+   deny.
 
-      IPFilterRule filters MUST follow the format:
+   IPFilterRule filters MUST follow the format:
 
          action dir proto from src to dst [options]
 
@@ -2737,22 +2676,28 @@ Internet-Draft           Diameter Base Protocol             January 2011
                       The <address/mask> may be specified as:
                       ipno       An IPv4 or IPv6 number in dotted-
                                  quad or canonical IPv6 form.  Only
+                                 this exact IP number will match the
+                                 rule.
+
+
+
+
+
+
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 49]
+Fajardo, et al.              Standards Track                   [Page 48]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-                                 this exact IP number will match the
-                                 rule.
                       ipno/bits  An IP number as above with a mask
                                  width of the form 192.0.2.10/24.  In
                                  this case, all IP numbers from
                                  192.0.2.0 to 192.0.2.255 will match.
                                  The bit width MUST be valid for the
-                                 IP version and the IP number MUST
+                                 IP version, and the IP number MUST
                                  NOT have bits set beyond the mask.
                                  For a match to occur, the same IP
                                  version must be present in the
@@ -2765,7 +2710,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
                                  is the address or set of addresses
                                  assigned to the terminal.  For IPv4,
                                  a typical first rule is often "deny
-                                 in ip! assigned"
+                                 in ip! assigned".
 
                       The sense of the match can be inverted by
                       preceding an address with the not modifier (!),
@@ -2773,7 +2718,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
                       instead.  This does not affect the selection of
                       port numbers.
 
-                      With the TCP, UDP and SCTP protocols, optional
+                      With the TCP, UDP, and SCTP protocols, optional
                       ports may be specified as:
 
                          {port/port-port}[,ports[,...]]
@@ -2796,33 +2741,35 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 50]
+
+
+Fajardo, et al.              Standards Track                   [Page 49]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-             ipoptions spec
-                    Match if the IP header contains the comma
-                    separated list of options specified in spec.  The
+            ipoptions spec
+                    Match if the IP header contains the comma-separated
+                    list of options specified in spec.  The
                     supported IP options are:
 
                     ssrr (strict source route), lsrr (loose source
-                    route), rr (record packet route) and ts
+                    route), rr (record packet route), and ts
                     (timestamp).  The absence of a particular option
                     may be denoted with a '!'.
 
             tcpoptions spec
-                    Match if the TCP header contains the comma
-                    separated list of options specified in spec.  The
+                    Match if the TCP header contains the comma-separated
+                    list of options specified in spec.  The
                     supported TCP options are:
 
                     mss (maximum segment size), window (tcp window
                     advertisement), sack (selective ack), ts (rfc1323
-                    timestamp) and cc (rfc1644 t/tcp connection
+                    timestamp), and cc (rfc1644 t/tcp connection
                     count).  The absence of a particular option may
                     be denoted with a '!'.
 
-             established
+            established
                     TCP packets only.  Match packets that have the RST
                     or ACK bits set.
 
@@ -2832,10 +2779,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
             tcpflags spec
                     TCP packets only.  Match if the TCP header
-                    contains the comma separated list of flags
+                    contains the comma-separated list of flags
                     specified in spec.  The supported TCP flags are:
 
-                    fin, syn, rst, psh, ack and urg.  The absence of a
+                    fin, syn, rst, psh, ack, and urg.  The absence of a
                     particular flag may be denoted with a '!'.  A rule
                     that contains a tcpflags specification can never
                     match a fragmented packet that has a non-zero
@@ -2852,9 +2799,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 51]
+Fajardo, et al.              Standards Track                   [Page 50]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
                     echo reply (0), destination unreachable (3),
@@ -2863,21 +2810,20 @@ Internet-Draft           Diameter Base Protocol             January 2011
                     solicitation (10), time-to-live exceeded (11), IP
                     header bad (12), timestamp request (13),
                     timestamp reply (14), information request (15),
-                    information reply (16), address mask request (17)
+                    information reply (16), address mask request (17),
                     and address mask reply (18).
 
-      There is one kind of packet that the access device MUST always
-      discard, that is an IP fragment with a fragment offset of one.
-      This is a valid packet, but it only has one use, to try to
-      circumvent firewalls.
-
-      An access device that is unable to interpret or apply a deny rule
-      MUST terminate the session.  An access device that is unable to
-      interpret or apply a permit rule MAY apply a more restrictive
-      rule.  An access device MAY apply deny rules of its own before the
-      supplied rules, for example to protect the access device owner's
-      infrastructure.
+   There is one kind of packet that the access device MUST always
+   discard, that is an IP fragment with a fragment offset of one.  This
+   is a valid packet, but it only has one use, to try to circumvent
+   firewalls.
 
+   An access device that is unable to interpret or apply a deny rule
+   MUST terminate the session.  An access device that is unable to
+   interpret or apply a permit rule MAY apply a more restrictive rule.
+   An access device MAY apply deny rules of its own before the supplied
+   rules, for example to protect the access device owner's
+   infrastructure.
 
 4.4.   Grouped AVP Values
 
@@ -2885,75 +2831,76 @@ Internet-Draft           Diameter Base Protocol             January 2011
    implies that the Data field is actually a sequence of AVPs.  It is
    possible to include an AVP with a Grouped type within a Grouped type,
    that is, to nest them.  AVPs within an AVP of type Grouped have the
-   same padding requirements as non-Grouped AVPs, as defined in Section
-   4.
+   same padding requirements as non-Grouped AVPs, as defined in
+   Section 4.4.
 
    The AVP Code numbering space of all AVPs included in a Grouped AVP is
-   the same as for non-grouped AVPs.  Receivers of a Grouped AVP that
+   the same as for non-Grouped AVPs.  Receivers of a Grouped AVP that
    does not have the 'M' (mandatory) bit set and one or more of the
    encapsulated AVPs within the group has the 'M' (mandatory) bit set
    MAY simply be ignored if the Grouped AVP itself is unrecognized.  The
    rule applies even if the encapsulated AVP with its 'M' (mandatory)
-   bit set is further encapsulated within other sub-groups; i.e. other
+   bit set is further encapsulated within other sub-groups, i.e., other
    Grouped AVPs embedded within the Grouped AVP.
 
-   Every Grouped AVP defined MUST include a corresponding grammar, using
-   ABNF [RFC5234] (with modifications), as defined below.
-
+   Every Grouped AVP definition MUST include a corresponding grammar,
+   using ABNF [RFC5234] (with modifications), as defined below.
 
+         grouped-avp-def  = "<" name ">" "::=" avp
 
+         name-fmt         = ALPHA *(ALPHA / DIGIT / "-")
 
 
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 52]
+Fajardo, et al.              Standards Track                   [Page 51]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-                            grouped-avp-def  = <name> "::=" avp
-
-         name-fmt         = ALPHA *(ALPHA / DIGIT / "-")
-
          name             = name-fmt
                             ; The name has to be the name of an AVP,
                             ; defined in the base or extended Diameter
                             ; specifications.
 
-         avp              = header  [ *fixed] [ *required] [ *optional]
+         avp              = header *fixed *required *optional
 
          header           = "<" "AVP-Header:" avpcode [vendor] ">"
 
          avpcode          = 1*DIGIT
-                            ; The AVP Code assigned to the Grouped AVP
+                            ; The AVP Code assigned to the Grouped AVP.
 
          vendor           = 1*DIGIT
                             ; The Vendor-ID assigned to the Grouped AVP.
                             ; If absent, the default value of zero is
                             ; used.
 
-4.4.1.  Example AVP with a Grouped Data type
+4.4.1.  Example AVP with a Grouped Data Type
 
    The Example-AVP (AVP Code 999999) is of type Grouped and is used to
    clarify how Grouped AVP values work.  The Grouped Data field has the
-   following ABNF grammar:
-
-
-
-
-
-
-
-
+   following CCF grammar:
 
+         Example-AVP  ::= < AVP Header: 999999 >
+                          { Origin-Host }
+                        1*{ Session-Id }
+                         *[ AVP ]
 
+      An Example-AVP with Grouped Data follows.
 
+      The Origin-Host AVP (Section 6.3) is required.  In this case:
 
+         Origin-Host = "example.com".
 
+      One or more Session-Ids must follow.  Here there are two:
 
+         Session-Id =
+           "grump.example.com:33041;23432;893;0AF3B81"
 
+         Session-Id =
+           "grump.example.com:33054;23561;2358;0AF3B82"
 
 
 
@@ -2964,31 +2911,11 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 53]
+Fajardo, et al.              Standards Track                   [Page 52]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-         Example-AVP  ::= < AVP Header: 999999 >
-                          { Origin-Host }
-                        1*{ Session-Id }
-                         *[ AVP ]
-
-      An Example-AVP with Grouped Data follows.
-
-      The Origin-Host AVP is required (Section 6.3).  In this case:
-
-         Origin-Host = "example.com".
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-      One or more Session-Ids must follow.  Here there are two:
-
-         Session-Id =
-           "grump.example.com:33041;23432;893;0AF3B81"
-
-         Session-Id =
-           "grump.example.com:33054;23561;2358;0AF3B82"
-
       optional AVPs included are
 
          Recovery-Policy = <binary>
@@ -3007,25 +2934,42 @@ Internet-Draft           Diameter Base Protocol             January 2011
             41d018d56fe938f3cbf089aac12a912a2f0d1923a9390e5f789cb2e5067
             d3427475e49968f841
 
-   The data for the optional AVPs is represented in hex since the format
-   of these AVPs is neither known at the time of definition of the
-   Example-AVP group, nor (likely) at the time when the example instance
-   of this AVP is interpreted - except by Diameter implementations which
-   support the same set of AVPs.  The encoding example illustrates how
-   padding is used and how length fields are calculated.  Also note that
-   AVPs may be present in the Grouped AVP value which the receiver
-   cannot interpret (here, the Recover-Policy and Futuristic-Acct-Record
-   AVPs).  The length of the Example-AVP is the sum of all the length of
-   the member AVPs including their padding plus the Example-AVP header
+   The data for the optional AVPs is represented in hexadecimal form
+   since the format of these AVPs is not known at the time of definition
+   of the Example-AVP group nor (likely) at the time when the example
+   instance of this AVP is interpreted -- except by Diameter
+   implementations that support the same set of AVPs.  The encoding
+   example illustrates how padding is used and how length fields are
+   calculated.  Also, note that AVPs may be present in the Grouped AVP
+   value that the receiver cannot interpret (here, the Recover-Policy
+   and Futuristic-Acct-Record AVPs).  The length of the Example-AVP is
+   the sum of all the length of the member AVPs, including their
+   padding, plus the Example-AVP header size.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 54]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-   size.
+
+Fajardo, et al.              Standards Track                   [Page 53]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    This AVP would be encoded as follows:
@@ -3076,15 +3020,18 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 55]
+
+
+
+Fajardo, et al.              Standards Track                   [Page 54]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 4.5.  Diameter Base Protocol AVPs
 
    The following table describes the Diameter AVPs defined in the base
-   protocol, their AVP Code values, types, possible flag values.
+   protocol, their AVP Code values, types, and possible flag values.
 
    Due to space constraints, the short form DiamIdent is used to
    represent DiameterIdentity.
@@ -3132,9 +3079,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 56]
+Fajardo, et al.              Standards Track                   [Page 55]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
                                             +----------+
@@ -3154,7 +3101,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
      Record-Number                          |    |     |
    Accounting-      480  9.8.1   Enumerated | M  |  V  |
      Record-Type                            |    |     |
-   Accounting-       44  9.8.4   OctetString| M  |  V  |
+   Acct-             44  9.8.4   OctetString| M  |  V  |
     Session-Id                              |    |     |
    Accounting-      287  9.8.6   Unsigned64 | M  |  V  |
      Sub-Session-Id                         |    |     |
@@ -3188,9 +3135,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 57]
+Fajardo, et al.              Standards Track                   [Page 56]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
                                             +----------+
@@ -3244,9 +3191,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 58]
+Fajardo, et al.              Standards Track                   [Page 57]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 5.  Diameter Peers
@@ -3258,25 +3205,25 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    Connections between diameter peers are established using their valid
    DiameterIdentity.  A Diameter node initiating a connection to a peer
-   MUST know the peers DiameterIdentity.  Methods for discovering a
+   MUST know the peer's DiameterIdentity.  Methods for discovering a
    Diameter peer can be found in Section 5.2.
 
-   Although a Diameter node may have many possible peers that it is able
-   to communicate with, it may not be economical to have an established
-   connection to all of them.  At a minimum, a Diameter node SHOULD have
-   an established connection with two peers per realm, known as the
-   primary and secondary peers.  Of course, a node MAY have additional
-   connections, if it is deemed necessary.  Typically, all messages for
-   a realm are sent to the primary peer, but in the event that failover
-   procedures are invoked, any pending requests are sent to the
-   secondary peer.  However, implementations are free to load balance
-   requests between a set of peers.
-
-   Note that a given peer MAY act as a primary for a given realm, while
+   Although a Diameter node may have many possible peers with which it
+   is able to communicate, it may not be economical to have an
+   established connection to all of them.  At a minimum, a Diameter node
+   SHOULD have an established connection with two peers per realm, known
+   as the primary and secondary peers.  Of course, a node MAY have
+   additional connections, if it is deemed necessary.  Typically, all
+   messages for a realm are sent to the primary peer but, in the event
+   that failover procedures are invoked, any pending requests are sent
+   to the secondary peer.  However, implementations are free to load
+   balance requests between a set of peers.
+
+   Note that a given peer MAY act as a primary for a given realm while
    acting as a secondary for another realm.
 
    When a peer is deemed suspect, which could occur for various reasons,
-   including not receiving a DWA within an allotted timeframe, no new
+   including not receiving a DWA within an allotted time frame, no new
    requests should be forwarded to the peer, but failover procedures are
    invoked.  When an active peer is moved to this mode, additional
    connections SHOULD be established to ensure that the necessary number
@@ -3284,15 +3231,14 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    There are two ways that a peer is removed from the suspect peer list:
 
-
    1.  The peer is no longer reachable, causing the transport connection
-       to be shutdown.  The peer is moved to the closed state.
+       to be shut down.  The peer is moved to the closed state.
 
-   2.  Three watchdog messages are exchanged with accepted round trip
+   2.  Three watchdog messages are exchanged with accepted round-trip
        times, and the connection to the peer is considered stabilized.
 
    In the event the peer being removed is either the primary or
-   secondary, an alternate peer SHOULD replace the deleted peer, and
+   secondary, an alternate peer SHOULD replace the deleted peer and
    assume the role of either primary or secondary.
 
 
@@ -3300,99 +3246,106 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 59]
+
+Fajardo, et al.              Standards Track                   [Page 58]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 5.2.  Diameter Peer Discovery
 
-   Allowing for dynamic Diameter agent discovery will make it possible
-   for simpler and more robust deployment of Diameter services.  In
-   order to promote interoperable implementations of Diameter peer
-   discovery, the following mechanisms are described.  These are based
-   on existing IETF standards.  The first option (manual configuration)
-   MUST be supported by all Diameter nodes, while the latter option
-   (DNS) MAY be supported.
+   Allowing for dynamic Diameter agent discovery makes possible simpler
+   and more robust deployment of Diameter services.  In order to promote
+   interoperable implementations of Diameter peer discovery, the
+   following mechanisms (manual configuration and DNS) are described.
+   These are based on existing IETF standards.  Both mechanisms MUST be
+   supported by all Diameter implementations; either MAY be used.
 
    There are two cases where Diameter peer discovery may be performed.
    The first is when a Diameter client needs to discover a first-hop
    Diameter agent.  The second case is when a Diameter agent needs to
-   discover another agent - for further handling of a Diameter
-   operation.  In both cases, the following 'search order' is
-   recommended:
-
+   discover another agent for further handling of a Diameter operation.
+   In both cases, the following 'search order' is recommended:
 
-   1.  The Diameter implementation consults its list of static
+   1.  The Diameter implementation consults its list of statically
        (manually) configured Diameter agent locations.  These will be
        used if they exist and respond.
 
-
    2.  The Diameter implementation performs a NAPTR query for a server
-       in a particular realm.  The Diameter implementation has to know
-       in advance which realm to look for a Diameter agent.  This could
-       be deduced, for example, from the 'realm' in a NAI that a
-       Diameter implementation needed to perform a Diameter operation
-       on.
+       in a particular realm.  The Diameter implementation has to know,
+       in advance, in which realm to look for a Diameter agent.  This
+       could be deduced, for example, from the 'realm' in an NAI on
+       which a Diameter implementation needed to perform a Diameter
+       operation.
 
        The NAPTR usage in Diameter follows the S-NAPTR DDDS application
        [RFC3958] in which the SERVICE field includes tags for the
        desired application and supported application protocol.  The
        application service tag for a Diameter application is 'aaa' and
        the supported application protocol tags are 'diameter.tcp',
-       'diameter.sctp', 'diameter.dtls' or 'diameter.tls.tcp'.
+       'diameter.sctp', 'diameter.dtls', or 'diameter.tls.tcp'
+       [RFC6408].
 
        The client can follow the resolution process defined by the
-       S-NAPTR DDDS [RFC3958] application to find a matching SRV, A or
+       S-NAPTR DDDS [RFC3958] application to find a matching SRV, A, or
        AAAA record of a suitable peer.  The domain suffixes in the NAPTR
        replacement field SHOULD match the domain of the original query.
        An example can be found in Appendix B.
 
    3.  If no NAPTR records are found, the requester directly queries for
-       SRV records '_diameter._sctp'.realm, '_diameter._dtls'.realm,
-       '_diameter._tcp'.realm and '_diameter._tls'.realm depending on
-       the requesters network protocol capabilities.  If SRV records are
-       found then the requester can perform address record query (A RR's
+       one of the following SRV records: for Diameter over TCP, use
+       "_diameter._tcp.realm"; for Diameter over TLS, use
+       "_diameters._tcp.realm"; for Diameter over SCTP, use
+       "_diameter._sctp.realm"; for Diameter over DTLS, use
+       "_diameters._sctp.realm".  If SRV records are found, then the
+       requester can perform address record query (A RR's and/or AAAA
+
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 60]
+Fajardo, et al.              Standards Track                   [Page 59]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-       and/or AAAA RR's) for the target hostname specified in the SRV
-       records.  If no SRV records are found, the requester gives up.
+       RR's) for the target hostname specified in the SRV records
+       following the rules given in [RFC2782].  If no SRV records are
+       found, the requester gives up.
 
    If the server is using a site certificate, the domain name in the
    NAPTR query and the domain name in the replacement field MUST both be
    valid based on the site certificate handed out by the server in the
-   TLS/TCP and DTLS/SCTP or IKE exchange.  Similarly, the domain name in
-   the SRV query and the domain name in the target in the SRV record
-   MUST both be valid based on the same site certificate.  Otherwise, an
-   attacker could modify the DNS records to contain replacement values
-   in a different domain, and the client could not validate that this
-   was the desired behavior, or the result of an attack.
-
-   Also, the Diameter Peer MUST check to make sure that the discovered
+   TLS/TCP and DTLS/SCTP or Internet Key Exchange Protocol (IKE)
+   exchange.  Similarly, the domain name in the SRV query and the domain
+   name in the target in the SRV record MUST both be valid based on the
+   same site certificate.  Otherwise, an attacker could modify the DNS
+   records to contain replacement values in a different domain, and the
+   client could not validate whether this was the desired behavior or
+   the result of an attack.
+
+   Also, the Diameter peer MUST check to make sure that the discovered
    peers are authorized to act in its role.  Authentication via IKE or
    TLS/TCP and DTLS/SCTP, or validation of DNS RRs via DNSSEC is not
    sufficient to conclude this.  For example, a web server may have
    obtained a valid TLS/TCP and DTLS/SCTP certificate, and secured RRs
    may be included in the DNS, but this does not imply that it is
-   authorized to act as a Diameter Server.
-
-   Authorization can be achieved for example, by configuration of a
-   Diameter Server CA.  Alternatively this can be achieved by definition
-   of OIDs within TLS/TCP and DTLS/SCTP or IKE certificates so as to
-   signify Diameter Server authorization.
-
-   A dynamically discovered peer causes an entry in the Peer Table (see
+   authorized to act as a Diameter server.
+
+   Authorization can be achieved, for example, by the configuration of a
+   Diameter server Certification Authority (CA).  The server CA issues a
+   certificate to the Diameter server, which includes an Object
+   Identifier (OID) to indicate the subject is a Diameter server in the
+   Extended Key Usage extension [RFC5280].  This certificate is then
+   used during TLS/TCP, DTLS/SCTP, or IKE security negotiation.
+   However, note that, at the time of writing, no Diameter server
+   Certification Authorities exist.
+
+   A dynamically discovered peer causes an entry in the peer table (see
    Section 2.6) to be created.  Note that entries created via DNS MUST
-   expire (or be refreshed) within the DNS TTL.  If a peer is discovered
-   outside of the local realm, a routing table entry (see Section 2.7)
-   for the peer's realm is created.  The routing table entry's
-   expiration MUST match the peer's expiration value.
+   expire (or be refreshed) within the DNS Time to Live (TTL).  If a
+   peer is discovered outside of the local realm, a routing table entry
+   (see Section 2.7) for the peer's realm is created.  The routing table
+   entry's expiration MUST match the peer's expiration value.
 
 5.3.  Capabilities Exchange
 
@@ -3400,35 +3353,36 @@ Internet-Draft           Diameter Base Protocol             January 2011
    exchange the Capabilities Exchange messages, as specified in the peer
    state machine (see Section 5.6).  This message allows the discovery
    of a peer's identity and its capabilities (protocol version number,
-   supported Diameter applications, security mechanisms, etc.)
+   the identifiers of supported Diameter applications, security
+   mechanisms, etc.).
 
-   The receiver only issues commands to its peers that have advertised
-   support for the Diameter application that defines the command.  A
-   Diameter node MUST cache the supported applications in order to
-   ensure that unrecognized commands and/or AVPs are not unnecessarily
-   sent to a peer.
-
-   A receiver of a Capabilities-Exchange-Req (CER) message that does not
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 61]
+Fajardo, et al.              Standards Track                   [Page 60]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   have any applications in common with the sender MUST return a
+   The receiver only issues commands to its peers that have advertised
+   support for the Diameter application that defines the command.  A
+   Diameter node MUST cache the supported Application Ids in order to
+   ensure that unrecognized commands and/or AVPs are not unnecessarily
+   sent to a peer.
+
+   A receiver of a Capabilities-Exchange-Request (CER) message that does
+   not have any applications in common with the sender MUST return a
    Capabilities-Exchange-Answer (CEA) with the Result-Code AVP set to
-   DIAMETER_NO_COMMON_APPLICATION, and SHOULD disconnect the transport
+   DIAMETER_NO_COMMON_APPLICATION and SHOULD disconnect the transport
    layer connection.  Note that receiving a CER or CEA from a peer
-   advertising itself as a Relay (see Section 2.4) MUST be interpreted
+   advertising itself as a relay (see Section 2.4) MUST be interpreted
    as having common applications with the peer.
 
    The receiver of the Capabilities-Exchange-Request (CER) MUST
    determine common applications by computing the intersection of its
-   own set of supported Application Id against all of the application
-   identifier AVPs (Auth-Application-Id, Acct-Application-Id and Vendor-
-   Specific-Application-Id) present in the CER.  The value of the
+   own set of supported Application Ids against all of the
+   Application-Id AVPs (Auth-Application-Id, Acct-Application-Id, and
+   Vendor-Specific-Application-Id) present in the CER.  The value of the
    Vendor-Id AVP in the Vendor-Specific-Application-Id MUST NOT be used
    during computation.  The sender of the Capabilities-Exchange-Answer
    (CEA) SHOULD include all of its supported applications as a hint to
@@ -3438,12 +3392,13 @@ Internet-Draft           Diameter Base Protocol             January 2011
    and DTLS/SCTP connection prior to the CER/CEA exchange.  This
    protects the capabilities information of both peers.  To support
    older Diameter implementations that do not fully conform to this
-   document, the transport security MAY still be negotiated via Inband-
-   Security AVP.  In this case, the receiver of a Capabilities-Exchange-
-   Req (CER) message that does not have any security mechanisms in
-   common with the sender MUST return a Capabilities-Exchange-Answer
-   (CEA) with the Result-Code AVP set to DIAMETER_NO_COMMON_SECURITY,
-   and SHOULD disconnect the transport layer connection.
+   document, the transport security MAY still be negotiated via an
+   Inband-Security AVP.  In this case, the receiver of a Capabilities-
+   Exchange-Request (CER) message that does not have any security
+   mechanisms in common with the sender MUST return a Capabilities-
+   Exchange-Answer (CEA) with the Result-Code AVP set to
+   DIAMETER_NO_COMMON_SECURITY and SHOULD disconnect the transport layer
+   connection.
 
    CERs received from unknown peers MAY be silently discarded, or a CEA
    MAY be issued with the Result-Code AVP set to DIAMETER_UNKNOWN_PEER.
@@ -3455,34 +3410,34 @@ Internet-Draft           Diameter Base Protocol             January 2011
    failure, all the pending transactions destined to the unknown peer
    can be discarded.
 
-   The CER and CEA messages MUST NOT be proxied, redirected or relayed.
+   The CER and CEA messages MUST NOT be proxied, redirected, or relayed.
 
-   Since the CER/CEA messages cannot be proxied, it is still possible
-   that an upstream agent receives a message for which it has no
-   available peers to handle the application that corresponds to the
-   Command-Code.  In such instances, the 'E' bit is set in the answer
-   message (see Section 7.) with the Result-Code AVP set to
-   DIAMETER_UNABLE_TO_DELIVER to inform the downstream to take action
-   (e.g., re-routing request to an alternate peer).
 
 
 
-
-Fajardo, et al.           Expires July 24, 2011                [Page 62]
+Fajardo, et al.              Standards Track                   [Page 61]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+   Since the CER/CEA messages cannot be proxied, it is still possible
+   that an upstream agent will receive a message for which it has no
+   available peers to handle the application that corresponds to the
+   Command Code.  In such instances, the 'E' bit is set in the answer
+   message (Section 7) with the Result-Code AVP set to
+   DIAMETER_UNABLE_TO_DELIVER to inform the downstream agent to take
+   action (e.g., re-routing request to an alternate peer).
+
    With the exception of the Capabilities-Exchange-Request message, a
    message of type Request that includes the Auth-Application-Id or
    Acct-Application-Id AVPs, or a message with an application-specific
-   command code, MAY only be forwarded to a host that has explicitly
+   Command Code MAY only be forwarded to a host that has explicitly
    advertised support for the application (or has advertised the Relay
    Application Id).
 
 5.3.1.  Capabilities-Exchange-Request
 
-   The Capabilities-Exchange-Request (CER), indicated by the Command-
+   The Capabilities-Exchange-Request (CER), indicated by the Command
    Code set to 257 and the Command Flags' 'R' bit set, is sent to
    exchange local capabilities.  Upon detection of a transport failure,
    this message MUST NOT be sent to an alternate peer.
@@ -3490,7 +3445,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    When Diameter is run over SCTP [RFC4960] or DTLS/SCTP [RFC6083],
    which allow for connections to span multiple interfaces and multiple
    IP addresses, the Capabilities-Exchange-Request message MUST contain
-   one Host-IP- Address AVP for each potential IP address that MAY be
+   one Host-IP-Address AVP for each potential IP address that MAY be
    locally used when transmitting Diameter messages.
 
       Message Format
@@ -3510,9 +3465,20 @@ Internet-Draft           Diameter Base Protocol             January 2011
                    [ Firmware-Revision ]
                  * [ AVP ]
 
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 62]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 5.3.2.  Capabilities-Exchange-Answer
 
-   The Capabilities-Exchange-Answer (CEA), indicated by the Command-Code
+   The Capabilities-Exchange-Answer (CEA), indicated by the Command Code
    set to 257 and the Command Flags' 'R' bit cleared, is sent in
    response to a CER message.
 
@@ -3522,13 +3488,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
    one Host-IP-Address AVP for each potential IP address that MAY be
    locally used when transmitting Diameter messages.
 
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 63]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    Message Format
 
          <CEA> ::= < Diameter Header: 257 >
@@ -3552,22 +3511,34 @@ Internet-Draft           Diameter Base Protocol             January 2011
 5.3.3.  Vendor-Id AVP
 
    The Vendor-Id AVP (AVP Code 266) is of type Unsigned32 and contains
-   the IANA "SMI Network Management Private Enterprise Codes" [RFC3232]
-   value assigned to the vendor of the Diameter device.  It is
+   the IANA "SMI Network Management Private Enterprise Codes"
+   [ENTERPRISE] value assigned to the Diameter Software vendor.  It is
    envisioned that the combination of the Vendor-Id, Product-Name
-   (Section 5.3.7) and the Firmware-Revision (Section 5.3.4) AVPs may
+   (Section 5.3.7), and Firmware-Revision (Section 5.3.4) AVPs may
    provide useful debugging information.
 
-   A Vendor-Id value of zero in the CER or CEA messages is reserved and
+   A Vendor-Id value of zero in the CER or CEA message is reserved and
    indicates that this field is ignored.
 
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 63]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 5.3.4.  Firmware-Revision AVP
 
    The Firmware-Revision AVP (AVP Code 267) is of type Unsigned32 and is
    used to inform a Diameter peer of the firmware revision of the
    issuing device.
 
-   For devices that do not have a firmware revision (general purpose
+   For devices that do not have a firmware revision (general-purpose
    computers running Diameter software modules, for instance), the
    revision of the Diameter software module may be reported instead.
 
@@ -3577,77 +3548,70 @@ Internet-Draft           Diameter Base Protocol             January 2011
    to inform a Diameter peer of the sender's IP address.  All source
    addresses that a Diameter node expects to use with SCTP [RFC4960] or
    DTLS/SCTP [RFC6083] MUST be advertised in the CER and CEA messages by
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 64]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    including a Host-IP-Address AVP for each address.
 
 5.3.6.  Supported-Vendor-Id AVP
 
    The Supported-Vendor-Id AVP (AVP Code 265) is of type Unsigned32 and
    contains the IANA "SMI Network Management Private Enterprise Codes"
-   [RFC3232] value assigned to a vendor other than the device vendor but
-   including the application vendor.  This is used in the CER and CEA
-   messages in order to inform the peer that the sender supports (a
-   subset of) the vendor-specific AVPs defined by the vendor identified
+   [ENTERPRISE] value assigned to a vendor other than the device vendor
+   but including the application vendor.  This is used in the CER and
+   CEA messages in order to inform the peer that the sender supports (a
+   subset of) the Vendor-Specific AVPs defined by the vendor identified
    in this AVP.  The value of this AVP MUST NOT be set to zero.
    Multiple instances of this AVP containing the same value SHOULD NOT
    be sent.
 
 5.3.7.  Product-Name AVP
 
-   The Product-Name AVP (AVP Code 269) is of type UTF8String, and
-   contains the vendor assigned name for the product.  The Product-Name
+   The Product-Name AVP (AVP Code 269) is of type UTF8String and
+   contains the vendor-assigned name for the product.  The Product-Name
    AVP SHOULD remain constant across firmware revisions for the same
    product.
 
-5.4.  Disconnecting Peer connections
+5.4.  Disconnecting Peer Connections
 
    When a Diameter node disconnects one of its transport connections,
-   its peer cannot know the reason for the disconnect, and will most
-   likely assume that a connectivity problem occurred, or that the peer
+   its peer cannot know the reason for the disconnect and will most
+   likely assume that a connectivity problem occurred or that the peer
    has rebooted.  In these cases, the peer may periodically attempt to
    reconnect, as stated in Section 2.1.  In the event that the
-   disconnect was a result of either a shortage of internal resources,
-   or simply that the node in question has no intentions of forwarding
-   any Diameter messages to the peer in the foreseeable future, a
-   periodic connection request would not be welcomed.  The
-   Disconnection-Reason AVP contains the reason the Diameter node issued
-   the Disconnect-Peer-Request message.
+   disconnect was a result of either a shortage of internal resources or
+   simply that the node in question has no intentions of forwarding any
+   Diameter messages to the peer in the foreseeable future, a periodic
 
-   The Disconnect-Peer-Request message is used by a Diameter node to
-   inform its peer of its intent to disconnect the transport layer, and
-   that the peer shouldn't reconnect unless it has a valid reason to do
-   so (e.g., message to be forwarded).  Upon receipt of the message, the
-   Disconnect-Peer-Answer is returned, which SHOULD contain an error if
-   messages have recently been forwarded, and are likely in flight,
-   which would otherwise cause a race condition.
 
-   The receiver of the Disconnect-Peer-Answer initiates the transport
-   disconnect.  The sender of the Disconnect-Peer-Answer should be able
-   to detect the transport closure and cleanup the connection.
 
 
+Fajardo, et al.              Standards Track                   [Page 64]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+   connection request would not be welcomed.  The Disconnection-Reason
+   AVP contains the reason the Diameter node issued the Disconnect-Peer-
+   Request message.
 
-Fajardo, et al.           Expires July 24, 2011                [Page 65]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   The Disconnect-Peer-Request message is used by a Diameter node to
+   inform its peer of its intent to disconnect the transport layer and
+   that the peer shouldn't reconnect unless it has a valid reason to do
+   so (e.g., message to be forwarded).  Upon receipt of the message, the
+   Disconnect-Peer-Answer message is returned, which SHOULD contain an
+   error if messages have recently been forwarded, and are likely in
+   flight, which would otherwise cause a race condition.
 
+   The receiver of the Disconnect-Peer-Answer message initiates the
+   transport disconnect.  The sender of the Disconnect-Peer-Answer
+   message should be able to detect the transport closure and clean up
+   the connection.
 
 5.4.1.  Disconnect-Peer-Request
 
-   The Disconnect-Peer-Request (DPR), indicated by the Command-Code set
+   The Disconnect-Peer-Request (DPR), indicated by the Command Code set
    to 282 and the Command Flags' 'R' bit set, is sent to a peer to
-   inform its intentions to shutdown the transport connection.  Upon
-   detection of a transport failure, this message MUST NOT be sent to an
-   alternate peer.
+   inform it of its intentions to shut down the transport connection.
+   Upon detection of a transport failure, this message MUST NOT be sent
+   to an alternate peer.
 
       Message Format
 
@@ -3659,28 +3623,14 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 5.4.2.   Disconnect-Peer-Answer
 
-   The Disconnect-Peer-Answer (DPA), indicated by the Command-Code set
+   The Disconnect-Peer-Answer (DPA), indicated by the Command Code set
    to 282 and the Command Flags' 'R' bit cleared, is sent as a response
    to the Disconnect-Peer-Request message.  Upon receipt of this
-   message, the transport connection is shutdown.
+   message, the transport connection is shut down.
 
-      Message Format
 
-         <DPA>  ::= < Diameter Header: 282 >
-                    { Result-Code }
-                    { Origin-Host }
-                    { Origin-Realm }
-                    [ Error-Message ]
-                    [ Failed-AVP ]
-                  * [ AVP ]
 
-5.4.3.   Disconnect-Cause AVP
 
-   The Disconnect-Cause AVP (AVP Code 273) is of type Enumerated.  A
-   Diameter node MUST include this AVP in the Disconnect-Peer-Request
-   message to inform the peer of the reason for its intention to
-   shutdown the transport connection.  The following values are
-   supported:
 
 
 
@@ -3689,29 +3639,44 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
+Fajardo, et al.              Standards Track                   [Page 65]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+      Message Format
+
+         <DPA>  ::= < Diameter Header: 282 >
+                    { Result-Code }
+                    { Origin-Host }
+                    { Origin-Realm }
+                    [ Error-Message ]
+                    [ Failed-AVP ]
+                  * [ AVP ]
 
-Fajardo, et al.           Expires July 24, 2011                [Page 66]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
+5.4.3.   Disconnect-Cause AVP
+
+   The Disconnect-Cause AVP (AVP Code 273) is of type Enumerated.  A
+   Diameter node MUST include this AVP in the Disconnect-Peer-Request
+   message to inform the peer of the reason for its intention to shut
+   down the transport connection.  The following values are supported:
 
-    REBOOTING                         0
-       A scheduled reboot is imminent. Receiver of DPR with above result
-       code MAY attempt reconnection.
+      REBOOTING                         0
+         A scheduled reboot is imminent.  A receiver of a DPR with
+         above result code MAY attempt reconnection.
 
-    BUSY                              1
-       The peer's internal resources are constrained, and it has
-       determined that the transport connection needs to be closed.
-       Receiver of DPR with above result code SHOULD NOT attempt
-       reconnection.
+      BUSY                              1
+         The peer's internal resources are constrained, and it has
+         determined that the transport connection needs to be closed.
+         A receiver of a DPR with above result code SHOULD NOT attempt
+         reconnection.
 
-    DO_NOT_WANT_TO_TALK_TO_YOU        2
-       The peer has determined that it does not see a need for the
-       transport connection to exist, since it does not expect any
-       messages to be exchanged in the near future. Receiver of DPR
-       with above result code SHOULD NOT attempt reconnection.
+      DO_NOT_WANT_TO_TALK_TO_YOU        2
+         The peer has determined that it does not see a need for the
+         transport connection to exist, since it does not expect any
+         messages to be exchanged in the near future.  A receiver of a
+         DPR with above result code SHOULD NOT attempt reconnection.
 
 5.5.  Transport Failure Detection
 
@@ -3723,9 +3688,21 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Watchdog-Answer messages, defined in this section, are used to pro-
    actively detect transport failures.
 
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 66]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 5.5.1.  Device-Watchdog-Request
 
-   The Device-Watchdog-Request (DWR), indicated by the Command-Code set
+   The Device-Watchdog-Request (DWR), indicated by the Command Code set
    to 280 and the Command Flags' 'R' bit set, is sent to a peer when no
    traffic has been exchanged between two peers (see Section 5.5.3).
    Upon detection of a transport failure, this message MUST NOT be sent
@@ -3741,18 +3718,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 5.5.2.  Device-Watchdog-Answer
 
-   The Device-Watchdog-Answer (DWA), indicated by the Command-Code set
+   The Device-Watchdog-Answer (DWA), indicated by the Command Code set
    to 280 and the Command Flags' 'R' bit cleared, is sent as a response
    to the Device-Watchdog-Request message.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 67]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       Message Format
 
          <DWA>  ::= < Diameter Header: 280 >
@@ -3767,7 +3736,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
 5.5.3.   Transport Failure Algorithm
 
    The transport failure algorithm is defined in [RFC3539].  All
-   Diameter implementations MUST support the algorithm defined in the
+   Diameter implementations MUST support the algorithm defined in that
    specification in order to be compliant to the Diameter base protocol.
 
 5.5.4.  Failover and Failback Procedures
@@ -3775,7 +3744,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
    In the event that a transport failure is detected with a peer, it is
    necessary for all pending request messages to be forwarded to an
    alternate agent, if possible.  This is commonly referred to as
-   failover.
+   "failover".
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 67]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    In order for a Diameter node to perform failover procedures, it is
    necessary for the node to maintain a pending message queue for a
@@ -3783,16 +3762,16 @@ Internet-Draft           Diameter Base Protocol             January 2011
    request is removed from the queue.  The Hop-by-Hop Identifier field
    is used to match the answer with the queued request.
 
-   When a transport failure is detected, if possible all messages in the
-   queue are sent to an alternate agent with the T flag set.  On booting
-   a Diameter client or agent, the T flag is also set on any records
-   still remaining to be transmitted in non-volatile storage.  An
-   example of a case where it is not possible to forward the message to
-   an alternate server is when the message has a fixed destination, and
-   the unavailable peer is the message's final destination (see
-   Destination-Host AVP).  Such an error requires that the agent return
-   an answer message with the 'E' bit set and the Result-Code AVP set to
-   DIAMETER_UNABLE_TO_DELIVER.
+   When a transport failure is detected, if possible, all messages in
+   the queue are sent to an alternate agent with the T flag set.  On
+   booting a Diameter client or agent, the T flag is also set on any
+   remaining records in non-volatile storage that are still waiting to
+   be transmitted.  An example of a case where it is not possible to
+   forward the message to an alternate server is when the message has a
+   fixed destination, and the unavailable peer is the message's final
+   destination (see Destination-Host AVP).  Such an error requires that
+   the agent return an answer message with the 'E' bit set and the
+   Result-Code AVP set to DIAMETER_UNABLE_TO_DELIVER.
 
    It is important to note that multiple identical requests or answers
    MAY be received as a result of a failover.  The End-to-End Identifier
@@ -3801,17 +3780,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    As described in Section 2.1, a connection request should be
    periodically attempted with the failed peer in order to re-establish
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 68]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    the transport connection.  Once a connection has been successfully
    established, messages can once again be forwarded to the peer.  This
-   is commonly referred to as failback.
+   is commonly referred to as "failback".
 
 5.6.  Peer State Machine
 
@@ -3824,16 +3795,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    This state machine is closely coupled with the state machine
    described in [RFC3539], which is used to open, close, failover,
-   probe, and reopen transport connections.  Note in particular that
+   probe, and reopen transport connections.  In particular, note that
    [RFC3539] requires the use of watchdog messages to probe connections.
    For Diameter, DWR and DWA messages are to be used.
 
-   I- is used to represent the initiator (connecting) connection, while
-   the R- is used to represent the responder (listening) connection.
-   The lack of a prefix indicates that the event or action is the same
-   regardless of the connection on which the event occurred.
+   The I- prefix is used to represent the initiator (connecting)
+   connection, while the R- prefix is used to represent the responder
+   (listening) connection.  The lack of a prefix indicates that the
+   event or action is the same regardless of the connection on which the
+   event occurred.
+
+
+
+Fajardo, et al.              Standards Track                   [Page 68]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
-   The stable states that a state machine may be in are Closed, I-Open
+   The stable states that a state machine may be in are Closed, I-Open,
    and R-Open; all other states are intermediate.  Note that I-Open and
    R-Open are equivalent except for whether the initiator or responder
    transport connection is used for communication.
@@ -3848,23 +3827,15 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the results of an election on one peer are guaranteed to be the
    inverse of the results on the other.
 
-   For TLS/TCP and DTLS/SCTP usage, TLS/TCP and DTLS/SCTP handshake
+   For TLS/TCP and DTLS/SCTP usage, a TLS/TCP and DTLS/SCTP handshake
    SHOULD begin when both ends are in the closed state prior to any
    Diameter message exchanges.  The TLS/TCP and DTLS/SCTP connection
    SHOULD be established before sending any CER or CEA message to secure
    and protect the capabilities information of both peers.  The TLS/TCP
    and DTLS/SCTP connection SHOULD be disconnected when the state
    machine moves to the closed state.  When connecting to responders
-   that do not conform to this document (i.e. older Diameter
+   that do not conform to this document (i.e., older Diameter
    implementations that are not prepared to received TLS/TCP and DTLS/
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 69]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    SCTP connections in the closed state), the initial TLS/TCP and DTLS/
    SCTP connection attempt will fail.  The initiator MAY then attempt to
    connect via TCP or SCTP and initiate the TLS/TCP and DTLS/SCTP
@@ -3878,6 +3849,25 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Any implementation that produces equivalent results is considered
    compliant.
 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 69]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
       state            event              action         next state
       -----------------------------------------------------------------
       Closed           Start            I-Snd-Conn-Req   Wait-Conn-Ack
@@ -3914,13 +3904,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
                        R-Conn-CER       R-Reject         Wait-Returns
                        Timeout          Error            Closed
 
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 70]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       R-Open           Send-Message     R-Snd-Message    R-Open
                        R-Rcv-Message    Process          R-Open
                        R-Rcv-DWR        Process-DWR,     R-Open
@@ -3928,10 +3911,19 @@ Internet-Draft           Diameter Base Protocol             January 2011
                        R-Rcv-DWA        Process-DWA      R-Open
                        R-Conn-CER       R-Reject         R-Open
                        Stop             R-Snd-DPR        Closing
-                       R-Rcv-DPR        R-Snd-DPA,       Closed
-                                        R-Disc
+                       R-Rcv-DPR        R-Snd-DPA        Closing
                        R-Peer-Disc      R-Disc           Closed
 
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 70]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
       I-Open           Send-Message     I-Snd-Message    I-Open
                        I-Rcv-Message    Process          I-Open
                        I-Rcv-DWR        Process-DWR,     I-Open
@@ -3939,8 +3931,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
                        I-Rcv-DWA        Process-DWA      I-Open
                        R-Conn-CER       R-Reject         I-Open
                        Stop             I-Snd-DPR        Closing
-                       I-Rcv-DPR        I-Snd-DPA,       Closed
-                                        I-Disc
+                       I-Rcv-DPR        I-Snd-DPA        Closing
                        I-Peer-Disc      I-Disc           Closed
 
       Closing          I-Rcv-DPA        I-Disc           Closed
@@ -3949,88 +3940,44 @@ Internet-Draft           Diameter Base Protocol             January 2011
                        I-Peer-Disc      I-Disc           Closed
                        R-Peer-Disc      R-Disc           Closed
 
-5.6.1.  Incoming connections
+5.6.1.  Incoming Connections
 
    When a connection request is received from a Diameter peer, it is
    not, in the general case, possible to know the identity of that peer
    until a CER is received from it.  This is because host and port
-   determine the identity of a Diameter peer; and the source port of an
-   incoming connection is arbitrary.  Upon receipt of CER, the identity
-   of the connecting peer can be uniquely determined from Origin-Host.
+   determine the identity of a Diameter peer; the source port of an
+   incoming connection is arbitrary.  Upon receipt of a CER, the
+   identity of the connecting peer can be uniquely determined from the
+   Origin-Host.
 
    For this reason, a Diameter peer must employ logic separate from the
    state machine to receive connection requests, accept them, and await
-   CER.  Once CER arrives on a new connection, the Origin-Host that
-   identifies the peer is used to locate the state machine associated
-   with that peer, and the new connection and CER are passed to the
-   state machine as an R-Conn-CER event.
+   the CER.  Once the CER arrives on a new connection, the Origin-Host
+   that identifies the peer is used to locate the state machine
+   associated with that peer, and the new connection and CER are passed
+   to the state machine as an R-Conn-CER event.
 
    The logic that handles incoming connections SHOULD close and discard
-   the connection if any message other than CER arrives, or if an
+   the connection if any message other than a CER arrives or if an
    implementation-defined timeout occurs prior to receipt of CER.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 71]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    Because handling of incoming connections up to and including receipt
-   of CER requires logic, separate from that of any individual state
+   of a CER requires logic, separate from that of any individual state
    machine associated with a particular peer, it is described separately
    in this section rather than in the state machine above.
 
 5.6.2.  Events
 
    Transitions and actions in the automaton are caused by events.  In
-   this section, we will ignore the -I and -R prefix, since the actual
-   event would be identical, but would occur on one of two possible
+   this section, we will ignore the I- and R- prefixes, since the actual
+   event would be identical, but it would occur on one of two possible
    connections.
 
 
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 72]
+Fajardo, et al.              Standards Track                   [Page 71]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Start          The Diameter application has signaled that a
@@ -4053,7 +4000,8 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    Rcv-CEA        A CEA message from the peer was received.
 
-   Rcv-Non-CEA    A message other than CEA from the peer was received.
+   Rcv-Non-CEA    A message, other than a CEA, from the peer was
+                  received.
 
    Peer-Disc      A disconnection indication from the peer was received.
 
@@ -4066,7 +4014,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    Send-Message   A message is to be sent.
 
-   Rcv-Message    A message other than CER, CEA, DPR, DPA, DWR or DWA
+   Rcv-Message    A message other than CER, CEA, DPR, DPA, DWR, or DWA
                   was received.
 
    Stop           The Diameter application has signaled that a
@@ -4077,16 +4025,15 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    Actions in the automaton are caused by events and typically indicate
    the transmission of packets and/or an action to be taken on the
-   connection.  In this section we will ignore the I- and R-prefix,
-   since the actual action would be identical, but would occur on one of
-   two possible connections.
-
+   connection.  In this section, we will ignore the I- and R- prefixes,
+   since the actual action would be identical, but it would occur on one
+   of two possible connections.
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 73]
+Fajardo, et al.              Standards Track                   [Page 72]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    Snd-Conn-Req   A transport connection is initiated with the peer.
@@ -4098,11 +4045,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
                   is disconnected.
 
    Process-CER    The CER associated with the R-Conn-CER is processed.
+
    Snd-CER        A CER message is sent to the peer.
 
    Snd-CEA        A CEA message is sent to the peer.
 
-   Cleanup        If necessary, the connection is shutdown, and any
+   Cleanup        If necessary, the connection is shut down, and any
                   local resources are freed.
 
    Error          The transport layer connection is disconnected,
@@ -4139,10 +4087,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-
-Fajardo, et al.           Expires July 24, 2011                [Page 74]
+Fajardo, et al.              Standards Track                   [Page 73]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 5.6.4.  The Election Process
@@ -4150,134 +4097,97 @@ Internet-Draft           Diameter Base Protocol             January 2011
    The election is performed on the responder.  The responder compares
    the Origin-Host received in the CER with its own Origin-Host as two
    streams of octets.  If the local Origin-Host lexicographically
-   succeeds the received Origin-Host a Win-Election event is issued
-   locally.  Diameter identities are in ASCII form therefore the lexical
-   comparison is consistent with DNS case insensitivity where octets
-   that fall in the ASCII range 'a' through 'z' MUST compare equally to
-   their upper-case counterparts between 'A' and 'Z'.  See Appendix D
-   for interactions between the Diameter protocol and Internationalized
-   Domain Name (IDNs).
+   succeeds the received Origin-Host, a Win-Election event is issued
+   locally.  Diameter identities are in ASCII form; therefore, the
+   lexical comparison is consistent with DNS case insensitivity, where
+   octets that fall in the ASCII range 'a' through 'z' MUST compare
+   equally to their uppercase counterparts between 'A' and 'Z'.  See
+   Appendix D for interactions between the Diameter protocol and
+   Internationalized Domain Name (IDNs).
 
    The winner of the election MUST close the connection it initiated.
    Historically, maintaining the responder side of a connection was more
    efficient than maintaining the initiator side.  However, current
    practices makes this distinction irrelevant.
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 75]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-6.  Diameter message processing
+6.  Diameter Message Processing
 
    This section describes how Diameter requests and answers are created
    and processed.
 
 6.1.  Diameter Request Routing Overview
 
-   A request is sent towards its final destination using a combination
-   of the Destination-Realm and Destination-Host AVPs, in one of these
-   three combinations:
+   A request is sent towards its final destination using one of the
+   following three combinations of the Destination-Realm and
+   Destination-Host AVPs:
 
-   o  a request that is not able to be proxied (such as CER) MUST NOT
+   o  A request that is not able to be proxied (such as a CER) MUST NOT
       contain either Destination-Realm or Destination-Host AVPs.
 
-   o  a request that needs to be sent to a home server serving a
+   o  A request that needs to be sent to a home server serving a
       specific realm, but not to a specific server (such as the first
-      request of a series of round-trips), MUST contain a Destination-
-      Realm AVP, but MUST NOT contain a Destination-Host AVP.  For
+      request of a series of round trips), MUST contain a Destination-
+      Realm AVP but MUST NOT contain a Destination-Host AVP.  For
       Diameter clients, the value of the Destination-Realm AVP MAY be
       extracted from the User-Name AVP, or other methods.
 
-   o  otherwise, a request that needs to be sent to a specific home
-      server among those serving a given realm, MUST contain both the
+   o  Otherwise, a request that needs to be sent to a specific home
+      server among those serving a given realm MUST contain both the
       Destination-Realm and Destination-Host AVPs.
 
    The Destination-Host AVP is used as described above when the
    destination of the request is fixed, which includes:
 
-   o  Authentication requests that span multiple round trips
+   o  Authentication requests that span multiple round trips.
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 74]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    o  A Diameter message that uses a security mechanism that makes use
       of a pre-established session key shared between the source and the
       final destination of the message.
 
-   o  Server initiated messages that MUST be received by a specific
+   o  Server-initiated messages that MUST be received by a specific
       Diameter client (e.g., access device), such as the Abort-Session-
       Request message, which is used to request that a particular user's
       session be terminated.
 
-   Note that an agent can forward a request to a host described in the
-   Destination-Host AVP only if the host in question is included in its
-   peer table (see Section 2.7).  Otherwise, the request is routed based
-   on the Destination-Realm only (see Sections 6.1.6).
+   Note that an agent can only forward a request to a host described in
+   the Destination-Host AVP if the host in question is included in its
+   peer table (see Section 2.6).  Otherwise, the request is routed based
+   on the Destination-Realm only (see Section 6.1.6).
 
    When a message is received, the message is processed in the following
    order:
 
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 76]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    o  If the message is destined for the local host, the procedures
       listed in Section 6.1.4 are followed.
 
    o  If the message is intended for a Diameter peer with whom the local
       host is able to directly communicate, the procedures listed in
-      Section 6.1.5 are followed.  This is known as Request Forwarding.
+      Section 6.1.5 are followed.  This is known as "Request
+      Forwarding".
 
-   o  The procedures listed in Section 6.1.6 are followed, which is
-      known as Request Routing.
+   o  The procedure listed in Section 6.1.6 is followed, which is known
+      as "Request Routing".
 
-   o  If none of the above is successful, an answer is returned with the
-      Result-Code set to DIAMETER_UNABLE_TO_DELIVER, with the E-bit set.
+   o  If none of the above are successful, an answer is returned with
+      the Result-Code set to DIAMETER_UNABLE_TO_DELIVER, with the 'E'
+      bit set.
 
    For routing of Diameter messages to work within an administrative
    domain, all Diameter nodes within the realm MUST be peers.
 
-   Note the processing rules contained in this section are intended to
-   be used as general guidelines to Diameter developers.  Certain
-   implementations MAY use different methods than the ones described
-   here, and still comply with the protocol specification.  See Section
-   7 for more detail on error handling.
+   The overview contained in this section (6.1) is intended to provide
+   general guidelines to Diameter developers.  Implementations are free
+   to use different methods than the ones described here as long as they
+   conform to the requirements specified in Sections 6.1.1 through
+   6.1.9.  See Section 7 for more details on error handling.
 
 6.1.1.  Originating a Request
 
@@ -4285,33 +4195,35 @@ Internet-Draft           Diameter Base Protocol             January 2011
    described in the application definition for that specific request,
    the following procedures MUST be followed:
 
-   o  the Command-Code is set to the appropriate value
 
-   o  the 'R' bit is set
 
-   o  the End-to-End Identifier is set to a locally unique value
 
-   o  the Origin-Host and Origin-Realm AVPs MUST be set to the
-      appropriate values, used to identify the source of the message
 
-   o  the Destination-Host and Destination-Realm AVPs MUST be set to the
-      appropriate values as described in Section 6.1.
+Fajardo, et al.              Standards Track                   [Page 75]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-6.1.2.  Sending a Request
 
-   When sending a request, originated either locally, or as the result
-   of a forwarding or routing operation, the following procedures SHOULD
-   be followed:
+   o  the Command Code is set to the appropriate value;
 
-   o  The Hop-by-Hop Identifier SHOULD be set to a locally unique value.
+   o  the 'R' bit is set;
 
+   o  the End-to-End Identifier is set to a locally unique value;
 
+   o  the Origin-Host and Origin-Realm AVPs MUST be set to the
+      appropriate values, used to identify the source of the message;
+      and
 
+   o  the Destination-Host and Destination-Realm AVPs MUST be set to the
+      appropriate values, as described in Section 6.1.
 
-Fajardo, et al.           Expires July 24, 2011                [Page 77]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+6.1.2.  Sending a Request
 
+   When sending a request, originated either locally or as the result of
+   a forwarding or routing operation, the following procedures SHOULD be
+   followed:
+
+   o  The Hop-by-Hop Identifier SHOULD be set to a locally unique value.
 
    o  The message SHOULD be saved in the list of pending requests.
 
@@ -4328,25 +4240,34 @@ Internet-Draft           Diameter Base Protocol             January 2011
 6.1.4.  Processing Local Requests
 
    A request is known to be for local consumption when one of the
-   following conditions occur:
+   following conditions occurs:
 
-   o  The Destination-Host AVP contains the local host's identity,
+   o  The Destination-Host AVP contains the local host's identity;
 
    o  The Destination-Host AVP is not present, the Destination-Realm AVP
       contains a realm the server is configured to process locally, and
-      the Diameter application is locally supported, or
+      the Diameter application is locally supported; or
 
    o  Both the Destination-Host and the Destination-Realm are not
       present.
 
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 76]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    When a request is locally processed, the rules in Section 6.2 should
    be used to generate the corresponding answer.
 
 6.1.5.  Request Forwarding
 
-   Request forwarding is done using the Diameter Peer Table.  The
-   Diameter peer table contains all of the peers that the local node is
-   able to directly communicate with.
+   Request forwarding is done using the Diameter peer table.  The
+   Diameter peer table contains all of the peers with which the local
+   node is able to directly communicate.
 
    When a request is received, and the host encoded in the Destination-
    Host AVP is one that is present in the peer table, the message SHOULD
@@ -4354,29 +4275,21 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 6.1.6.  Request Routing
 
-   Diameter request message routing is done via realms and application
-   identifiers.  A Diameter message that may be forwarded by Diameter
-   agents (proxies, redirect or relay agents) MUST include the target
+   Diameter request message routing is done via realms and Application
+   Ids. A Diameter message that may be forwarded by Diameter agents
+   (proxies, redirect agents, or relay agents) MUST include the target
    realm in the Destination-Realm AVP.  Request routing SHOULD rely on
    the Destination-Realm AVP and the Application Id present in the
    request message header to aid in the routing decision.  The realm MAY
    be retrieved from the User-Name AVP, which is in the form of a
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 78]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    Network Access Identifier (NAI).  The realm portion of the NAI is
    inserted in the Destination-Realm AVP.
 
    Diameter agents MAY have a list of locally supported realms and
-   applications, and MAY have a list of externally supported realms and
-   applications.  When a request is received that includes a realm
+   applications, and they MAY have a list of externally supported realms
+   and applications.  When a request is received that includes a realm
    and/or application that is not locally supported, the message is
-   routed to the peer configured in the Routing Table (see Section 2.7).
+   routed to the peer configured in the routing table (see Section 2.7).
 
    Realm names and Application Ids are the minimum supported routing
    criteria, additional information may be needed to support redirect
@@ -4385,13 +4298,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
 6.1.7.  Predictive Loop Avoidance
 
    Before forwarding or routing a request, Diameter agents, in addition
-   to processing done in Section 6.1.3, SHOULD check for the presence of
-   candidate route's peer identity in any of the Route-Record AVPs.  In
-   an event of the agent detecting the presence of a candidate route's
-   peer identity in a Route-Record AVP, the agent MUST ignore such route
-   for the Diameter request message and attempt alternate routes if any.
-   In case all the candidate routes are eliminated by the above
-   criteria, the agent SHOULD return DIAMETER_UNABLE_TO_DELIVER message.
+   to performing the processing described in Section 6.1.3, SHOULD check
+   for the presence of a candidate route's peer identity in any of the
+   Route-Record AVPs.  In the event of the agent detecting the presence
+   of a candidate route's peer identity in a Route-Record AVP, the agent
+   MUST ignore such a route for the Diameter request message and attempt
+   alternate routes if any exist.  In case all the candidate routes are
+   eliminated by the above criteria, the agent SHOULD return a
+   DIAMETER_UNABLE_TO_DELIVER message.
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 77]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
 6.1.8.  Redirecting Requests
 
@@ -4399,7 +4322,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    to REDIRECT, it MUST reply with an answer message with the 'E' bit
    set, while maintaining the Hop-by-Hop Identifier in the header, and
    include the Result-Code AVP to DIAMETER_REDIRECT_INDICATION.  Each of
-   the servers associated with the routing entry are added in separate
+   the servers associated with the routing entry are added in a separate
    Redirect-Host AVP.
 
                      +------------------+
@@ -4417,21 +4340,13 @@ Internet-Draft           Diameter Base Protocol             January 2011
                   |    Agent    |<-------------|    Server   |
                   +-------------+  4. Answer   +-------------+
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 79]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
                      Figure 5: Diameter Redirect Agent
 
-   The receiver of the answer message with the 'E' bit set, and the
-   Result-Code AVP set to DIAMETER_REDIRECT_INDICATION uses the hop-by-
-   hop field in the Diameter header to identify the request in the
-   pending message queue (see Section 5.3) that is to be redirected.  If
-   no transport connection exists with the new agent, one is created,
+   The receiver of an answer message with the 'E' bit set and the
+   Result-Code AVP set to DIAMETER_REDIRECT_INDICATION uses the Hop-by-
+   Hop Identifier in the Diameter header to identify the request in the
+   pending message queue (see Section 5.5.4) that is to be redirected.
+   If no transport connection exists with the new peer, one is created,
    and the request is sent directly to it.
 
    Multiple Redirect-Host AVPs are allowed.  The receiver of the answer
@@ -4440,17 +4355,26 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    When the Redirect-Host-Usage AVP included in the answer message has a
    non-zero value, a route entry for the redirect indications is created
-   and cached by the receiver.  The redirect usage for such route entry
-   is set by the value of Redirect-Host-Usage AVP and the lifetime of
-   the cached route entry is set by Redirect-Max-Cache-Time AVP value.
+   and cached by the receiver.  The redirect usage for such a route
+   entry is set by the value of Redirect-Host-Usage AVP and the lifetime
+   of the cached route entry is set by Redirect-Max-Cache-Time AVP
+   value.
 
    It is possible that multiple redirect indications can create multiple
    cached route entries differing only in their redirect usage and the
    peer to forward messages to.  As an example, two(2) route entries
    that are created by two(2) redirect indications results in two(2)
+
+
+
+Fajardo, et al.              Standards Track                   [Page 78]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    cached routes for the same realm and Application Id.  However, one
-   has a redirect usage of ALL_SESSION where matching request will be
-   forwarded to one peer and the other has a redirect usage of ALL_REALM
+   has a redirect usage of ALL_SESSION, where matching requests will be
+   forwarded to one peer; the other has a redirect usage of ALL_REALM,
    where request are forwarded to another peer.  Therefore, an incoming
    request that matches the realm and Application Id of both routes will
    need additional resolution.  In such a case, a routing precedence
@@ -4460,32 +4384,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 6.1.9.  Relaying and Proxying Requests
 
    A relay or proxy agent MUST append a Route-Record AVP to all requests
-   forwarded.  The AVP contains the identity of the peer the request was
-   received from.
+   forwarded.  The AVP contains the identity of the peer from which the
+   request was received.
 
-   The Hop-by-Hop identifier in the request is saved, and replaced with
-   a locally unique value.  The source of the request is also saved,
-   which includes the IP address, port and protocol.
+   The Hop-by-Hop Identifier in the request is saved and replaced with a
+   locally unique value.  The source of the request is also saved, which
+   includes the IP address, port, and protocol.
 
    A relay or proxy agent MAY include the Proxy-Info AVP in requests if
    it requires access to any local state information when the
    corresponding response is received.  The Proxy-Info AVP has security
-   implications as state information is distribute to other entities.
-   As such, it is RECOMMMENDED to protect the content of the Proxy-Info
-   AVP with cryptographic mechanisms, for example by using a keyed
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 80]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-   message digest.  Such a mechanism, however, requires the management
-   of keys, although only locally at the Diameter server.  Still, a full
-   description of the management of the keys used to protect the Proxy-
-   Info AVP is beyond the scope of this document.  Below is a list of
-   commonly recommended:
+   implications as state information is distributed to other entities.
+   As such, it is RECOMMENDED that the content of the Proxy-Info AVP be
+   protected with cryptographic mechanisms, for example, by using a
+   keyed message digest such as HMAC-SHA1 [RFC2104].  Such a mechanism,
+   however, requires the management of keys, although only locally at
+   the Diameter server.  Still, a full description of the management of
+   the keys used to protect the Proxy-Info AVP is beyond the scope of
+   this document.  Below is a list of common recommendations:
 
    o  The keys should be generated securely following the randomness
       recommendations in [RFC4086].
@@ -4494,32 +4410,39 @@ Internet-Draft           Diameter Base Protocol             January 2011
       least 128 bits in strength.
 
    o  The keys should not be used for any other purpose than generating
-      and verifying tickets.
+      and verifying instances of the Proxy-Info AVP.
 
    o  The keys should be changed regularly.
 
-   o  The keys should be changed if the ticket format or cryptographic
+   o  The keys should be changed if the AVP format or cryptographic
       protection algorithms change.
 
    The message is then forwarded to the next hop, as identified in the
-   Routing Table.
+   routing table.
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 79]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    Figure 6 provides an example of message routing using the procedures
    listed in these sections.
 
-        (Origin-Host=nas.example.net)    (Origin-Host=nas.example.net)
-        (Origin-Realm=example.net)       (Origin-Realm=example.net)
-        (Destination-Realm=example.com)  (Destination-
-                                            Realm=example.com)
+       (Origin-Host=nas.example.net)    (Origin-Host=nas.example.net)
+       (Origin-Realm=example.net)       (Origin-Realm=example.net)
+       (Destination-Realm=example.com)  (Destination-Realm=example.com)
                                         (Route-Record=nas.example.net)
-       +------+      ------>      +------+      ------>      +------+
-       |      |     (Request)     |      |      (Request)    |      |
-       | NAS  +-------------------+ DRL  +-------------------+ HMS  |
-       |      |                   |      |                   |      |
-       +------+     <------       +------+     <------       +------+
-      example.net    (Answer)   example.net     (Answer)   example.com
-           (Origin-Host=hms.example.com)   (Origin-Host=hms.example.com)
-           (Origin-Realm=example.com)      (Origin-Realm=example.com)
+      +------+      ------>      +------+      ------>      +------+
+      |      |     (Request)     |      |      (Request)    |      |
+      | NAS  +-------------------+ DRL  +-------------------+ HMS  |
+      |      |                   |      |                   |      |
+      +------+     <------       +------+     <------       +------+
+     example.net    (Answer)   example.net     (Answer)   example.com
+          (Origin-Host=hms.example.com)   (Origin-Host=hms.example.com)
+          (Origin-Realm=example.com)      (Origin-Realm=example.com)
 
                   Figure 6: Routing of Diameter messages
 
@@ -4527,15 +4450,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    incoming messages.  At a minimum, validation of the message header
    and relevant routing AVPs has to be done when relaying messages.
    Proxy agents may optionally perform more in-depth message validation
-   for applications it is interested in.
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 81]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+   for applications in which it is interested.
 
 6.2.  Diameter Answer Processing
 
@@ -4544,7 +4459,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    additional procedures that MAY be discussed in the Diameter
    application defining the command:
 
-   o  The same Hop-by-Hop identifier in the request is used in the
+   o  The same Hop-by-Hop Identifier in the request is used in the
       answer.
 
    o  The local host's identity is encoded in the Origin-Host AVP.
@@ -4561,15 +4476,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
    o  Any Proxy-Info AVPs in the request MUST be added to the answer
       message, in the same order they were present in the request.
 
+
+
+
+Fajardo, et al.              Standards Track                   [Page 80]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    o  The 'P' bit is set to the same value as the one in the request.
 
    o  The same End-to-End identifier in the request is used in the
       answer.
 
-   Note that the error messages (see Section 7.3) are also subjected to
+   Note that the error messages (see Section 7) are also subjected to
    the above processing rules.
 
-6.2.1.   Processing received Answers
+6.2.1.   Processing Received Answers
 
    A Diameter client or proxy MUST match the Hop-by-Hop Identifier in an
    answer received against the list of pending requests.  The
@@ -4579,31 +4502,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 6.2.2.  Relaying and Proxying Answers
 
-   If the answer is for a request which was proxied or relayed, the
-   agent MUST restore the original value of the Diameter header's Hop-
-   by-Hop Identifier field.
+   If the answer is for a request that was proxied or relayed, the agent
+   MUST restore the original value of the Diameter header's Hop-by-Hop
+   Identifier field.
 
    If the last Proxy-Info AVP in the message is targeted to the local
    Diameter server, the AVP MUST be removed before the answer is
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 82]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    forwarded.
 
    If a relay or proxy agent receives an answer with a Result-Code AVP
    indicating a failure, it MUST NOT modify the contents of the AVP.
-   Any additional local errors detected SHOULD be logged, but not
+   Any additional local errors detected SHOULD be logged but not
    reflected in the Result-Code AVP.  If the agent receives an answer
    message with a Result-Code AVP indicating success, and it wishes to
    modify the AVP to indicate an error, it MUST modify the Result-Code
    AVP to contain the appropriate error in the message destined towards
-   the access device as well as include the Error-Reporting-Host AVP and
-   it MUST issue an STR on behalf of the access device towards the
+   the access device as well as include the Error-Reporting-Host AVP; it
+   MUST also issue an STR on behalf of the access device towards the
    Diameter server.
 
    The agent MUST then send the answer to the host that it received the
@@ -4612,10 +4527,19 @@ Internet-Draft           Diameter Base Protocol             January 2011
 6.3.  Origin-Host AVP
 
    The Origin-Host AVP (AVP Code 264) is of type DiameterIdentity, and
-   MUST be present in all Diameter messages.  This AVP identifies the
+   it MUST be present in all Diameter messages.  This AVP identifies the
    endpoint that originated the Diameter message.  Relay agents MUST NOT
    modify this AVP.
 
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 81]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    The value of the Origin-Host AVP is guaranteed to be unique within a
    single host.
 
@@ -4638,17 +4562,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    The Destination-Host AVP (AVP Code 293) is of type DiameterIdentity.
    This AVP MUST be present in all unsolicited agent initiated messages,
-   MAY be present in request messages, and MUST NOT be present in Answer
+   MAY be present in request messages, and MUST NOT be present in answer
    messages.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 83]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    The absence of the Destination-Host AVP will cause a message to be
    sent to any Diameter server supporting the application within the
    realm specified in Destination-Realm AVP.
@@ -4658,20 +4574,28 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 6.6.  Destination-Realm AVP
 
-   The Destination-Realm AVP (AVP Code 283) is of type DiameterIdentity,
-   and contains the realm the message is to be routed to.  The
-   Destination-Realm AVP MUST NOT be present in Answer messages.
-   Diameter Clients insert the realm portion of the User-Name AVP.
+   The Destination-Realm AVP (AVP Code 283) is of type DiameterIdentity
+   and contains the realm to which the message is to be routed.  The
+   Destination-Realm AVP MUST NOT be present in answer messages.
+   Diameter clients insert the realm portion of the User-Name AVP.
    Diameter servers initiating a request message use the value of the
    Origin-Realm AVP from a previous message received from the intended
    target host (unless it is known a priori).  When present, the
    Destination-Realm AVP is used to perform message routing decisions.
 
-   An ABNF for a request message that includes the Destination-Realm AVP
+   The CCF for a request message that includes the Destination-Realm AVP
    SHOULD list the Destination-Realm AVP as a required AVP (an AVP
-   indicated as {AVP}) otherwise the message is inherently a non-
+   indicated as {AVP}); otherwise, the message is inherently a non-
    routable message.
 
+
+
+
+Fajardo, et al.              Standards Track                   [Page 82]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    This AVP SHOULD be placed as close to the Diameter header as
    possible.
 
@@ -4692,19 +4616,11 @@ Internet-Draft           Diameter Base Protocol             January 2011
    The Proxy-Info AVP (AVP Code 284) is of type Grouped.  This AVP
    contains the identity and local state information of the Diameter
    node that creates and adds it to a message.  The Grouped Data field
-   has the following ABNF grammar:
+   has the following CCF grammar:
 
          Proxy-Info ::= < AVP Header: 284 >
                         { Proxy-Host }
                         { Proxy-State }
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 84]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
                       * [ AVP ]
 
 6.7.3.  Proxy-Host AVP
@@ -4728,10 +4644,18 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Application-Id AVP MUST match the Application Id present in the
    Diameter message header.
 
+
+
+
+Fajardo, et al.              Standards Track                   [Page 83]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 6.9.  Acct-Application-Id AVP
 
    The Acct-Application-Id AVP (AVP Code 259) is of type Unsigned32 and
-   is used in order to advertise support of the Accounting portion of an
+   is used in order to advertise support of the accounting portion of an
    application (see Section 2.4).  If present in a message other than
    CER and CEA, the value of the Acct-Application-Id AVP MUST match the
    Application Id present in the Diameter message header.
@@ -4740,10 +4664,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    The Inband-Security-Id AVP (AVP Code 299) is of type Unsigned32 and
    is used in order to advertise support of the security portion of the
-   application.  The use of this AVP in CER and CEA messages is no
-   longer recommended.  Instead, discovery of a Diameter entities
-   security capabilities can be done either through static configuration
-   or via Diameter Peer Discovery described in Section 5.2.
+   application.  The use of this AVP in CER and CEA messages is NOT
+   RECOMMENDED.  Instead, discovery of a Diameter entity's security
+   capabilities can be done either through static configuration or via
+   Diameter Peer Discovery as described in Section 5.2.
 
    The following values are supported:
 
@@ -4753,36 +4677,37 @@ Internet-Draft           Diameter Base Protocol             January 2011
       This peer does not support TLS/TCP and DTLS/SCTP.  This is the
       default value, if the AVP is omitted.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 85]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    TLS 1
 
-      This node supports TLS/TCP and DTLS/SCTP security, as defined by
-      [RFC5246].
+      This node supports TLS/TCP [RFC5246] and DTLS/SCTP [RFC6083]
+      security.
 
 6.11.  Vendor-Specific-Application-Id AVP
 
    The Vendor-Specific-Application-Id AVP (AVP Code 260) is of type
    Grouped and is used to advertise support of a vendor-specific
-   Diameter Application.  Exactly one instance of either Auth-
+   Diameter application.  Exactly one instance of either Auth-
    Application-Id or Acct-Application-Id AVP MUST be present.  The
    Application Id carried by either Auth-Application-Id or Acct-
-   Application-Id AVP MUST comply with vendor specific Application Id
-   assignment described in Sec 11.3.  It MUST also match the Application
-   Id present in the Diameter header except when used in a CER or CEA
-   message.
+   Application-Id AVP MUST comply with vendor-specific Application Id
+   assignment described in Section 11.3.  It MUST also match the
+   Application Id present in the Diameter header except when used in a
+   CER or CEA message.
 
    The Vendor-Id AVP is an informational AVP pertaining to the vendor
    who may have authorship of the vendor-specific Diameter application.
    It MUST NOT be used as a means of defining a completely separate
    vendor-specific Application Id space.
 
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 84]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    The Vendor-Specific-Application-Id AVP SHOULD be placed as close to
    the Diameter header as possible.
 
@@ -4795,9 +4720,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    A Vendor-Specific-Application-Id AVP MUST contain exactly one of
    either Auth-Application-Id or Acct-Application-Id.  If a Vendor-
-   Specific-Application-Id is received without any of these two AVPs,
+   Specific-Application-Id is received without one of these two AVPs,
    then the recipient SHOULD issue an answer with a Result-Code set to
-   DIAMETER_MISSING_AVP.  The answer SHOULD also include a Failed-AVP
+   DIAMETER_MISSING_AVP.  The answer SHOULD also include a Failed-AVP,
    which MUST contain an example of an Auth-Application-Id AVP and an
    Acct-Application-Id AVP.
 
@@ -4805,22 +4730,13 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Auth-Application-Id and Acct-Application-Id, then the recipient MUST
    issue an answer with Result-Code set to
    DIAMETER_AVP_OCCURS_TOO_MANY_TIMES.  The answer MUST also include a
-   Failed-AVP which MUST contain the received Auth-Application-Id AVP
+   Failed-AVP, which MUST contain the received Auth-Application-Id AVP
    and Acct-Application-Id AVP.
 
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 86]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 6.12.  Redirect-Host AVP
 
    The Redirect-Host AVP (AVP Code 292) is of type DiameterURI.  One or
-   more of instances of this AVP MUST be present if the answer message's
+   more instances of this AVP MUST be present if the answer message's
    'E' bit is set and the Result-Code AVP is set to
    DIAMETER_REDIRECT_INDICATION.
 
@@ -4836,63 +4752,55 @@ Internet-Draft           Diameter Base Protocol             January 2011
    This AVP MAY be present in answer messages whose 'E' bit is set and
    the Result-Code AVP is set to DIAMETER_REDIRECT_INDICATION.
 
-   When present, this AVP provides a hints about how the routing entry
+   When present, this AVP provides hints about how the routing entry
    resulting from the Redirect-Host is to be used.  The following values
    are supported:
 
 
+
+
+Fajardo, et al.              Standards Track                   [Page 85]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    DONT_CACHE 0
 
       The host specified in the Redirect-Host AVP SHOULD NOT be cached.
       This is the default value.
 
-
    ALL_SESSION 1
 
       All messages within the same session, as defined by the same value
       of the Session-ID AVP SHOULD be sent to the host specified in the
       Redirect-Host AVP.
 
-
    ALL_REALM 2
 
       All messages destined for the realm requested SHOULD be sent to
       the host specified in the Redirect-Host AVP.
 
-
    REALM_AND_APPLICATION 3
 
       All messages for the application requested to the realm specified
       SHOULD be sent to the host specified in the Redirect-Host AVP.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 87]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    ALL_APPLICATION 4
 
       All messages for the application requested SHOULD be sent to the
       host specified in the Redirect-Host AVP.
 
-
    ALL_HOST 5
 
       All messages that would be sent to the host that generated the
       Redirect-Host SHOULD be sent to the host specified in the
-      Redirect- Host AVP.
-
+      Redirect-Host AVP.
 
    ALL_USER 6
 
       All messages for the user requested SHOULD be sent to the host
       specified in the Redirect-Host AVP.
 
-
-
    When multiple cached routes are created by redirect indications and
    they differ only in redirect usage and peers to forward requests to
    (see Section 6.1.8), a precedence rule MUST be applied to the
@@ -4902,6 +4810,16 @@ Internet-Draft           Diameter Base Protocol             January 2011
    other as they appear.  The order is as follows:
 
 
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 86]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    1.  ALL_SESSION
 
    2.  ALL_USER
@@ -4917,58 +4835,31 @@ Internet-Draft           Diameter Base Protocol             January 2011
 6.14.  Redirect-Max-Cache-Time AVP
 
    The Redirect-Max-Cache-Time AVP (AVP Code 262) is of type Unsigned32.
-   This AVP MUST be present in answer messages whose 'E' bit is set, the
-   Result-Code AVP is set to DIAMETER_REDIRECT_INDICATION and the
-   Redirect-Host-Usage AVP set to a non-zero value.
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 88]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+   This AVP MUST be present in answer messages whose 'E' bit is set,
+   whose Result-Code AVP is set to DIAMETER_REDIRECT_INDICATION, and
+   whose Redirect-Host-Usage AVP set to a non-zero value.
 
    This AVP contains the maximum number of seconds the peer and route
    table entries, created as a result of the Redirect-Host, SHOULD be
    cached.  Note that once a host is no longer reachable, any associated
-   cache, peer and routing table entries MUST be deleted.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
+   cache, peer, and routing table entries MUST be deleted.
 
+7.  Error Handling
 
+   There are two different types of errors in Diameter; protocol errors
+   and application errors.  A protocol error is one that occurs at the
+   base protocol level and MAY require per-hop attention (e.g., a
+   message routing error).  Application errors, on the other hand,
+   generally occur due to a problem with a function specified in a
+   Diameter application (e.g., user authentication, missing AVP).
 
+   Result-Code AVP values that are used to report protocol errors MUST
+   only be present in answer messages whose 'E' bit is set.  When a
+   request message is received that causes a protocol error, an answer
+   message is returned with the 'E' bit set, and the Result-Code AVP is
+   set to the appropriate protocol error value.  As the answer is sent
+   back towards the originator of the request, each proxy or relay agent
+   MAY take action on the message.
 
 
 
@@ -4980,27 +4871,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 89]
+Fajardo, et al.              Standards Track                   [Page 87]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-7.  Error Handling
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   There are two different types of errors in Diameter; protocol and
-   application errors.  A protocol error is one that occurs at the base
-   protocol level, and MAY require per hop attention (e.g., message
-   routing error).  Application errors, on the other hand, generally
-   occur due to a problem with a function specified in a Diameter
-   application (e.g., user authentication, missing AVP).
-
-   Result-Code AVP values that are used to report protocol errors MUST
-   only be present in answer messages whose 'E' bit is set.  When a
-   request message is received that causes a protocol error, an answer
-   message is returned with the 'E' bit set, and the Result-Code AVP is
-   set to the appropriate protocol error value.  As the answer is sent
-   back towards the originator of the request, each proxy or relay agent
-   MAY take action on the message.
 
                           1. Request        +---------+ Link Broken
                 +-------------------------->|Diameter |----///----+
@@ -5014,7 +4888,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
                                             | Relay 3 |-----------+
                                             +---------+
 
-        Figure 7: Example of Protocol Error causing answer message
+        Figure 7: Example of Protocol Error Causing Answer Message
 
    Figure 7 provides an example of a message forwarded upstream by a
    Diameter relay.  When the message is received by Relay 2, and it
@@ -5032,40 +4906,40 @@ Internet-Draft           Diameter Base Protocol             January 2011
             +---------+  4. Answer  +---------+  3. Answer  +---------+
                        (Missing AVP)           (Missing AVP)
 
-           Figure 8: Example of Application Error Answer message
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 90]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+           Figure 8: Example of Application Error Answer Message
 
    Figure 8 provides an example of a Diameter message that caused an
    application error.  When application errors occur, the Diameter
-   entity reporting the error clears the 'R' bit in the Command Flags,
+   entity reporting the error clears the 'R' bit in the Command Flags
    and adds the Result-Code AVP with the proper value.  Application
-   errors do not require any proxy or relay agent involvement, and
-   therefore the message would be forwarded back to the originator of
+   errors do not require any proxy or relay agent involvement;
+   therefore, the message would be forwarded back to the originator of
    the request.
 
    In the case where the answer message itself contains errors, any
    related session SHOULD be terminated by sending an STR or ASR
    message.  The Termination-Cause AVP in the STR MAY be filled with the
    appropriate value to indicate the cause of the error.  An application
-   MAY also send an application-specific request instead of STR or ASR
-   to signal the error in the case where no state is maintained or to
-   allow for some form of error recovery with the corresponding Diameter
-   entity.
+   MAY also send an application-specific request instead of an STR or
+   ASR message to signal the error in the case where no state is
+   maintained or to allow for some form of error recovery with the
+   corresponding Diameter entity.
+
+
+
+Fajardo, et al.              Standards Track                   [Page 88]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    There are certain Result-Code AVP application errors that require
    additional AVPs to be present in the answer.  In these cases, the
    Diameter node that sets the Result-Code AVP to indicate the error
-   MUST add the AVPs.  Examples are:
+   MUST add the AVPs.  Examples are as follows:
 
    o  A request with an unrecognized AVP is received with the 'M' bit
-      (Mandatory bit) set, causes an answer to be sent with the Result-
-      Code AVP set to DIAMETER_AVP_UNSUPPORTED, and the Failed-AVP AVP
+      (Mandatory bit) set causes an answer to be sent with the Result-
+      Code AVP set to DIAMETER_AVP_UNSUPPORTED and the Failed-AVP AVP
       containing the offending AVP.
 
    o  A request with an AVP that is received with an unrecognized value
@@ -5073,46 +4947,46 @@ Internet-Draft           Diameter Base Protocol             January 2011
       DIAMETER_INVALID_AVP_VALUE, with the Failed-AVP AVP containing the
       AVP causing the error.
 
-   o  A received command which is missing AVP(s) that are defined as
-      required in the commands ABNF; examples are AVPs indicated as
+   o  A received command that is missing AVPs that are defined as
+      required in the commands CCF; examples are AVPs indicated as
       {AVP}.  The receiver issues an answer with the Result-Code set to
-      DIAMETER_MISSING_AVP, and creates an AVP with the AVP Code and
+      DIAMETER_MISSING_AVP and creates an AVP with the AVP Code and
       other fields set as expected in the missing AVP.  The created AVP
-      is then added to the Failed- AVP AVP.
+      is then added to the Failed-AVP AVP.
 
    The Result-Code AVP describes the error that the Diameter node
    encountered in its processing.  In case there are multiple errors,
    the Diameter node MUST report only the first error it encountered
-   (detected possibly in some implementation dependent order).  The
+   (detected possibly in some implementation-dependent order).  The
    specific errors that can be described by this AVP are described in
    the following section.
 
+7.1.  Result-Code AVP
 
+   The Result-Code AVP (AVP Code 268) is of type Unsigned32 and
+   indicates whether a particular request was completed successfully or
+   an error occurred.  All Diameter answer messages in IETF-defined
+   Diameter application specifications MUST include one Result-Code AVP.
+   A non-successful Result-Code AVP (one containing a non-2xxx value
+   other than DIAMETER_REDIRECT_INDICATION) MUST include the Error-
+   Reporting-Host AVP if the host setting the Result-Code AVP is
+   different from the identity encoded in the Origin-Host AVP.
 
+   The Result-Code data field contains an IANA-managed 32-bit address
+   space representing errors (see Section 11.3.2).  Diameter provides
+   the following classes of errors, all identified by the thousands
+   digit in the decimal notation:
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 91]
-
-Internet-Draft           Diameter Base Protocol             January 2011
 
 
-7.1.  Result-Code AVP
 
-   The Result-Code AVP (AVP Code 268) is of type Unsigned32 and
-   indicates whether a particular request was completed successfully or
-   whether an error occurred.  All Diameter answer messages in IETF
-   defined Diameter application specification MUST include one Result-
-   Code AVP.  A non-successful Result-Code AVP (one containing a non
-   2xxx value other than DIAMETER_REDIRECT_INDICATION) MUST include the
-   Error-Reporting-Host AVP if the host setting the Result-Code AVP is
-   different from the identity encoded in the Origin-Host AVP.
 
+Fajardo, et al.              Standards Track                   [Page 89]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   The Result-Code data field contains an IANA-managed 32-bit address
-   space representing errors (see Section 11.4).  Diameter provides the
-   following classes of errors, all identified by the thousands digit in
-   the decimal notation:
 
    o  1xxx (Informational)
 
@@ -5124,7 +4998,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    o  5xxx (Permanent Failure)
 
-   A non-recognized class (one whose first digit is not defined in this
+   An unrecognized class (one whose first digit is not defined in this
    section) MUST be handled as a permanent failure.
 
 7.1.1.  Informational
@@ -5133,7 +5007,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
    requester that a request could not be satisfied, and additional
    action is required on its part before access is granted.
 
-
    DIAMETER_MULTI_ROUND_AUTH 1001
 
       This informational error is returned by a Diameter server to
@@ -5141,24 +5014,11 @@ Internet-Draft           Diameter Base Protocol             January 2011
       used requires multiple round trips, and a subsequent request needs
       to be issued in order for access to be granted.
 
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 92]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 7.1.2.  Success
 
    Errors that fall within the Success category are used to inform a
    peer that a request has been successfully completed.
 
-
    DIAMETER_SUCCESS 2001
 
       The request was successfully completed.
@@ -5174,27 +5034,33 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Errors that fall within the Protocol Error category SHOULD be treated
    on a per-hop basis, and Diameter proxies MAY attempt to correct the
    error, if it is possible.  Note that these errors MUST only be used
-   in answer messages whose 'E' bit is set.  This document omits some
-   error codes defined in [RFC3588].  To provide backward compatibility
-   with [RFC3588] implementations these error code values are not re-
-   used and hence the error codes values enumerated below are non-
-   sequential.
+   in answer messages whose 'E' bit is set.
+
 
 
+
+Fajardo, et al.              Standards Track                   [Page 90]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   DIAMETER_COMMAND_UNSUPPORTED 3001
+
+      This error code is used when a Diameter entity receives a message
+      with a Command Code that it does not support.
+
    DIAMETER_UNABLE_TO_DELIVER 3002
 
-      This error is given when Diameter can not deliver the message to
+      This error is given when Diameter cannot deliver the message to
       the destination, either because no host within the realm
       supporting the required application was available to process the
-      request, or because Destination-Host AVP was given without the
+      request or because the Destination-Host AVP was given without the
       associated Destination-Realm AVP.
 
-
    DIAMETER_REALM_NOT_SERVED 3003
 
       The intended realm of the request is not recognized.
 
-
    DIAMETER_TOO_BUSY 3004
 
       When returned, a Diameter node SHOULD attempt to send the message
@@ -5202,13 +5068,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
       specific server is requested, and it cannot provide the requested
       service.
 
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 93]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    DIAMETER_LOOP_DETECTED 3005
 
       An agent detected a loop while trying to get the message to the
@@ -5216,121 +5075,110 @@ Internet-Draft           Diameter Base Protocol             January 2011
       if one is available, but the peer reporting the error has
       identified a configuration problem.
 
-
    DIAMETER_REDIRECT_INDICATION 3006
 
       A redirect agent has determined that the request could not be
-      satisfied locally and the initiator of the request SHOULD direct
+      satisfied locally, and the initiator of the request SHOULD direct
       the request directly to the server, whose contact information has
       been added to the response.  When set, the Redirect-Host AVP MUST
       be present.
 
-
    DIAMETER_APPLICATION_UNSUPPORTED 3007
 
       A request was sent for an application that is not supported.
 
+   DIAMETER_INVALID_HDR_BITS 3008
 
-   DIAMETER_INVALID_BIT_IN_HEADER 3011
+      A request was received whose bits in the Diameter header were set
+      either to an invalid combination or to a value that is
+      inconsistent with the Command Code's definition.
 
-      This error is returned when a reserved bit in the Diameter header
-      is set to one (1) or the bits in the Diameter header defined in
-      Section 3 are set incorrectly.
 
 
-   DIAMETER_INVALID_MESSAGE_LENGTH 3012
+Fajardo, et al.              Standards Track                   [Page 91]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-      This error is returned when a request is received with an invalid
-      message length.
 
+   DIAMETER_INVALID_AVP_BITS 3009
+
+      A request was received that included an AVP whose flag bits are
+      set to an unrecognized value or that is inconsistent with the
+      AVP's definition.
+
+   DIAMETER_UNKNOWN_PEER 3010
+
+      A CER was received from an unknown peer.
 
 7.1.4.  Transient Failures
 
    Errors that fall within the transient failures category are used to
    inform a peer that the request could not be satisfied at the time it
-   was received, but MAY be able to satisfy the request in the future.
+   was received but MAY be able to satisfy the request in the future.
    Note that these errors MUST be used in answer messages whose 'E' bit
    is not set.
 
-
    DIAMETER_AUTHENTICATION_REJECTED 4001
 
       The authentication process for the user failed, most likely due to
       an invalid password used by the user.  Further attempts MUST only
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 94]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       be tried after prompting the user for a new password.
 
-
    DIAMETER_OUT_OF_SPACE 4002
 
       A Diameter node received the accounting request but was unable to
       commit it to stable storage due to a temporary lack of space.
 
-
    ELECTION_LOST 4003
 
       The peer has determined that it has lost the election process and
       has therefore disconnected the transport connection.
 
-
 7.1.5.  Permanent Failures
 
    Errors that fall within the permanent failures category are used to
-   inform the peer that the request failed, and should not be attempted
+   inform the peer that the request failed and should not be attempted
    again.  Note that these errors SHOULD be used in answer messages
    whose 'E' bit is not set.  In error conditions where it is not
-   possible or efficient to compose application-specific answer grammar
-   then answer messages with E-bit set and complying to the grammar
-   described in 7.2 MAY also be used for permanent errors.
+   possible or efficient to compose application-specific answer grammar,
+   answer messages with the 'E' bit set and which comply to the grammar
+   described in Section 7.2 MAY also be used for permanent errors.
 
-   To provide backward compatibility with existing implementations that
-   follow [RFC3588], some of the error values that have previously been
-   used in this category by [RFC3588] will not be re-used.  Therefore
-   the error values enumerated here may be non-sequential.
 
 
-   DIAMETER_AVP_UNSUPPORTED 5001
 
-      The peer received a message that contained an AVP that is not
-      recognized or supported and was marked with the Mandatory bit.  A
-      Diameter message with this error MUST contain one or more Failed-
-      AVP AVP containing the AVPs that caused the failure.
 
 
-   DIAMETER_UNKNOWN_SESSION_ID 5002
 
-      The request contained an unknown Session-Id.
 
+Fajardo, et al.              Standards Track                   [Page 92]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   DIAMETER_AUTHORIZATION_REJECTED 5003
 
-      A request was received for which the user could not be authorized.
-      This error could occur if the service requested is not permitted
+   DIAMETER_AVP_UNSUPPORTED 5001
 
+      The peer received a message that contained an AVP that is not
+      recognized or supported and was marked with the 'M' (Mandatory)
+      bit.  A Diameter message with this error MUST contain one or more
+      Failed-AVP AVPs containing the AVPs that caused the failure.
 
+   DIAMETER_UNKNOWN_SESSION_ID 5002
 
-Fajardo, et al.           Expires July 24, 2011                [Page 95]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+      The request contained an unknown Session-Id.
 
+   DIAMETER_AUTHORIZATION_REJECTED 5003
 
+      A request was received for which the user could not be authorized.
+      This error could occur if the service requested is not permitted
       to the user.
 
-
    DIAMETER_INVALID_AVP_VALUE 5004
 
       The request contained an AVP with an invalid value in its data
       portion.  A Diameter message indicating this error MUST include
       the offending AVPs within a Failed-AVP AVP.
 
-
    DIAMETER_MISSING_AVP 5005
 
       The request did not contain an AVP that is required by the Command
@@ -5340,21 +5188,28 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Vendor-Id if applicable.  The value field of the missing AVP
       should be of correct minimum length and contain zeroes.
 
-
    DIAMETER_RESOURCES_EXCEEDED 5006
 
       A request was received that cannot be authorized because the user
       has already expended allowed resources.  An example of this error
-      condition is a user that is restricted to one dial-up PPP port,
-      attempts to establish a second PPP connection.
-
+      condition is when a user that is restricted to one dial-up PPP
+      port attempts to establish a second PPP connection.
 
    DIAMETER_CONTRADICTING_AVPS 5007
 
       The Home Diameter server has detected AVPs in the request that
-      contradicted each other, and is not willing to provide service to
-      the user.  The Failed-AVP AVPs MUST be present which contains the
-      AVPs that contradicted each other.
+      contradicted each other, and it is not willing to provide service
+      to the user.  The Failed-AVP AVP MUST be present, which contain
+      the AVPs that contradicted each other.
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                   [Page 93]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    DIAMETER_AVP_NOT_ALLOWED 5008
@@ -5363,22 +5218,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Failed-AVP AVP MUST be included and contain a copy of the
       offending AVP.
 
-
    DIAMETER_AVP_OCCURS_TOO_MANY_TIMES 5009
 
       A message was received that included an AVP that appeared more
       often than permitted in the message definition.  The Failed-AVP
       AVP MUST be included and contain a copy of the first instance of
-
-
-
-Fajardo, et al.           Expires July 24, 2011                [Page 96]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-      the offending AVP that exceeded the maximum number of occurrences
-
+      the offending AVP that exceeded the maximum number of occurrences.
 
    DIAMETER_NO_COMMON_APPLICATION 5010
 
@@ -5386,18 +5231,21 @@ Internet-Draft           Diameter Base Protocol             January 2011
       whereby no applications are common between the CER sending peer
       and the CER receiving peer.
 
-
    DIAMETER_UNSUPPORTED_VERSION 5011
 
       This error is returned when a request was received, whose version
       number is unsupported.
 
-
    DIAMETER_UNABLE_TO_COMPLY 5012
 
       This error is returned when a request is rejected for unspecified
       reasons.
 
+   DIAMETER_INVALID_BIT_IN_HEADER 5013
+
+      This error is returned when a reserved bit in the Diameter header
+      is set to one (1) or the bits in the Diameter header are set
+      incorrectly.
 
    DIAMETER_INVALID_AVP_LENGTH 5014
 
@@ -5407,56 +5255,41 @@ Internet-Draft           Diameter Base Protocol             January 2011
       value exceeds the message length or is less than the minimum AVP
       header length, it is sufficient to include the offending AVP
       header and a zero filled payload of the minimum required length
-      for the payloads data type.  If the AVP is a grouped AVP, the
-      grouped AVP header with an empty payload would be sufficient to
+      for the payloads data type.  If the AVP is a Grouped AVP, the
+      Grouped AVP header with an empty payload would be sufficient to
       indicate the offending AVP.  In the case where the offending AVP
       header cannot be fully decoded when the AVP length is less than
-      the minimum AVP header length, it is sufficient to include an
-      offending AVP header that is formulated by padding the incomplete
-      AVP header with zero up to the minimum AVP header length.
-
-
-   DIAMETER_NO_COMMON_SECURITY 5017
-
-      This error is returned when a CER message is received, and there
-      are no common security mechanisms supported between the peers.  A
-      Capabilities-Exchange-Answer (CEA) MUST be returned with the
-      Result-Code AVP set to DIAMETER_NO_COMMON_SECURITY.
-
-
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 97]
+Fajardo, et al.              Standards Track                   [Page 94]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   DIAMETER_UNKNOWN_PEER 5018
-
-      A CER was received from an unknown peer.
-
-
-   DIAMETER_COMMAND_UNSUPPORTED 5019
-
-      This error code is used when a Diameter entity receives a message
-      with a Command Code that it does not support.
-
+      the minimum AVP header length, it is sufficient to include an
+      offending AVP header that is formulated by padding the incomplete
+      AVP header with zero up to the minimum AVP header length.
 
-   DIAMETER_INVALID_HDR_BITS 5020
+   DIAMETER_INVALID_MESSAGE_LENGTH 5015
 
-      A request was received whose bits in the Diameter header were
-      either set to an invalid combination, or to a value that is
-      inconsistent with the command code's definition.
+      This error is returned when a request is received with an invalid
+      message length.
 
+   DIAMETER_INVALID_AVP_BIT_COMBO 5016
 
-   DIAMETER_INVALID_AVP_BITS 5021
+      The request contained an AVP with which is not allowed to have the
+      given value in the AVP Flags field.  A Diameter message indicating
+      this error MUST include the offending AVPs within a Failed-AVP
+      AVP.
 
-      A request was received that included an AVP whose flag bits are
-      set to an unrecognized value, or that is inconsistent with the
-      AVP's definition.
+   DIAMETER_NO_COMMON_SECURITY 5017
 
+      This error is returned when a CER message is received, and there
+      are no common security mechanisms supported between the peers.  A
+      Capabilities-Exchange-Answer (CEA) message MUST be returned with
+      the Result-Code AVP set to DIAMETER_NO_COMMON_SECURITY.
 
 7.2.  Error Bit
 
@@ -5465,12 +5298,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the 'E' bit MUST NOT be sent as a response to an answer message.
    Note that a message with the 'E' bit set is still subjected to the
    processing rules defined in Section 6.2.  When set, the answer
-   message will not conform to the ABNF specification for the command,
-   and will instead conform to the following ABNF:
+   message will not conform to the CCF specification for the command;
+   instead, it and will conform to the following CCF:
 
       Message Format
 
-      <answer-message> ::= < Diameter Header: code, ERR [PXY] >
+      <answer-message> ::= < Diameter Header: code, ERR [, PXY] >
                         0*1< Session-Id >
                            { Origin-Host }
                            { Origin-Realm }
@@ -5481,16 +5314,16 @@ Internet-Draft           Diameter Base Protocol             January 2011
                            [ Failed-AVP ]
                            [ Experimental-Result ]
                          * [ Proxy-Info ]
+                         * [ AVP ]
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 98]
+
+Fajardo, et al.              Standards Track                   [Page 95]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-                         * [ AVP ]
-
    Note that the code used in the header is the same than the one found
    in the request message, but with the 'R' bit cleared and the 'E' bit
    set.  The 'P' bit in the header is set to the same value as the one
@@ -5499,10 +5332,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 7.3.  Error-Message AVP
 
    The Error-Message AVP (AVP Code 281) is of type UTF8String.  It MAY
-   accompany a Result-Code AVP as a human readable error message.  The
+   accompany a Result-Code AVP as a human-readable error message.  The
    Error-Message AVP is not intended to be useful in an environment
    where error messages are processed automatically.  It SHOULD NOT be
-   expected that the content of this AVP is parsed by network entities.
+   expected that the content of this AVP be parsed by network entities.
 
 7.4.  Error-Reporting-Host AVP
 
@@ -5511,8 +5344,8 @@ Internet-Draft           Diameter Base Protocol             January 2011
    host that sent the Result-Code AVP to a value other than 2001
    (Success), only if the host setting the Result-Code is different from
    the one encoded in the Origin-Host AVP.  This AVP is intended to be
-   used for troubleshooting purposes, and MUST be set when the Result-
-   Code AVP indicates a failure.
+   used for troubleshooting purposes, and it MUST be set when the
+   Result-Code AVP indicates a failure.
 
 7.5.  Failed-AVP AVP
 
@@ -5520,43 +5353,44 @@ Internet-Draft           Diameter Base Protocol             January 2011
    debugging information in cases where a request is rejected or not
    fully processed due to erroneous information in a specific AVP.  The
    value of the Result-Code AVP will provide information on the reason
-   for the Failed-AVP AVP.  A Diameter message SHOULD contain only one
-   Failed-AVP that corresponds to the error indicated by the Result-Code
-   AVP.  For practical purposes, this Failed-AVP would typically refer
-   to the first AVP processing error that a Diameter node encounters.
+   for the Failed-AVP AVP.  A Diameter answer message SHOULD contain an
+   instance of the Failed-AVP AVP that corresponds to the error
+   indicated by the Result-Code AVP.  For practical purposes, this
+   Failed-AVP would typically refer to the first AVP processing error
+   that a Diameter node encounters.
 
    The possible reasons for this AVP are the presence of an improperly
    constructed AVP, an unsupported or unrecognized AVP, an invalid AVP
    value, the omission of a required AVP, the presence of an explicitly
-   excluded AVP (see tables in Section 10), or the presence of two or
-   more occurrences of an AVP which is restricted to 0, 1, or 0-1
+   excluded AVP (see tables in Section 10) or the presence of two or
+   more occurrences of an AVP that is restricted to 0, 1, or 0-1
    occurrences.
 
    A Diameter message SHOULD contain one Failed-AVP AVP, containing the
    entire AVP that could not be processed successfully.  If the failure
    reason is omission of a required AVP, an AVP with the missing AVP
-   code, the missing vendor id, and a zero filled payload of the minimum
+   code, the missing Vendor-Id, and a zero-filled payload of the minimum
    required length for the omitted AVP will be added.  If the failure
+   reason is an invalid AVP length where the reported length is less
 
 
 
-Fajardo, et al.           Expires July 24, 2011                [Page 99]
+Fajardo, et al.              Standards Track                   [Page 96]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   reason is an invalid AVP length where the reported length is less
    than the minimum AVP header length or greater than the reported
-   message length, a copy of the offending AVP header and a zero filled
+   message length, a copy of the offending AVP header and a zero-filled
    payload of the minimum required length SHOULD be added.
 
-   In the case where the offending AVP is embedded within a grouped AVP,
-   the Failed-AVP MAY contain the grouped AVP which in turn contains the
-   single offending AVP.  The same method MAY be employed if the grouped
-   AVP itself is embedded in yet another grouped AVP and so on.  In this
-   case, the Failed-AVP MAY contain the grouped AVP hierarchy up to the
-   single offending AVP.  This enables the recipient to detect the
-   location of the offending AVP when embedded in a group.
+   In the case where the offending AVP is embedded within a Grouped AVP,
+   the Failed-AVP MAY contain the grouped AVP, which in turn contains
+   the single offending AVP.  The same method MAY be employed if the
+   grouped AVP itself is embedded in yet another grouped AVP and so on.
+   In this case, the Failed-AVP MAY contain the grouped AVP hierarchy up
+   to the single offending AVP.  This enables the recipient to detect
+   the location of the offending AVP when embedded in a group.
 
    AVP Format
 
@@ -5577,7 +5411,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
                                  { Experimental-Result-Code }
 
    The Vendor-Id AVP (see Section 5.3.3) in this grouped AVP identifies
-   the vendor responsible for the assignment of the result code which
+   the vendor responsible for the assignment of the result code that
    follows.  All Diameter answer messages defined in vendor-specific
    applications MUST include either one Result-Code AVP or one
    Experimental-Result AVP.
@@ -5590,23 +5424,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    It is recommended that vendor-specific result codes follow the same
    conventions given for the Result-Code AVP regarding the different
-   types of result codes and the handling of errors (for non 2xxx
+   types of result codes and the handling of errors (for non-2xxx
    values).
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 100]
+
+Fajardo, et al.              Standards Track                   [Page 97]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 8.  Diameter User Sessions
 
    In general, Diameter can provide two different types of services to
    applications.  The first involves authentication and authorization,
-   and can optionally make use of accounting.  The second only makes use
-   of accounting.
+   and it can optionally make use of accounting.  The second only makes
+   use of accounting.
 
    When a service makes use of the authentication and/or authorization
    portion of an application, and a user requests access to the network,
@@ -5614,27 +5449,28 @@ Internet-Draft           Diameter Base Protocol             January 2011
    auth request is defined in a service-specific Diameter application
    (e.g., NASREQ).  The request contains a Session-Id AVP, which is used
    in subsequent messages (e.g., subsequent authorization, accounting,
-   etc) relating to the user's session.  The Session-Id AVP is a means
+   etc.) relating to the user's session.  The Session-Id AVP is a means
    for the client and servers to correlate a Diameter message with a
    user session.
 
-   When a Diameter server authorizes a user to use network resources for
-   a finite amount of time, and it is willing to extend the
-   authorization via a future request, it MUST add the Authorization-
-   Lifetime AVP to the answer message.  The Authorization-Lifetime AVP
-   defines the maximum number of seconds a user MAY make use of the
-   resources before another authorization request is expected by the
-   server.  The Auth-Grace-Period AVP contains the number of seconds
-   following the expiration of the Authorization-Lifetime, after which
-   the server will release all state information related to the user's
-   session.  Note that if payment for services is expected by the
-   serving realm from the user's home realm, the Authorization-Lifetime
-   AVP, combined with the Auth-Grace-Period AVP, implies the maximum
-   length of the session the home realm is willing to be fiscally
-   responsible for.  Services provided past the expiration of the
-   Authorization-Lifetime and Auth-Grace-Period AVPs are the
-   responsibility of the access device.  Of course, the actual cost of
-   services rendered is clearly outside the scope of the protocol.
+   When a Diameter server authorizes a user to implement network
+   resources for a finite amount of time, and it is willing to extend
+   the authorization via a future request, it MUST add the
+   Authorization- Lifetime AVP to the answer message.  The
+   Authorization-Lifetime AVP defines the maximum number of seconds a
+   user MAY make use of the resources before another authorization
+   request is expected by the server.  The Auth-Grace-Period AVP
+   contains the number of seconds following the expiration of the
+   Authorization-Lifetime, after which the server will release all state
+   information related to the user's session.  Note that if payment for
+   services is expected by the serving realm from the user's home realm,
+   the Authorization-Lifetime AVP, combined with the Auth-Grace-Period
+   AVP, implies the maximum length of the session for which the home
+   realm is willing to be fiscally responsible.  Services provided past
+   the expiration of the Authorization-Lifetime and Auth-Grace-Period
+   AVPs are the responsibility of the access device.  Of course, the
+   actual cost of services rendered is clearly outside the scope of the
+   protocol.
 
    An access device that does not expect to send a re-authorization or a
    session termination request to the server MAY include the Auth-
@@ -5648,32 +5484,33 @@ Internet-Draft           Diameter Base Protocol             January 2011
    value NO_STATE_MAINTAINED MUST NOT be set in subsequent re-
    authorization requests and answers.
 
-   The base protocol does not include any authorization request
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 101]
+Fajardo, et al.              Standards Track                   [Page 98]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+   The base protocol does not include any authorization request
    messages, since these are largely application-specific and are
    defined in a Diameter application document.  However, the base
    protocol does define a set of messages that are used to terminate
    user sessions.  These are used to allow servers that maintain state
    information to free resources.
 
-   When a service only makes use of the Accounting portion of the
+   When a service only makes use of the accounting portion of the
    Diameter protocol, even in combination with an application, the
    Session-Id is still used to identify user sessions.  However, the
    session termination messages are not used, since a session is
    signaled as being terminated by issuing an accounting stop message.
 
    Diameter may also be used for services that cannot be easily
-   categorized as authentication, authorization or accounting (e.g.,
-   certain 3GPP IMS interfaces).  In such cases, the finite state
+   categorized as authentication, authorization, or accounting (e.g.,
+   certain Third Generation Partnership Project Internet Multimedia
+   System (3GPP IMS) interfaces).  In such cases, the finite state
    machine defined in subsequent sections may not be applicable.
-   Therefore, the applications itself MAY need to define its own finite
+   Therefore, the application itself MAY need to define its own finite
    state machine.  However, such application-specific state machines
    SHOULD follow the general state machine framework outlined in this
    document such as the use of Session-Id AVPs and the use of STR/STA,
@@ -5681,12 +5518,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 8.1.  Authorization Session State Machine
 
-   This section contains a set of finite state machines, representing
-   the life cycle of Diameter sessions, and which MUST be observed by
-   all Diameter implementations that make use of the authentication
-   and/or authorization portion of a Diameter application.  The term
-   Service-Specific below refers to a message defined in a Diameter
-   application (e.g., Mobile IPv4, NASREQ).
+   This section contains a set of finite state machines, which represent
+   the life cycle of Diameter sessions and which MUST be observed by all
+   Diameter implementations that make use of the authentication and/or
+   authorization portion of a Diameter application.  The term "Service-
+   Specific" below refers to a message defined in a Diameter application
+   (e.g., Mobile IPv4, NASREQ).
 
    There are four different authorization session state machines
    supported in the Diameter base protocol.  The first two describe a
@@ -5700,26 +5537,25 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    When a session is moved to the Idle state, any resources that were
    allocated for the particular session must be released.  Any event not
-   listed in the state machines MUST be considered as an error
-   condition, and an answer, if applicable, MUST be returned to the
-   originator of the message.
+   listed in the state machines MUST be considered an error condition,
+   and an answer, if applicable, MUST be returned to the originator of
+   the message.
 
-   In the case that an application does not support re-auth, the state
 
 
-
-Fajardo, et al.           Expires July 24, 2011               [Page 102]
+Fajardo, et al.              Standards Track                   [Page 99]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   transitions related to server-initiated re-auth when both client and
-   server session maintains state (e.g., Send RAR, Pending, Receive RAA)
-   MAY be ignored.
+   In the case that an application does not support re-auth, the state
+   transitions related to server-initiated re-auth, when both client and
+   server sessions maintain state (e.g., Send RAR, Pending, Receive
+   RAA), MAY be ignored.
 
-   In the state table, the event 'Failure to send X' means that the
+   In the state table, the event "Failure to send X" means that the
    Diameter agent is unable to send command X to the desired
-   destination.  This could be due to the peer being down, or due to the
+   destination.  This could be due to the peer being down or due to the
    peer sending back a transient failure or temporary protocol error
    notification DIAMETER_TOO_BUSY or DIAMETER_LOOP_DETECTED in the
    Result-Code AVP of the corresponding Answer command.  The event 'X
@@ -5731,8 +5567,8 @@ Internet-Draft           Diameter Base Protocol             January 2011
                               CLIENT, STATEFUL
       State     Event                          Action       New State
       ---------------------------------------------------------------
-      Idle      Client or Device Requests      Send         Pending
-                access                         service
+      Idle      Client or device requests      Send         Pending
+                access                         service-
                                                specific
                                                auth req
 
@@ -5748,39 +5584,38 @@ Internet-Draft           Diameter Base Protocol             January 2011
                                                UNKNOWN_
                                                SESSION_ID
 
-      Pending   Successful Service-specific    Grant        Open
+      Pending   Successful service-specific    Grant        Open
                 authorization answer           Access
                 received with default
                 Auth-Session-State value
 
-      Pending   Successful Service-specific    Sent STR     Discon
-                authorization answer received
+      Pending   Successful service-specific    Sent STR     Discon
+                authorization answer received,
                 but service not provided
 
       Pending   Error processing successful    Sent STR     Discon
-                Service-specific authorization
+                service-specific authorization
                 answer
 
 
 
-
-Fajardo, et al.           Expires July 24, 2011               [Page 103]
+Fajardo, et al.              Standards Track                  [Page 100]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-      Pending   Failed Service-specific        Cleanup      Idle
+      Pending   Failed service-specific        Clean up     Idle
                 authorization answer received
 
       Open      User or client device          Send         Open
-                requests access to service     service
+                requests access to service     service-
                                                specific
                                                auth req
 
-      Open      Successful Service-specific    Provide      Open
-                authorization answer received  Service
+      Open      Successful service-specific    Provide      Open
+                authorization answer received  service
 
-      Open      Failed Service-specific        Discon.      Idle
+      Open      Failed service-specific        Discon.      Idle
                 authorization answer           user/device
                 received.
 
@@ -5796,10 +5631,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
                                                Discon.
                                                user/device
 
-      Open      Session-Timeout Expires on     Send STR     Discon
-                Access Device
+      Open      Session-Timeout expires on     Send STR     Discon
+                access device
 
-      Open      ASR Received,                  Send ASA     Discon
+      Open      ASR received,                  Send ASA     Discon
                 client will comply             with
                 with request to end the        Result-Code =
                 session                        = SUCCESS,
@@ -5814,17 +5649,18 @@ Internet-Draft           Diameter Base Protocol             January 2011
                 Auth-Grace-Period expires on
                 access device
 
-      Discon    ASR Received                   Send ASA     Discon
+      Discon    ASR received                   Send ASA     Discon
+
 
-      Discon    STA Received                   Discon.      Idle
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 104]
+Fajardo, et al.              Standards Track                  [Page 101]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+      Discon    STA received                   Discon.      Idle
                                                user/device
 
    The following state machine is observed by a server when it is
@@ -5835,31 +5671,34 @@ Internet-Draft           Diameter Base Protocol             January 2011
       ---------------------------------------------------------------
       Idle      Service-specific authorization Send         Open
                 request received, and          successful
-                user is authorized             serv.
+                user is authorized             service-
                                                specific
                                                answer
 
       Idle      Service-specific authorization Send         Idle
-                request received, and          failed serv.
-                user is not authorized         specific
+                request received, and          failed
+                user is not authorized         service-
+                                               specific
                                                answer
 
       Open      Service-specific authorization Send         Open
                 request received, and user     successful
-                is authorized                  serv. specific
+                is authorized                  service-
+                                               specific
                                                answer
 
       Open      Service-specific authorization Send         Idle
-                request received, and user     failed serv.
-                is not authorized              specific
+                request received, and user     failed
+                is not authorized              service-
+                                               specific
                                                answer,
-                                               Cleanup
+                                               Clean up
 
       Open      Home server wants to confirm   Send RAR     Pending
                 authentication and/or
                 authorization of the user
 
-      Pending   Received RAA with a failed     Cleanup      Idle
+      Pending   Received RAA with a failed     Clean up     Idle
                 Result-Code
 
       Pending   Received RAA with Result-Code  Update       Open
@@ -5868,32 +5707,33 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Open      Home server wants to           Send ASR     Discon
                 terminate the service
 
-      Open      Authorization-Lifetime (and    Cleanup      Idle
-                Auth-Grace-Period) expires
-                on home server.
 
-      Open      Session-Timeout expires on     Cleanup      Idle
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 105]
+Fajardo, et al.              Standards Track                  [Page 102]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+      Open      Authorization-Lifetime (and    Clean up     Idle
+                Auth-Grace-Period) expires
+                on home server
+
+      Open      Session-Timeout expires on     Clean up     Idle
                 home server
 
       Discon    Failure to send ASR            Wait,        Discon
                                                resend ASR
 
-      Discon    ASR successfully sent and      Cleanup      Idle
+      Discon    ASR successfully sent and      Clean up     Idle
                 ASA Received with Result-Code
 
-      Not       ASA Received                   None         No Change.
+      Not       ASA Received                   None         No Change
       Discon
 
       Any       STR Received                   Send STA,    Idle
-                                               Cleanup.
+                                               Clean up
 
    The following state machine is observed by a client when state is not
    maintained on the server:
@@ -5901,48 +5741,47 @@ Internet-Draft           Diameter Base Protocol             January 2011
                               CLIENT, STATELESS
       State     Event                          Action       New State
       ---------------------------------------------------------------
-      Idle      Client or Device Requests      Send         Pending
-                access                         service
+      Idle      Client or device requests      Send         Pending
+                access                         service-
                                                specific
                                                auth req
 
-      Pending   Successful Service-specific    Grant        Open
-                authorization answer           Access
+      Pending   Successful service-specific    Grant        Open
+                authorization answer           access
                 received with Auth-Session-
                 State set to
                 NO_STATE_MAINTAINED
 
-      Pending   Failed Service-specific        Cleanup      Idle
+      Pending   Failed service-specific        Clean up     Idle
                 authorization answer
                 received
 
-      Open      Session-Timeout Expires on     Discon.      Idle
-                Access Device                  user/device
+      Open      Session-Timeout expires on     Discon.      Idle
+                access device                  user/device
 
       Open      Service to user is terminated  Discon.      Idle
                                                user/device
 
-   The following state machine is observed by a server when it is not
-   maintaining state for the session:
-
-
 
 
 
 
 
-
-Fajardo, et al.           Expires July 24, 2011               [Page 106]
+Fajardo, et al.              Standards Track                  [Page 103]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   The following state machine is observed by a server when it is not
+   maintaining state for the session:
 
                               SERVER, STATELESS
       State     Event                          Action       New State
       ---------------------------------------------------------------
-      Idle      Service-specific authorization Send serv.   Idle
-                request received, and          specific
-                successfully processed         answer
+      Idle      Service-specific authorization Send         Idle
+                request received, and          service-
+                successfully processed         specific
+                                               answer
 
 8.2.  Accounting Session State Machine
 
@@ -5960,8 +5799,8 @@ Internet-Draft           Diameter Base Protocol             January 2011
    machine in this section described below.
 
    The default server side state machine requires the reception of
-   accounting records in any order and at any time, and does not place
-   any standards requirement on the processing of these records.
+   accounting records in any order and at any time, and it does not
+   place any standards requirement on the processing of these records.
    Implementations of Diameter may perform checking, ordering,
    correlation, fraud detection, and other tasks based on these records.
    AVPs may need to be inspected as a part of these tasks.  The tasks
@@ -5970,7 +5809,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    or even policy dependent, they are not standardized by the Diameter
    specifications.  Applications MAY define requirements on when to
    accept accounting records based on the used value of Accounting-
-   Realtime-Required AVP, credit limits checks, and so on.
+   Realtime-Required AVP, credit-limit checks, and so on.
 
    However, the Diameter base protocol defines one optional server side
    state machine that MAY be followed by applications that require
@@ -5978,31 +5817,31 @@ Internet-Draft           Diameter Base Protocol             January 2011
    that such tracking is incompatible with the ability to sustain long
    duration connectivity problems.  Therefore, the use of this state
    machine is recommended only in applications where the value of the
-   Accounting-Realtime-Required AVP is DELIVER_AND_GRANT, and hence
+   Accounting-Realtime-Required AVP is DELIVER_AND_GRANT; hence,
    accounting connectivity problems are required to cause the serviced
    user to be disconnected.  Otherwise, records produced by the client
-   may be lost by the server which no longer accepts them after the
-   connectivity is re-established.  This state machine is the third
-   state machine in this section.  The state machine is supervised by a
-   supervision session timer Ts, which the value should be reasonably
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 107]
+Fajardo, et al.              Standards Track                  [Page 104]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   higher than the Acct_Interim_Interval value.  Ts MAY be set to two
-   times the value of the Acct_Interim_Interval so as to avoid the
-   accounting session in the Diameter server to change to Idle state in
-   case of short transient network failure.
+   may be lost by the server, which no longer accepts them after the
+   connectivity is re-established.  This state machine is the third
+   state machine in this section.  The state machine is supervised by a
+   supervision session timer Ts, whose value should be reasonably higher
+   than the Acct_Interim_Interval value.  Ts MAY be set to two times the
+   value of the Acct_Interim_Interval so as to avoid the accounting
+   session in the Diameter server to change to Idle state in case of
+   short transient network failure.
 
    Any event not listed in the state machines MUST be considered as an
    error condition, and a corresponding answer, if applicable, MUST be
    returned to the originator of the message.
 
-   In the state table, the event 'Failure to send' means that the
+   In the state table, the event "Failure to send" means that the
    Diameter client is unable to communicate with the desired
    destination.  This could be due to the peer being down, or due to the
    peer sending back a transient failure or temporary protocol error
@@ -6010,17 +5849,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
    DIAMETER_LOOP_DETECTED in the Result-Code AVP of the Accounting
    Answer command.
 
-   The event 'Failed answer' means that the Diameter client received a
+   The event "Failed answer" means that the Diameter client received a
    non-transient failure notification in the Accounting Answer command.
 
-   Note that the action 'Disconnect user/dev' MUST have an effect also
-   to the authorization session state table, e.g., cause the STR message
+   Note that the action "Disconnect user/dev" MUST also have an effect
+   on the authorization session state table, e.g., cause the STR message
    to be sent, if the given application has both authentication/
    authorization and accounting portions.
 
-   The states PendingS, PendingI, PendingL, PendingE and PendingB stand
+   The states PendingS, PendingI, PendingL, PendingE, and PendingB stand
    for pending states to wait for an answer to an accounting request
-   related to a Start, Interim, Stop, Event or buffered record,
+   related to a Start, Interim, Stop, Event, or buffered record,
    respectively.
 
                             CLIENT, ACCOUNTING
@@ -6037,36 +5876,36 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Idle      Records in storage             Send         PendingB
                                                record
 
-      PendingS  Successful accounting                       Open
-                start answer received
-
-      PendingS  Failure to send and buffer     Store        Open
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 108]
+Fajardo, et al.              Standards Track                  [Page 105]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-                space available and realtime   Start
+      PendingS  Successful accounting                       Open
+                start answer received
+
+      PendingS  Failure to send and buffer     Store        Open
+                space available and real time  Start
                 not equal to DELIVER_AND_GRANT Record
 
       PendingS  Failure to send and no buffer               Open
-                space available and realtime
+                space available and real time
                 equal to GRANT_AND_LOSE
 
       PendingS  Failure to send and no         Disconnect   Idle
                 buffer space available and     user/dev
-                realtime not equal to
+                real time not equal to
                 GRANT_AND_LOSE
 
       PendingS  Failed accounting start answer              Open
-                received and realtime equal
+                received and real time equal
                 to GRANT_AND_LOSE
 
       PendingS  Failed accounting start answer Disconnect   Idle
-                received and realtime not      user/dev
+                received and real time not     user/dev
                 equal to GRANT_AND_LOSE
 
       PendingS  User service terminated        Store        PendingS
@@ -6077,6 +5916,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
                                                accounting
                                                interim
                                                record
+
       Open      User service terminated        Send         PendingL
                                                accounting
                                                stop req.
@@ -6087,34 +5927,35 @@ Internet-Draft           Diameter Base Protocol             January 2011
       PendingI  Failure to send and (buffer    Store        Open
                 space available or old         interim
                 record can be overwritten)     record
-                and realtime not equal to
+                and real time not equal to
                 DELIVER_AND_GRANT
 
-      PendingI  Failure to send and no buffer               Open
-                space available and realtime
-                equal to GRANT_AND_LOSE
 
 
-      PendingI  Failure to send and no         Disconnect   Idle
-                buffer space available and     user/dev
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 109]
+Fajardo, et al.              Standards Track                  [Page 106]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+      PendingI  Failure to send and no buffer               Open
+                space available and real time
+                equal to GRANT_AND_LOSE
 
-                realtime not equal to
+      PendingI  Failure to send and no         Disconnect   Idle
+                buffer space available and     user/dev
+                real time not equal to
                 GRANT_AND_LOSE
 
       PendingI  Failed accounting interim                   Open
-                answer received and realtime
+                answer received and real time
                 equal to GRANT_AND_LOSE
 
       PendingI  Failed accounting interim      Disconnect   Idle
                 answer received and            user/dev
-                realtime not equal to
+                real time not equal to
                 GRANT_AND_LOSE
 
       PendingI  User service terminated        Store        PendingI
@@ -6148,6 +5989,13 @@ Internet-Draft           Diameter Base Protocol             January 2011
                 space available                stop
                                                record
 
+
+
+Fajardo, et al.              Standards Track                  [Page 107]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
       PendingL  Failure to send and no buffer               Idle
                 space available
 
@@ -6155,124 +6003,133 @@ Internet-Draft           Diameter Base Protocol             January 2011
                 received
 
 
-
-Fajardo, et al.           Expires July 24, 2011               [Page 110]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
                        SERVER, STATELESS ACCOUNTING
       State     Event                          Action       New State
       ---------------------------------------------------------------
 
       Idle      Accounting start request       Send         Idle
-                received, and successfully     accounting
+                received and successfully      accounting
                 processed.                     start
                                                answer
 
       Idle      Accounting event request       Send         Idle
-                received, and successfully     accounting
+                received and successfully      accounting
                 processed.                     event
                                                answer
 
-      Idle      Interim record received,       Send         Idle
+      Idle      Interim record received        Send         Idle
                 and successfully processed.    accounting
                                                interim
                                                answer
 
       Idle      Accounting stop request        Send         Idle
-                received, and successfully     accounting
+                received and successfully      accounting
                 processed                      stop answer
 
-      Idle      Accounting request received,   Send         Idle
+      Idle      Accounting request received;   Send         Idle
                 no space left to store         accounting
-                records                        answer,
+                records                        answer;
                                                Result-Code =
                                                OUT_OF_
                                                SPACE
 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 108]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
                             SERVER, STATEFUL ACCOUNTING
       State     Event                          Action       New State
       ---------------------------------------------------------------
 
       Idle      Accounting start request       Send         Open
-                received, and successfully     accounting
+                received and successfully      accounting
                 processed.                     start
-                                               answer,
+                                               answer;
                                                Start Ts
 
       Idle      Accounting event request       Send         Idle
-                received, and successfully     accounting
+                received and successfully      accounting
                 processed.                     event
                                                answer
-
-      Idle      Accounting request received,   Send         Idle
+      Idle      Accounting request received;   Send         Idle
                 no space left to store         accounting
-                records                        answer,
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 111]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
+                records                        answer;
                                                Result-Code =
                                                OUT_OF_
                                                SPACE
 
-      Open      Interim record received,       Send         Open
+      Open      Interim record received        Send         Open
                 and successfully processed.    accounting
                                                interim
-                                               answer,
+                                               answer;
                                                Restart Ts
 
       Open      Accounting stop request        Send         Idle
-                received, and successfully     accounting
-                processed                      stop answer,
+                received and successfully      accounting
+                processed                      stop answer;
                                                Stop Ts
 
-      Open      Accounting request received,   Send         Idle
+      Open      Accounting request received;   Send         Idle
                 no space left to store         accounting
-                records                        answer,
+                records                        answer;
                                                Result-Code =
                                                OUT_OF_
-                                               SPACE,
+                                               SPACE;
                                                Stop Ts
 
       Open      Session supervision timer Ts   Stop Ts      Idle
                 expired
 
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 109]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 8.3.  Server-Initiated Re-Auth
 
    A Diameter server may initiate a re-authentication and/or re-
    authorization service for a particular session by issuing a Re-Auth-
    Request (RAR).
 
-   For example, for pre-paid services, the Diameter server that
+   For example, for prepaid services, the Diameter server that
    originally authorized a session may need some confirmation that the
    user is still using the services.
 
-   An access device that receives a RAR message with Session-Id equal to
-   a currently active session MUST initiate a re-auth towards the user,
-   if the service supports this particular feature.  Each Diameter
-   application MUST state whether server-initiated re-auth is supported,
-   since some applications do not allow access devices to prompt the
-   user for re-auth.
+   An access device that receives an RAR message with the Session-Id
+   equal to a currently active session MUST initiate a re-auth towards
+   the user, if the service supports this particular feature.  Each
+   Diameter application MUST state whether server-initiated re-auth is
+   supported, since some applications do not allow access devices to
+   prompt the user for re-auth.
 
 8.3.1.  Re-Auth-Request
 
-   The Re-Auth-Request (RAR), indicated by the Command-Code set to 258
+   The Re-Auth-Request (RAR), indicated by the Command Code set to 258
    and the message flags' 'R' bit set, may be sent by any server to the
    access device that is providing session service, to request that the
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 112]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    user be re-authenticated and/or re-authorized.
 
 
@@ -6294,15 +6151,22 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 8.3.2.  Re-Auth-Answer
 
-   The Re-Auth-Answer (RAA), indicated by the Command-Code set to 258
+   The Re-Auth-Answer (RAA), indicated by the Command Code set to 258
    and the message flags' 'R' bit clear, is sent in response to the RAR.
-   The Result-Code AVP MUST be present, and indicates the disposition of
-   the request.
+   The Result-Code AVP MUST be present, and it indicates the disposition
+   of the request.
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 110]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
    A successful RAA message MUST be followed by an application-specific
    authentication and/or authorization message.
 
-
     Message Format
 
          <RAA>  ::= < Diameter Header: 258, PXY >
@@ -6321,14 +6185,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
                   * [ Proxy-Info ]
                   * [ AVP ]
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 113]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 8.4.  Session Termination
 
    It is necessary for a Diameter server that authorized a session, for
@@ -6356,6 +6212,14 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    It is also possible that a session that was authorized is never
    actually started due to action of a proxy.  For example, a proxy may
+
+
+
+Fajardo, et al.              Standards Track                  [Page 111]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    modify an authorization answer, converting the result from success to
    failure, prior to forwarding the message to the access device.  If
    the answer did not contain an Auth-Session-State AVP with the value
@@ -6366,36 +6230,27 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    A Diameter server that receives an STR message MUST clean up
    resources (e.g., session state) associated with the Session-Id
-   specified in the STR, and return a Session-Termination-Answer.
+   specified in the STR and return a Session-Termination-Answer.
 
    A Diameter server also MUST clean up resources when the Session-
    Timeout expires, or when the Authorization-Lifetime and the Auth-
-   Grace-Period AVPs expires without receipt of a re-authorization
+   Grace-Period AVPs expire without receipt of a re-authorization
    request, regardless of whether an STR for that session is received.
    The access device is not expected to provide service beyond the
    expiration of these timers; thus, expiration of either of these
    timers implies that the access device may have unexpectedly shut
    down.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 114]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 8.4.1.  Session-Termination-Request
 
-   The Session-Termination-Request (STR), indicated by the Command-Code
+   The Session-Termination-Request (STR), indicated by the Command Code
    set to 275 and the Command Flags' 'R' bit set, is sent by a Diameter
-   client or by a Diameter proxy to inform the Diameter Server that an
+   client or by a Diameter proxy to inform the Diameter server that an
    authenticated and/or authorized session is being terminated.
 
+    Message Format
 
-                   Message Format
-
-         <STR> ::= < Diameter Header: 275, REQ, PXY >
+        <STR>  ::= < Diameter Header: 275, REQ, PXY >
                    < Session-Id >
                    { Origin-Host }
                    { Origin-Realm }
@@ -6410,40 +6265,33 @@ Internet-Draft           Diameter Base Protocol             January 2011
                  * [ Route-Record ]
                  * [ AVP ]
 
-8.4.2.  Session-Termination-Answer
-
-   The Session-Termination-Answer (STA), indicated by the Command-Code
-   set to 275 and the message flags' 'R' bit clear, is sent by the
-   Diameter Server to acknowledge the notification that the session has
-   been terminated.  The Result-Code AVP MUST be present, and MAY
-   contain an indication that an error occurred while servicing the STR.
-
-   Upon sending or receipt of the STA, the Diameter Server MUST release
-   all resources for the session indicated by the Session-Id AVP.  Any
-   intermediate server in the Proxy-Chain MAY also release any
-   resources, if necessary.
-
-
-
-
-
 
 
 
 
 
 
+Fajardo, et al.              Standards Track                  [Page 112]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+8.4.2.  Session-Termination-Answer
 
-Fajardo, et al.           Expires July 24, 2011               [Page 115]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   The Session-Termination-Answer (STA), indicated by the Command Code
+   set to 275 and the message flags' 'R' bit clear, is sent by the
+   Diameter server to acknowledge the notification that the session has
+   been terminated.  The Result-Code AVP MUST be present, and it MAY
+   contain an indication that an error occurred while servicing the STR.
 
+   Upon sending or receipt of the STA, the Diameter server MUST release
+   all resources for the session indicated by the Session-Id AVP.  Any
+   intermediate server in the Proxy-Chain MAY also release any
+   resources, if necessary.
 
-                    Message Format
+    Message Format
 
-         <STA>  ::= < Diameter Header: 275, PXY >
+         <STA> ::= < Diameter Header: 275, PXY >
                     < Session-Id >
                     { Result-Code }
                     { Origin-Host }
@@ -6473,31 +6321,29 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    An access device that receives an ASR with Session-ID equal to a
    currently active session MAY stop the session.  Whether the access
-   device stops the session or not is implementation- and/or
-   configuration-dependent.  For example, an access device may honor
+   device stops the session or not is implementation and/or
+   configuration dependent.  For example, an access device may honor
    ASRs from certain agents only.  In any case, the access device MUST
+
+
+
+Fajardo, et al.              Standards Track                  [Page 113]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    respond with an Abort-Session-Answer, including a Result-Code AVP to
    indicate what action it took.
 
 8.5.1.  Abort-Session-Request
 
-   The Abort-Session-Request (ASR), indicated by the Command-Code set to
+   The Abort-Session-Request (ASR), indicated by the Command Code set to
    274 and the message flags' 'R' bit set, may be sent by any Diameter
    server or any Diameter proxy to the access device that is providing
    session service, to request that the session identified by the
    Session-Id be stopped.
 
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 116]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-                    Message Format
+    Message Format
 
          <ASR>  ::= < Diameter Header: 274, REQ, PXY >
                     < Session-Id >
@@ -6514,20 +6360,35 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 8.5.2.  Abort-Session-Answer
 
-   The Abort-Session-Answer (ASA), indicated by the Command-Code set to
+   The Abort-Session-Answer (ASA), indicated by the Command Code set to
    274 and the message flags' 'R' bit clear, is sent in response to the
-   ASR.  The Result-Code AVP MUST be present, and indicates the
+   ASR.  The Result-Code AVP MUST be present and indicates the
    disposition of the request.
 
    If the session identified by Session-Id in the ASR was successfully
-   terminated, Result-Code is set to DIAMETER_SUCCESS.  If the session
-   is not currently active, Result-Code is set to
+   terminated, the Result-Code is set to DIAMETER_SUCCESS.  If the
+   session is not currently active, the Result-Code is set to
    DIAMETER_UNKNOWN_SESSION_ID.  If the access device does not stop the
-   session for any other reason, Result-Code is set to
+   session for any other reason, the Result-Code is set to
    DIAMETER_UNABLE_TO_COMPLY.
 
 
-                    Message Format
+
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 114]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+    Message Format
 
          <ASA>  ::= < Diameter Header: 274, PXY >
                     < Session-Id >
@@ -6545,14 +6406,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
                   * [ Proxy-Info ]
                   * [ AVP ]
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 117]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 8.6.  Inferring Session Termination from Origin-State-Id
 
    The Origin-State-Id is used to allow detection of terminated sessions
@@ -6560,94 +6413,96 @@ Internet-Draft           Diameter Base Protocol             January 2011
    shutdown of an access device.
 
    A Diameter client or access device increments the value of the
-   Origin-State-Id every time it is started or powered-up.  The new
+   Origin-State-Id every time it is started or powered up.  The new
    Origin-State-Id is then sent in the CER/CEA message immediately upon
    connection to the server.  The Diameter server receiving the new
    Origin-State-Id can determine whether the sending Diameter client had
-   abruptly shutdown by comparing the old value of the Origin-State-Id
+   abruptly shut down by comparing the old value of the Origin-State-Id
    it has kept for that specific client is less than the new value and
    whether it has un-terminated sessions originating from that client.
 
    An access device can also include the Origin-State-Id in request
-   messages other than CER if there are relays or proxies in between the
-   access device and the server.  In this case, however, the server
+   messages other than the CER if there are relays or proxies in between
+   the access device and the server.  In this case, however, the server
    cannot discover that the access device has been restarted unless and
-   until it receives a new request from it.  Therefore this mechanism is
-   more opportunistic across proxies and relays.
+   until it receives a new request from it.  Therefore, this mechanism
+   is more opportunistic across proxies and relays.
 
    The Diameter server may assume that all sessions that were active
    prior to detection of a client restart have been terminated.  The
    Diameter server MAY clean up all session state associated with such
-   lost sessions, and MAY also issues STRs for all such lost sessions
+   lost sessions, and it MAY also issue STRs for all such lost sessions
    that were authorized on upstream servers, to allow session state to
    be cleaned up globally.
 
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 115]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
 8.7.  Auth-Request-Type AVP
 
    The Auth-Request-Type AVP (AVP Code 274) is of type Enumerated and is
    included in application-specific auth requests to inform the peers
-   whether a user is to be authenticated only, authorized only or both.
+   whether a user is to be authenticated only, authorized only, or both.
    Note any value other than both MAY cause RADIUS interoperability
    issues.  The following values are defined:
 
-
    AUTHENTICATE_ONLY 1
 
-      The request being sent is for authentication only, and MUST
-      contain the relevant application specific authentication AVPs that
+      The request being sent is for authentication only, and it MUST
+      contain the relevant application-specific authentication AVPs that
       are needed by the Diameter server to authenticate the user.
 
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 118]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    AUTHORIZE_ONLY 2
 
-      The request being sent is for authorization only, and MUST contain
-      the application-specific authorization AVPs that are necessary to
-      identify the service being requested/offered.
-
+      The request being sent is for authorization only, and it MUST
+      contain the application-specific authorization AVPs that are
+      necessary to identify the service being requested/offered.
 
    AUTHORIZE_AUTHENTICATE 3
 
       The request contains a request for both authentication and
       authorization.  The request MUST include both the relevant
-      application-specific authentication information, and authorization
+      application-specific authentication information and authorization
       information necessary to identify the service being requested/
       offered.
 
-
 8.8.  Session-Id AVP
 
    The Session-Id AVP (AVP Code 263) is of type UTF8String and is used
    to identify a specific session (see Section 8).  All messages
-   pertaining to a specific session MUST include only one Session-Id AVP
-   and the same value MUST be used throughout the life of a session.
-   When present, the Session-Id SHOULD appear immediately following the
-   Diameter Header (see Section 3).
+   pertaining to a specific session MUST include only one Session-Id
+   AVP, and the same value MUST be used throughout the life of a
+   session.  When present, the Session-Id SHOULD appear immediately
+   following the Diameter header (see Section 3).
 
    The Session-Id MUST be globally and eternally unique, as it is meant
    to uniquely identify a user session without reference to any other
-   information, and may be needed to correlate historical authentication
-   information with accounting information.  The Session-Id includes a
-   mandatory portion and an implementation-defined portion; a
-   recommended format for the implementation-defined portion is outlined
-   below.
+   information, and it may be needed to correlate historical
+   authentication information with accounting information.  The
+   Session-Id includes a mandatory portion and an implementation-defined
+   portion; a recommended format for the implementation-defined portion
+   is outlined below.
 
    The Session-Id MUST begin with the sender's identity encoded in the
-   DiameterIdentity type (see Section 4.4).  The remainder of the
-   Session-Id is delimited by a ";" character, and MAY be any sequence
-   that the client can guarantee to be eternally unique; however, the
-   following format is recommended, (square brackets [] indicate an
-   optional element):
+   DiameterIdentity type (see Section 4.3.1).  The remainder of the
+   Session-Id is delimited by a ";" character, and it MAY be any
+
+
+
+Fajardo, et al.              Standards Track                  [Page 116]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   sequence that the client can guarantee to be eternally unique;
+   however, the following format is recommended, (square brackets []
+   indicate an optional element):
 
       <DiameterIdentity>;<high 32 bits>;<low 32 bits>[;<optional value>]
 
@@ -6657,22 +6512,14 @@ Internet-Draft           Diameter Base Protocol             January 2011
    processors.  At startup, the high 32 bits of the 64-bit value MAY be
    initialized to the time in NTP format [RFC5905], and the low 32 bits
    MAY be initialized to zero.  This will for practical purposes
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 119]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    eliminate the possibility of overlapping Session-Ids after a reboot,
    assuming the reboot process takes longer than a second.
    Alternatively, an implementation MAY keep track of the increasing
    value in non-volatile memory.
 
 
-   <optional value> is implementation specific but may include a modem's
-   device Id, a layer 2 address, timestamp, etc.
+   <optional value> is implementation specific, but it may include a
+   modem's device Id, a Layer 2 address, timestamp, etc.
 
    Example, in which there is no optional value:
 
@@ -6683,45 +6530,44 @@ Internet-Draft           Diameter Base Protocol             January 2011
      accesspoint7.example.com;1876543210;523;[email protected]
 
    The Session-Id is created by the Diameter application initiating the
-   session, which in most cases is done by the client.  Note that a
-   Session-Id MAY be used for both the authentication, authorization and
-   accounting commands of a given application.
+   session, which, in most cases, is done by the client.  Note that a
+   Session-Id MAY be used for both the authentication, authorization,
+   and accounting commands of a given application.
 
 8.9.  Authorization-Lifetime AVP
 
    The Authorization-Lifetime AVP (AVP Code 291) is of type Unsigned32
    and contains the maximum number of seconds of service to be provided
    to the user before the user is to be re-authenticated and/or re-
-   authorized.  Care should be taken when the Authorization- Lifetime
-   value is determined, since a low, non-zero, value could create
+   authorized.  Care should be taken when the Authorization-Lifetime
+   value is determined, since a low, non-zero value could create
    significant Diameter traffic, which could congest both the network
    and the agents.
 
    A value of zero (0) means that immediate re-auth is necessary by the
    access device.  The absence of this AVP, or a value of all ones
-   (meaning all bits in the 32 bit field are set to one) means no re-
+   (meaning all bits in the 32-bit field are set to one) means no re-
    auth is expected.
 
+
+
+Fajardo, et al.              Standards Track                  [Page 117]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    If both this AVP and the Session-Timeout AVP are present in a
    message, the value of the latter MUST NOT be smaller than the
    Authorization-Lifetime AVP.
 
    An Authorization-Lifetime AVP MAY be present in re-authorization
-   messages, and contains the number of seconds the user is authorized
-   to receive service from the time the re-auth answer message is
-   received by the access device.
+   messages, and it contains the number of seconds the user is
+   authorized to receive service from the time the re-auth answer
+   message is received by the access device.
 
    This AVP MAY be provided by the client as a hint of the maximum
    lifetime that it is willing to accept.  The server MUST return a
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 120]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-   value that is equal to, or smaller, than the one provided by the
+   value that is equal to, or smaller than, the one provided by the
    client.
 
 8.10.  Auth-Grace-Period AVP
@@ -6739,7 +6585,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
    the value in the server's answer message is binding.  The following
    values are supported:
 
-
    STATE_MAINTAINED 0
 
       This value is used to specify that session state is being
@@ -6747,46 +6592,42 @@ Internet-Draft           Diameter Base Protocol             January 2011
       message when service to the user is terminated.  This is the
       default value.
 
-
    NO_STATE_MAINTAINED 1
 
       This value is used to specify that no session termination messages
       will be sent by the access device upon expiration of the
       Authorization-Lifetime.
 
-
 8.12.  Re-Auth-Request-Type AVP
 
    The Re-Auth-Request-Type AVP (AVP Code 285) is of type Enumerated and
    is included in application-specific auth answers to inform the client
    of the action expected upon expiration of the Authorization-Lifetime.
-   If the answer message contains an Authorization-Lifetime AVP with a
-   positive value, the Re-Auth-Request-Type AVP MUST be present in an
-   answer message.  The following values are defined:
 
 
-   AUTHORIZE_ONLY 0
 
-      An authorization only re-auth is expected upon expiration of the
-      Authorization-Lifetime.  This is the default value if the AVP is
 
+Fajardo, et al.              Standards Track                  [Page 118]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 121]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   If the answer message contains an Authorization-Lifetime AVP with a
+   positive value, the Re-Auth-Request-Type AVP MUST be present in an
+   answer message.  The following values are defined:
 
+   AUTHORIZE_ONLY 0
 
+      An authorization only re-auth is expected upon expiration of the
+      Authorization-Lifetime.  This is the default value if the AVP is
       not present in answer messages that include the Authorization-
       Lifetime.
 
-
    AUTHORIZE_AUTHENTICATE 1
 
       An authentication and authorization re-auth is expected upon
       expiration of the Authorization-Lifetime.
 
-
 8.13.  Session-Timeout AVP
 
    The Session-Timeout AVP (AVP Code 27) [RFC2865] is of type Unsigned32
@@ -6799,10 +6640,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
    A session that terminates on an access device due to the expiration
    of the Session-Timeout MUST cause an STR to be issued, unless both
    the access device and the home server had previously agreed that no
-   session termination messages would be sent (see Section 8.11).
+   session termination messages would be sent (see Section 8).
 
    A Session-Timeout AVP MAY be present in a re-authorization answer
-   message, and contains the remaining number of seconds from the
+   message, and it contains the remaining number of seconds from the
    beginning of the re-auth.
 
    A value of zero, or the absence of this AVP, means that this session
@@ -6810,7 +6651,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    This AVP MAY be provided by the client as a hint of the maximum
    timeout that it is willing to accept.  However, the server MAY return
-   a value that is equal to, or smaller, than the one provided by the
+   a value that is equal to, or smaller than, the one provided by the
    client.
 
 8.14.  User-Name AVP
@@ -6819,83 +6660,29 @@ Internet-Draft           Diameter Base Protocol             January 2011
    contains the User-Name, in a format consistent with the NAI
    specification [RFC4282].
 
-8.15.  Termination-Cause AVP
-
-   The Termination-Cause AVP (AVP Code 295) is of type Enumerated, and
-   is used to indicate the reason why a session was terminated on the
-   access device.  The following values are defined:
-
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 122]
+Fajardo, et al.              Standards Track                  [Page 119]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-   DIAMETER_LOGOUT 1
-
-      The user initiated a disconnect
-
-
-   DIAMETER_SERVICE_NOT_PROVIDED 2
-
-      This value is used when the user disconnected prior to the receipt
-      of the authorization answer message.
-
-
-   DIAMETER_BAD_ANSWER 3
-
-      This value indicates that the authorization answer received by the
-      access device was not processed successfully.
-
-
-    DIAMETER_ADMINISTRATIVE 4
-
-      The user was not granted access, or was disconnected, due to
-      administrative reasons, such as the receipt of a Abort-Session-
-      Request message.
-
-
-    DIAMETER_LINK_BROKEN 5
-
-      The communication to the user was abruptly disconnected.
-
-
-    DIAMETER_AUTH_EXPIRED 6
-
-      The user's access was terminated since its authorized session time
-      has expired.
-
-
-    DIAMETER_USER_MOVED 7
-
-      The user is receiving services from another access device.
-
-
-    DIAMETER_SESSION_TIMEOUT 8
+RFC 6733                 Diameter Base Protocol             October 2012
 
-      The user's session has timed out, and service has been terminated.
 
+8.15.  Termination-Cause AVP
 
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 123]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+   The Termination-Cause AVP (AVP Code 295) is of type Enumerated, and
+   is used to indicate the reason why a session was terminated on the
+   access device.  The currently assigned values for this AVP can be
+   found in the IANA registry for Termination-Cause AVP Values
+   [IANATCV].
 
 8.16.  Origin-State-Id AVP
 
    The Origin-State-Id AVP (AVP Code 278), of type Unsigned32, is a
    monotonically increasing value that is advanced whenever a Diameter
-   entity restarts with loss of previous state, for example upon reboot.
-   Origin-State-Id MAY be included in any Diameter message, including
-   CER.
+   entity restarts with loss of previous state, for example, upon
+   reboot.  Origin-State-Id MAY be included in any Diameter message,
+   including CER.
 
    A Diameter entity issuing this AVP MUST create a higher value for
    this AVP each time its state is reset.  A Diameter entity MAY set
@@ -6911,20 +6698,34 @@ Internet-Draft           Diameter Base Protocol             January 2011
    message, it allows other Diameter entities to infer that sessions
    associated with a lower Origin-State-Id are no longer active.  If an
    access device does not intend for such inferences to be made, it MUST
-   either not include Origin-State-Id in any message, or set its value
-   to 0.
+   either not include Origin-State-Id in any message or set its value to
+   0.
 
 8.17.  Session-Binding AVP
 
-   The Session-Binding AVP (AVP Code 270) is of type Unsigned32, and MAY
-   be present in application-specific authorization answer messages.  If
-   present, this AVP MAY inform the Diameter client that all future
+   The Session-Binding AVP (AVP Code 270) is of type Unsigned32, and it
+   MAY be present in application-specific authorization answer messages.
+   If present, this AVP MAY inform the Diameter client that all future
    application-specific re-auth and Session-Termination-Request messages
    for this session MUST be sent to the same authorization server.
 
-   This field is a bit mask, and the following bits have been defined:
 
 
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 120]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   This field is a bit mask, and the following bits have been defined:
+
    RE_AUTH 1
 
       When set, future re-auth messages for this session MUST NOT
@@ -6932,23 +6733,13 @@ Internet-Draft           Diameter Base Protocol             January 2011
       value, the Destination-Host AVP MUST be present in all re-auth
       messages for this session.
 
-
    STR 2
 
       When set, the STR message for this session MUST NOT include the
       Destination-Host AVP.  When cleared, the default value, the
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 124]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       Destination-Host AVP MUST be present in the STR message for this
       session.
 
-
    ACCOUNTING 4
 
       When set, all accounting messages for this session MUST NOT
@@ -6956,10 +6747,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
       value, the Destination-Host AVP, if known, MUST be present in all
       accounting messages for this session.
 
-
 8.18.  Session-Server-Failover AVP
 
-   The Session-Server-Failover AVP (AVP Code 271) is of type Enumerated,
+   The Session-Server-Failover AVP (AVP Code 271) is of type Enumerated
    and MAY be present in application-specific authorization answer
    messages that either do not include the Session-Binding AVP or
    include the Session-Binding AVP with any of the bits set to a zero
@@ -6970,11 +6760,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    The following values are supported:
 
-
    REFUSE_SERVICE 0
 
       If either the re-auth or the STR message delivery fails, terminate
-      service with the user, and do not attempt any subsequent attempts.
+      service with the user and do not attempt any subsequent attempts.
+
+
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 121]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    TRY_AGAIN 1
@@ -6982,34 +6785,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
       If either the re-auth or the STR message delivery fails, resend
       the failed message without the Destination-Host AVP present.
 
-
    ALLOW_SERVICE 2
 
       If re-auth message delivery fails, assume that re-authorization
       succeeded.  If STR message delivery fails, terminate the session.
 
-
    TRY_AGAIN_ALLOW_SERVICE 3
 
       If either the re-auth or the STR message delivery fails, resend
       the failed message without the Destination-Host AVP present.  If
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 125]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
       the second delivery fails for re-auth, assume re-authorization
       succeeded.  If the second delivery fails for STR, terminate the
       session.
 
-
 8.19.  Multi-Round-Time-Out AVP
 
-   The Multi-Round-Time-Out AVP (AVP Code 272) is of type Unsigned32,
-   and SHOULD be present in application-specific authorization answer
+   The Multi-Round-Time-Out AVP (AVP Code 272) is of type Unsigned32 and
+   SHOULD be present in application-specific authorization answer
    messages whose Result-Code AVP is set to DIAMETER_MULTI_ROUND_AUTH.
    This AVP contains the maximum number of seconds that the access
    device MUST provide the user in responding to an authentication
@@ -7031,37 +6823,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 8.21.  Event-Timestamp AVP
 
-   The Event-Timestamp (AVP Code 55) is of type Time, and MAY be
-   included in an Accounting-Request and Accounting-Answer messages to
-   record the time that the reported event occurred, in seconds since
-   January 1, 1900 00:00 UTC.
-
-
+   The Event-Timestamp (AVP Code 55) is of type Time and MAY be included
+   in an Accounting-Request and Accounting-Answer messages to record the
+   time that the reported event occurred, in seconds since January 1,
+   1900 00:00 UTC.
 
 
 
 
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 126]
+Fajardo, et al.              Standards Track                  [Page 122]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 9.  Accounting
 
    This accounting protocol is based on a server directed model with
    capabilities for real-time delivery of accounting information.
-   Several fault resilience methods [RFC2975] have been built in to the
+   Several fault resilience methods [RFC2975] have been built into the
    protocol in order minimize loss of accounting data in various fault
    situations and under different assumptions about the capabilities of
    the used devices.
@@ -7075,15 +6854,16 @@ Internet-Draft           Diameter Base Protocol             January 2011
    timeliness requirements.
 
    As discussed in [RFC2975], real-time transfer of accounting records
-   is a requirement, such as the need to perform credit limit checks and
+   is a requirement, such as the need to perform credit-limit checks and
    fraud detection.  Note that batch accounting is not a requirement,
    and is therefore not supported by Diameter.  Should batched
    accounting be required in the future, a new Diameter application will
    need to be created, or it could be handled using another protocol.
-   Note, however, that even if at the Diameter layer accounting requests
-   are processed one by one, transport protocols used under Diameter
-   typically batch several requests in the same packet under heavy
-   traffic conditions.  This may be sufficient for many applications.
+   Note, however, that even if at the Diameter layer, accounting
+   requests are processed one by one; transport protocols used under
+   Diameter typically batch several requests in the same packet under
+   heavy traffic conditions.  This may be sufficient for many
+   applications.
 
    The authorization server (chain) directs the selection of proper
    transfer strategy, based on its knowledge of the user and
@@ -7097,7 +6877,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
    records from the Diameter client is delayed or unsuccessful.
 
    The Diameter accounting server MAY override the interim interval or
-   the realtime requirements by including the Acct-Interim-Interval or
+   the real-time requirements by including the Acct-Interim-Interval or
    Accounting-Realtime-Required AVP in the Accounting-Answer message.
    When one of these AVPs is present, the latest value received SHOULD
    be used in further accounting activities for the same session.
@@ -7107,16 +6887,15 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-
-Fajardo, et al.           Expires July 24, 2011               [Page 127]
+Fajardo, et al.              Standards Track                  [Page 123]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 9.2.  Protocol Messages
 
    A Diameter node that receives a successful authentication and/or
-   authorization messages from the Diameter server SHOULD collect
+   authorization message from the Diameter server SHOULD collect
    accounting information for the session.  The Accounting-Request
    message is used to transmit the accounting information to the
    Diameter server, which MUST reply with the Accounting-Answer message
@@ -7129,12 +6908,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 9.3.  Accounting Application Extension and Requirements
 
-   Each Diameter application (e.g., NASREQ, MobileIP), SHOULD define
-   their Service-Specific AVPs that MUST be present in the Accounting-
-   Request message in a section entitled "Accounting AVPs".  The
-   application MUST assume that the AVPs described in this document will
-   be present in all Accounting messages, so only their respective
-   service-specific AVPs need to be defined in that section.
+   Each Diameter application (e.g., NASREQ, Mobile IP) SHOULD define its
+   service-specific AVPs that MUST be present in the Accounting-Request
+   message in a section titled "Accounting AVPs".  The application MUST
+   assume that the AVPs described in this document will be present in
+   all Accounting messages, so only their respective service-specific
+   AVPs need to be defined in that section.
 
    Applications have the option of using one or both of the following
    accounting application extension models:
@@ -7150,40 +6929,37 @@ Internet-Draft           Diameter Base Protocol             January 2011
       advertise the Diameter base accounting Application Id during
       capabilities exchange.
 
-
    Coupled Accounting Service
 
-      The accounting messages will carry the Application Id of the
+      The accounting message will carry the Application Id of the
       application that is using it.  The application itself will process
       the received accounting records or forward them to an accounting
       server.  There is no accounting application advertisement required
-      during capabilities exchange and the accounting messages will be
-      routed the same as any of the other application messages.
-
+      during capabilities exchange, and the accounting messages will be
+      routed the same way as any of the other application messages.
 
+   In cases where an application does not define its own accounting
+   service, it is preferred that the split accounting model be used.
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 128]
+Fajardo, et al.              Standards Track                  [Page 124]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-      In cases where an application does not define its own accounting
-      service, it is preferred that the split accounting model be used.
-
 9.4.  Fault Resilience
 
-   Diameter Base protocol mechanisms are used to overcome small message
-   loss and network faults of temporary nature.
+   Diameter base protocol mechanisms are used to overcome small message
+   loss and network faults of a temporary nature.
 
    Diameter peers acting as clients MUST implement the use of failover
    to guard against server failures and certain network failures.
    Diameter peers acting as agents or related off-line processing
    systems MUST detect duplicate accounting records caused by the
-   sending of same record to several servers and duplication of messages
-   in transit.  This detection MUST be based on the inspection of the
-   Session-Id and Accounting-Record-Number AVP pairs.  Appendix C
+   sending of the same record to several servers and duplication of
+   messages in transit.  This detection MUST be based on the inspection
+   of the Session-Id and Accounting-Record-Number AVP pairs.  Appendix C
    discusses duplicate detection needs and implementation issues.
 
    Diameter clients MAY have non-volatile memory for the safe storage of
@@ -7191,23 +6967,23 @@ Internet-Draft           Diameter Base Protocol             January 2011
    partitions, and server failures.  If such memory is available, the
    client SHOULD store new accounting records there as soon as the
    records are created and until a positive acknowledgement of their
-   reception from the Diameter Server has been received.  Upon a reboot,
-   the client MUST starting sending the records in the non-volatile
-   memory to the accounting server with appropriate modifications in
+   reception from the Diameter server has been received.  Upon a reboot,
+   the client MUST start sending the records in the non-volatile memory
+   to the accounting server with the appropriate modifications in
    termination cause, session length, and other relevant information in
    the records.
 
    A further application of this protocol may include AVPs to control
-   how many accounting records may at most be stored in the Diameter
-   client without committing them to the non-volatile memory or
+   the maximum number of accounting records that may be stored in the
+   Diameter client without committing them to the non-volatile memory or
    transferring them to the Diameter server.
 
    The client SHOULD NOT remove the accounting data from any of its
    memory areas before the correct Accounting-Answer has been received.
-   The client MAY remove oldest, undelivered or yet unacknowledged
-   accounting data if it runs out of resources such as memory.  It is an
-   implementation dependent matter for the client to accept new sessions
-   under this condition.
+   The client MAY remove the oldest, undelivered, or as yet
+   unacknowledged accounting data if it runs out of resources such as
+   memory.  It is an implementation-dependent matter for the client to
+   accept new sessions under this condition.
 
 9.5.  Accounting Records
 
@@ -7217,15 +6993,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    Different types of accounting records are sent depending on the
    actual type of accounted service and the authorization server's
+   directions for interim accounting.  If the accounted service is a
+
+
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 129]
+Fajardo, et al.              Standards Track                  [Page 125]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   directions for interim accounting.  If the accounted service is a
    one-time event, meaning that the start and stop of the event are
    simultaneous, then the Accounting-Record-Type AVP MUST be present and
    set to the value EVENT_RECORD.
@@ -7251,11 +7029,11 @@ Internet-Draft           Diameter Base Protocol             January 2011
    session.
 
    A particular value of Accounting-Sub-Session-Id MUST appear only in
-   one sequence of accounting records from a DIAMETER client, except for
+   one sequence of accounting records from a Diameter client, except for
    the purposes of retransmission.  The one sequence that is sent MUST
    be either one record with Accounting-Record-Type AVP set to the value
-   EVENT_RECORD, or several records starting with one having the value
-   START_RECORD, followed by zero or more INTERIM_RECORD and a single
+   EVENT_RECORD or several records starting with one having the value
+   START_RECORD, followed by zero or more INTERIM_RECORDs and a single
    STOP_RECORD.  A particular Diameter application specification MUST
    define the type of sequences that MUST be used.
 
@@ -7265,20 +7043,21 @@ Internet-Draft           Diameter Base Protocol             January 2011
    accounting records with a specific application session by using the
    Session-Id of the particular application session in the accounting
    messages.  Accounting messages MAY also use a different Session-Id
-   from that of the application sessions in which case other session
+   from that of the application sessions, in which case, other session-
    related information is needed to perform correlation.
 
    In cases where an application requires multiple accounting sub-
-   session, an Accounting-Sub-Session-Id AVP is used to differentiate
+   sessions, an Accounting-Sub-Session-Id AVP is used to differentiate
    each sub-session.  The Session-Id would remain constant for all sub-
-   sessions and is be used to correlate all the sub-sessions to a
+   sessions and is used to correlate all the sub-sessions to a
    particular application session.  Note that receiving a STOP_RECORD
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 130]
+
+Fajardo, et al.              Standards Track                  [Page 126]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    with no Accounting-Sub-Session-Id AVP when sub-sessions were
@@ -7290,36 +7069,36 @@ Internet-Draft           Diameter Base Protocol             January 2011
    record may span multiple different Diameter applications and sessions
    used by the same user at a given time.  In such cases, the Acct-
    Multi-Session-Id AVP is used.  The Acct-Multi-Session-Id AVP SHOULD
-   be signaled by the server to the access device (typically during
+   be signaled by the server to the access device (typically, during
    authorization) when it determines that a request belongs to an
    existing session.  The access device MUST then include the Acct-
    Multi-Session-Id AVP in all subsequent accounting messages.
 
    The Acct-Multi-Session-Id AVP MAY include the value of the original
-   Session-Id.  It's contents are implementation specific, but MUST be
-   globally unique across other Acct-Multi-Session-Id, and MUST NOT
+   Session-Id.  Its contents are implementation specific, but the MUST
+   be globally unique across other Acct-Multi-Session-Ids and MUST NOT
    change during the life of a session.
 
    A Diameter application document MUST define the exact concept of a
-   session that is being accounted, and MAY define the concept of a
+   session that is being accounted, and it MAY define the concept of a
    multi-session.  For instance, the NASREQ DIAMETER application treats
-   a single PPP connection to a Network Access Server as one session,
-   and a set of Multilink PPP sessions as one multi-session.
+   a single PPP connection to a Network Access Server as one session and
+   a set of Multilink PPP sessions as one multi-session.
 
-9.7.  Accounting Command-Codes
+9.7.  Accounting Command Codes
 
-   This section defines Command-Code values that MUST be supported by
-   all Diameter implementations that provide Accounting services.
+   This section defines Command Code values that MUST be supported by
+   all Diameter implementations that provide accounting services.
 
 9.7.1.  Accounting-Request
 
-   The Accounting-Request (ACR) command, indicated by the Command-Code
+   The Accounting-Request (ACR) command, indicated by the Command Code
    field set to 271 and the Command Flags' 'R' bit set, is sent by a
    Diameter node, acting as a client, in order to exchange accounting
    information with a peer.
 
-   The AVP listed below SHOULD include service-specific accounting AVPs,
-   as described in Section 9.3.
+   In addition to the AVPs listed below, Accounting-Request messages
+   SHOULD include service-specific accounting AVPs.
 
 
 
@@ -7332,9 +7111,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 131]
+Fajardo, et al.              Standards Track                  [Page 127]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
       Message Format
@@ -7363,16 +7142,16 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 9.7.2.  Accounting-Answer
 
-   The Accounting-Answer (ACA) command, indicated by the Command-Code
+   The Accounting-Answer (ACA) command, indicated by the Command Code
    field set to 271 and the Command Flags' 'R' bit cleared, is used to
    acknowledge an Accounting-Request command.  The Accounting-Answer
    command contains the same Session-Id as the corresponding request.
 
-   Only the target Diameter Server, known as the home Diameter Server,
+   Only the target Diameter server, known as the home Diameter server,
    SHOULD respond with the Accounting-Answer command.
 
-   The AVP listed below SHOULD include service-specific accounting AVPs,
-   as described in Section 9.3.
+   In addition to the AVPs listed below, Accounting-Answer messages
+   SHOULD include service-specific accounting AVPs.
 
 
 
@@ -7388,9 +7167,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 132]
+Fajardo, et al.              Standards Track                  [Page 128]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
       Message Format
@@ -7429,13 +7208,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
    and contains the type of accounting record being sent.  The following
    values are currently defined for the Accounting-Record-Type AVP:
 
-
    EVENT_RECORD 1
 
       An Accounting Event Record is used to indicate that a one-time
       event has occurred (meaning that the start and end of the event
       are simultaneous).  This record contains all information relevant
-      to the service, and is the only record of the service.
+      to the service, and it is the only record of the service.
 
 
 
@@ -7444,20 +7222,20 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 133]
+
+Fajardo, et al.              Standards Track                  [Page 129]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
    START_RECORD 2
 
-      An Accounting Start, Interim, and Stop Records are used to
-      indicate that a service of a measurable length has been given.  An
-      Accounting Start Record is used to initiate an accounting session,
+      Accounting Start, Interim, and Stop Records are used to indicate
+      that a service of a measurable length has been given.  An
+      Accounting Start Record is used to initiate an accounting session
       and contains accounting information that is relevant to the
       initiation of the session.
 
-
    INTERIM_RECORD 3
 
       An Interim Accounting Record contains cumulative accounting
@@ -7468,14 +7246,12 @@ Internet-Draft           Diameter Base Protocol             January 2011
       applications.  The selection of whether to use INTERIM_RECORD
       records is done by the Acct-Interim-Interval AVP.
 
-
    STOP_RECORD 4
 
       An Accounting Stop Record is sent to terminate an accounting
       session and contains cumulative accounting information relevant to
       the existing session.
 
-
 9.8.2.  Acct-Interim-Interval AVP
 
    The Acct-Interim-Interval AVP (AVP Code 85) is of type Unsigned32 and
@@ -7483,31 +7259,31 @@ Internet-Draft           Diameter Base Protocol             January 2011
    client.  The client uses information in this AVP to decide how and
    when to produce accounting records.  With different values in this
    AVP, service sessions can result in one, two, or two+N accounting
-   records, based on the needs of the home-organization.  The following
+   records, based on the needs of the home organization.  The following
    accounting record production behavior is directed by the inclusion of
    this AVP:
 
-
    1.  The omission of the Acct-Interim-Interval AVP or its inclusion
        with Value field set to 0 means that EVENT_RECORD, START_RECORD,
        and STOP_RECORD are produced, as appropriate for the service.
 
-
    2.  The inclusion of the AVP with Value field set to a non-zero value
        means that INTERIM_RECORD records MUST be produced between the
        START_RECORD and STOP_RECORD records.  The Value field of this
        AVP is the nominal interval between these records in seconds.
+       The Diameter node that originates the accounting information,
+       known as the client, MUST produce the first INTERIM_RECORD record
+       roughly at the time when this nominal interval has elapsed from
+
+
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 134]
+Fajardo, et al.              Standards Track                  [Page 130]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-       The Diameter node that originates the accounting information,
-       known as the client, MUST produce the first INTERIM_RECORD record
-       roughly at the time when this nominal interval has elapsed from
        the START_RECORD, the next one again as the interval has elapsed
        once more, and so on until the session ends and a STOP_RECORD
        record is produced.
@@ -7522,10 +7298,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
    The Accounting-Record-Number AVP (AVP Code 485) is of type Unsigned32
    and identifies this record within one session.  As Session-Id AVPs
    are globally unique, the combination of Session-Id and Accounting-
-   Record-Number AVPs is also globally unique, and can be used in
+   Record-Number AVPs is also globally unique and can be used in
    matching accounting records with confirmations.  An easy way to
    produce unique numbers is to set the value to 0 for records of type
-   EVENT_RECORD and START_RECORD, and set the value to 1 for the first
+   EVENT_RECORD and START_RECORD and set the value to 1 for the first
    INTERIM_RECORD, 2 for the second, and so on until the value for
    STOP_RECORD is one more than for the last INTERIM_RECORD.
 
@@ -7539,10 +7315,10 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
    The Acct-Multi-Session-Id AVP (AVP Code 50) is of type UTF8String,
    following the format specified in Section 8.8.  The Acct-Multi-
-   Session-Id AVP is used to link together multiple related accounting
-   sessions, where each session would have a unique Session-Id, but the
-   same Acct-Multi-Session-Id AVP.  This AVP MAY be returned by the
-   Diameter server in an authorization answer, and MUST be used in all
+   Session-Id AVP is used to link multiple related accounting sessions,
+   where each session would have a unique Session-Id but the same Acct-
+   Multi-Session-Id AVP.  This AVP MAY be returned by the Diameter
+   server in an authorization answer, and it MUST be used in all
    accounting messages for the given session.
 
 9.8.6.  Accounting-Sub-Session-Id AVP
@@ -7553,18 +7329,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
    session, and the value of this AVP MUST be monotonically increased by
    one for all new sub-sessions.  The absence of this AVP implies no
    sub-sessions are in use, with the exception of an Accounting-Request
+   whose Accounting-Record-Type is set to STOP_RECORD.  A STOP_RECORD
+   message with no Accounting-Sub-Session-Id AVP present will signal the
+   termination of all sub-sessions for a given Session-Id.
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 135]
+Fajardo, et al.              Standards Track                  [Page 131]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-   whose Accounting-Record-Type is set to STOP_RECORD.  A STOP_RECORD
-   message with no Accounting-Sub-Session-Id AVP present will signal the
-   termination of all sub-sessions for a given Session-Id.
-
 9.8.7.   Accounting-Realtime-Required AVP
 
    The Accounting-Realtime-Required AVP (AVP Code 483) is of type
@@ -7574,7 +7349,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
    if the sending of accounting records to the accounting server has
    been temporarily prevented due to, for instance, a network problem.
 
-
    DELIVER_AND_GRANT 1
 
       The AVP with Value field set to DELIVER_AND_GRANT means that the
@@ -7584,7 +7358,6 @@ Internet-Draft           Diameter Base Protocol             January 2011
       the accounting record stream to a backup server is not a reason to
       discontinue the service to the user.
 
-
    GRANT_AND_STORE 2
 
       The AVP with Value field set to GRANT_AND_STORE means that service
@@ -7594,60 +7367,51 @@ Internet-Draft           Diameter Base Protocol             January 2011
       This is the default behavior if the AVP isn't included in the
       reply from the authorization server.
 
-
    GRANT_AND_LOSE 3
 
       The AVP with Value field set to GRANT_AND_LOSE means that service
       SHOULD be granted even if the records cannot be delivered or
       stored.
 
+10.  AVP Occurrence Tables
 
+   The following tables present the AVPs defined in this document and
+   specify in which Diameter messages they MAY or MAY NOT be present.
+   AVPs that occur only inside a Grouped AVP are not shown in these
+   tables.
 
+   The tables use the following symbols:
 
+   0     The AVP MUST NOT be present in the message.
 
+   0+    Zero or more instances of the AVP MAY be present in the
+         message.
 
 
 
 
 
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 136]
+Fajardo, et al.              Standards Track                  [Page 132]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-10.  AVP Occurrence Table
-
-   The following tables presents the AVPs defined in this document, and
-   specifies in which Diameter messages they MAY be present or not.
-   AVPs that occur only inside a Grouped AVP are not shown in this
-   table.
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   The table uses the following symbols:
 
+   0-1   Zero or one instance of the AVP MAY be present in the message.
+         It is considered an error if there are more than one instance
+         of the AVP.
 
-      0 The AVP MUST NOT be present in the message.
+   1     One instance of the AVP MUST be present in the message.
 
-      0+ Zero or more instances of the AVP MAY be present in the
-      message.
-
-      0-1 Zero or one instance of the AVP MAY be present in the message.
-      It is considered an error if there are more than one instance of
-      the AVP.
-
-      1 One instance of the AVP MUST be present in the message.
-
-      1+ At least one instance of the AVP MUST be present in the
-      message.
+   1+    At least one instance of the AVP MUST be present in the
+         message.
 
 10.1.  Base Protocol Command AVP Table
 
-   The table in this section is limited to the non-accounting Command
+   The table in this section is limited to the non-Accounting Command
    Codes defined in this specification.
 
                        +-----------------------------------------------+
-                       |                  Command-Code                 |
+                       |                  Command Code                 |
                        +---+---+---+---+---+---+---+---+---+---+---+---+
    Attribute Name      |CER|CEA|DPR|DPA|DWR|DWA|RAR|RAA|ASR|ASA|STR|STA|
    --------------------+---+---+---+---+---+---+---+---+---+---+---+---+
@@ -7665,22 +7429,29 @@ Internet-Draft           Diameter Base Protocol             January 2011
    Class               |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |0+ |0+ |
    Destination-Host    |0  |0  |0  |0  |0  |0  |1  |0  |1  |0  |0-1|0  |
    Destination-Realm   |0  |0  |0  |0  |0  |0  |1  |0  |1  |0  |1  |0  |
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 137]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    Disconnect-Cause    |0  |0  |1  |0  |0  |0  |0  |0  |0  |0  |0  |0  |
    Error-Message       |0  |0-1|0  |0-1|0  |0-1|0  |0-1|0  |0-1|0  |0-1|
    Error-Reporting-Host|0  |0  |0  |0  |0  |0  |0  |0-1|0  |0-1|0  |0-1|
-   Failed-AVP          |0  |0+ |0  |0+ |0  |0+ |0  |0+ |0  |0+ |0  |0+ |
+   Failed-AVP          |0  |0-1|0  |0-1|0  |0-1|0  |0-1|0  |0-1|0  |0-1|
    Firmware-Revision   |0-1|0-1|0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |
    Host-IP-Address     |1+ |1+ |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |
    Inband-Security-Id  |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |
    Multi-Round-Time-Out|0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |0  |
+
+
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 133]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    Origin-Host         |1  |1  |1  |1  |1  |1  |1  |1  |1  |1  |1  |1  |
    Origin-Realm        |1  |1  |1  |1  |1  |1  |1  |1  |1  |1  |1  |1  |
    Origin-State-Id     |0-1|0-1|0  |0  |0-1|0-1|0-1|0-1|0-1|0-1|0-1|0-1|
@@ -7724,9 +7495,17 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 138]
+
+
+
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 134]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
                                     +-----------+
@@ -7749,6 +7528,7 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Destination-Realm             | 1   | 0   |
       Error-Reporting-Host          | 0   | 0+  |
       Event-Timestamp               | 0-1 | 0-1 |
+      Failed-AVP                    | 0   | 0-1 |
       Origin-Host                   | 1   | 1   |
       Origin-Realm                  | 1   | 1   |
       Proxy-Info                    | 0+  | 0+  |
@@ -7760,144 +7540,220 @@ Internet-Draft           Diameter Base Protocol             January 2011
       Vendor-Specific-Application-Id| 0-1 | 0-1 |
       ------------------------------+-----+-----+
 
+11.  IANA Considerations
 
+   This section provides guidance to the Internet Assigned Numbers
+   Authority (IANA) regarding registration of values related to the
+   Diameter protocol, in accordance with [RFC5226].  Existing IANA
+   registries and assignments put in place by RFC 3588 remain the same
+   unless explicitly updated or deprecated in this section.
 
+11.1.  AVP Header
 
+   As defined in Section 4, the AVP header contains three fields that
+   require IANA namespace management: the AVP Code, Vendor-ID, and Flags
+   fields.
 
 
 
 
 
 
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 139]
+Fajardo, et al.              Standards Track                  [Page 135]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-11.  IANA Considerations
+11.1.1.  AVP Codes
 
-   This section provides guidance to the Internet Assigned Numbers
-   Authority (IANA) regarding registration of values related to the
-   Diameter protocol, in accordance with BCP 26 [RFC5226].  The policies
-   and procedures for the IANA put in place by [RFC3588] applies here.
-   The criteria used by the IANA for assignment of numbers within this
-   namespace remains the same unless otherwise stated in this section.
-   Existing assignments remains the same unless explicitly updated or
-   deprecated in this secion.
+   There are multiple namespaces.  Vendors can have their own AVP Codes
+   namespace that will be identified by their Vendor-ID (also known as
+   Enterprise-Number), and they control the assignments of their vendor-
+   specific AVP Codes within their own namespace.  The absence of a
+   Vendor-ID or a Vendor-ID value of zero (0) identifies the IETF AVP
+   Codes namespace, which is under IANA control.  The AVP Codes and
+   sometimes possible values in an AVP are controlled and maintained by
+   IANA.  AVP Code 0 is not used.  AVP Codes 1-255 are managed
+   separately as RADIUS Attribute Types.  Where a Vendor-Specific AVP is
+   implemented by more than one vendor, allocation of global AVPs should
+   be encouraged instead.
+
+   AVPs may be allocated following Expert Review (by a Designated
+   Expert) with Specification Required [RFC5226].  A block allocation
+   (release of more than three AVPs at a time for a given purpose)
+   requires IETF Review [RFC5226].
 
-11.1.  Changes to AVP Header Allocation
+11.1.2.  AVP Flags
 
-   For AVP Headers, the only change is the AVP code block allocations.
-   Block allocation (release of more than 3 at a time for a given
-   purpose) now only require IETF Review as opposed to an IETF
-   Consensus.
+   Section 4.1 describes the existing AVP Flags.  The remaining bits can
+   only be assigned via a Standards Action [RFC5226].
 
 11.2.  Diameter Header
 
-   For the Diameter Header, the command code namespace allocation has
+11.2.1.  Command Codes
+
+   For the Diameter header, the Command Code namespace allocation has
    changed.  The new allocation rules are as follows:
 
-      The command code values 256 - 8,388,607 (0x100 to 0x7fffff) are
+      The Command Code values 256 - 8,388,607 (0x100 to 0x7fffff) are
       for permanent, standard commands, allocated by IETF Review
       [RFC5226].
 
       The values 8,388,608 - 16,777,213 (0x800000 - 0xfffffd) are
-      reserved for vendor-specific command codes, to be allocated on a
+      reserved for vendor-specific Command Codes, to be allocated on a
       First Come, First Served basis by IANA [RFC5226].  The request to
       IANA for a Vendor-Specific Command Code SHOULD include a reference
-      to a publicly available specification which documents the command
+      to a publicly available specification that documents the command
       in sufficient detail to aid in interoperability between
       independent implementations.  If the specification cannot be made
-      publicly available, the request for a vendor-specific command code
+      publicly available, the request for a vendor-specific Command Code
       MUST include the contact information of persons and/or entities
       responsible for authoring and maintaining the command.
 
+
+
+
+
+
+Fajardo, et al.              Standards Track                  [Page 136]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+      The values 16,777,214 and 16,777,215 (hexadecimal values 0xfffffe
+      - 0xffffff) are reserved for experimental commands.  As these
+      codes are only for experimental and testing purposes, no guarantee
+      is made for interoperability between Diameter peers using
+      experimental commands.
+
+11.2.2.  Command Flags
+
+   Section 3 describes the existing Command Flags field.  The remaining
+   bits can only be assigned via a Standards Action [RFC5226].
+
 11.3.  AVP Values
 
    For AVP values, the Experimental-Result-Code AVP value allocation has
-   been added.  The new rule is as follows:
+   been added; see Section 11.3.1.  The old AVP value allocation rule,
+   IETF Consensus, has been updated to IETF Review as per [RFC5226], and
+   affected AVPs are listed as reminders.
 
 11.3.1.  Experimental-Result-Code AVP
 
    Values for this AVP are purely local to the indicated vendor, and no
    IANA registry is maintained for them.
 
+11.3.2.  Result-Code AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
+11.3.3.  Accounting-Record-Type AVP Values
 
-Fajardo, et al.           Expires July 24, 2011               [Page 140]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   New values are available for assignment via IETF Review [RFC5226].
+
+11.3.4.  Termination-Cause AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
-11.4.  Diameter TCP, SCTP, TLS/TCP and DTLS/SCTP Port Numbers
+11.3.5.  Redirect-Host-Usage AVP Values
 
-   Updated port number assignments are described in this section.  The
-   IANA has assigned port number 3868 for TCP and SCTP.  The port number
-   [TBD] has been assigned for TLS/TCP and DTLS/SCTP.
+   New values are available for assignment via IETF Review [RFC5226].
 
-11.5.  S-NAPTR Parameters
+11.3.6.  Session-Server-Failover AVP Values
 
-   This document registers a new S-NAPTR Application Service Tag value
-   of "aaa".
+   New values are available for assignment via IETF Review [RFC5226].
 
-   This document also registers the following S-NAPTR Application
-   Protocol Tags:
+11.3.7.  Session-Binding AVP Values
 
-     Tag                | Protocol
-     -------------------|---------
-     diameter.tcp       | TCP
-     diameter.sctp      | SCTP
-     diameter.tls.tcp   | TLS/TCP
-     diameter.dtls.sctp | DTLS/SCTP
+   New values are available for assignment via IETF Review [RFC5226].
 
 
 
 
 
+Fajardo, et al.              Standards Track                  [Page 137]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+11.3.8.  Disconnect-Cause AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
+11.3.9.  Auth-Request-Type AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
+11.3.10.  Auth-Session-State AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
+11.3.11.  Re-Auth-Request-Type AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
+11.3.12.  Accounting-Realtime-Required AVP Values
 
+   New values are available for assignment via IETF Review [RFC5226].
 
+11.3.13.  Inband-Security-Id AVP (code 299)
 
+   The use of this AVP has been deprecated.
 
+11.4.  _diameters Service Name and Port Number Registration
 
+   IANA has registered the "_diameters" service name and assigned port
+   numbers for TLS/TCP and DTLS/SCTP according to the guidelines given
+   in [RFC6335].
 
+      Service Name:         _diameters
 
+      Transport Protocols:  TCP, SCTP
 
+      Assignee:             IESG <[email protected]>
 
+      Contact:              IETF Chair <[email protected]>
 
+      Description:          Diameter over TLS/TCP and DTLS/SCTP
 
+      Reference:            RFC 6733
 
+      Port  Number:         5868, from the User Range
 
 
 
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 141]
+
+
+Fajardo, et al.              Standards Track                  [Page 138]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+11.5.  SCTP Payload Protocol Identifiers
+
+   Two SCTP payload protocol identifiers have been registered in the
+   SCTP Payload Protocol Identifiers registry:
+
+
+    Value | SCTP Payload Protocol Identifier
+   -------|-----------------------------------
+     46   | Diameter in a SCTP DATA chunk
+     47   | Diameter in a DTLS/SCTP DATA chunk
+
 
+11.6.  S-NAPTR Parameters
 
-12.  Diameter protocol related configurable parameters
+   The following tag has been registered in the S-NAPTR Application
+   Protocol Tags registry:
+
+   Tag                | Protocol
+   -------------------|---------
+   diameter.dtls.sctp | DTLS/SCTP
+
+12.  Diameter Protocol-Related Configurable Parameters
 
    This section contains the configurable parameters that are found
    throughout this document:
@@ -7915,8 +7771,8 @@ Internet-Draft           Diameter Base Protocol             January 2011
       A Diameter proxy server routes messages based on the realm portion
       of a Network Access Identifier (NAI).  The server MUST have a
       table of Realm Names, and the address of the peer to which the
-      message must be forwarded to.  The routing table MAY also include
-      a "default route", which is typically used for all messages that
+      message must be forwarded.  The routing table MAY also include a
+      "default route", which is typically used for all messages that
       cannot be locally processed.
 
    Tc timer
@@ -7927,30 +7783,9 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 142]
+Fajardo, et al.              Standards Track                  [Page 139]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 13.  Security Considerations
@@ -7959,34 +7794,34 @@ Internet-Draft           Diameter Base Protocol             January 2011
    [RFC5246] or DTLS/SCTP [RFC6083].  Additional security mechanisms
    such as IPsec [RFC4301] MAY also be deployed to secure connections
    between peers.  However, all Diameter base protocol implementations
-   MUST support the use of TLS/TCP and DTLS/SCTP and the Diameter
-   protocol MUST NOT be used without any security mechanism.
+   MUST support the use of TLS/TCP and DTLS/SCTP, and the Diameter
+   protocol MUST NOT be used without one of TLS, DTLS, or IPsec.
 
    If a Diameter connection is to be protected via TLS/TCP and DTLS/SCTP
    or IPsec, then TLS/TCP and DTLS/SCTP or IPsec/IKE SHOULD begin prior
    to any Diameter message exchange.  All security parameters for TLS/
    TCP and DTLS/SCTP or IPsec are configured independent of the Diameter
-   protocol.  All Diameter message will be sent through the TLS/TCP and
+   protocol.  All Diameter messages will be sent through the TLS/TCP and
    DTLS/SCTP or IPsec connection after a successful setup.
 
    For TLS/TCP and DTLS/SCTP connections to be established in the open
    state, the CER/CEA exchange MUST include an Inband-Security-ID AVP
    with a value of TLS/TCP and DTLS/SCTP.  The TLS/TCP and DTLS/SCTP
-   handshake will begin when both ends successfully reached the open
+   handshake will begin when both ends successfully reach the open
    state, after completion of the CER/CEA exchange.  If the TLS/TCP and
    DTLS/SCTP handshake is successful, all further messages will be sent
-   via TLS/TCP and DTLS/SCTP.  If the handshake fails, both ends move to
-   the closed state.  See Sections 13.1 for more details.
+   via TLS/TCP and DTLS/SCTP.  If the handshake fails, both ends MUST
+   move to the closed state.  See Section 13.1 for more details.
 
 13.1.  TLS/TCP and DTLS/SCTP Usage
 
    Diameter nodes using TLS/TCP and DTLS/SCTP for security MUST mutually
    authenticate as part of TLS/TCP and DTLS/SCTP session establishment.
    In order to ensure mutual authentication, the Diameter node acting as
-   TLS/TCP and DTLS/SCTP server MUST request a certificate from the
+   the TLS/TCP and DTLS/SCTP server MUST request a certificate from the
    Diameter node acting as TLS/TCP and DTLS/SCTP client, and the
-   Diameter node acting as TLS/TCP and DTLS/SCTP client MUST be prepared
-   to supply a certificate on request.
+   Diameter node acting as the TLS/TCP and DTLS/SCTP client MUST be
+   prepared to supply a certificate on request.
 
    Diameter nodes MUST be able to negotiate the following TLS/TCP and
    DTLS/SCTP cipher suites:
@@ -8000,16 +7835,24 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
          TLS_RSA_WITH_AES_128_CBC_SHA
 
-   Diameter nodes MAY negotiate other TLS/TCP and DTLS/SCTP cipher
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 143]
+
+Fajardo, et al.              Standards Track                  [Page 140]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   Note that it is quite possible that support for the
+   TLS_RSA_WITH_AES_128_CBC_SHA cipher suite will be REQUIRED at some
+   future date.  Diameter nodes MAY negotiate other TLS/TCP and DTLS/
+   SCTP cipher suites.
 
-   suites.
+   If public key certificates are used for Diameter security (for
+   example, with TLS), the value of the expiration times in the routing
+   and peer tables MUST NOT be greater than the expiry time in the
+   relevant certificates.
 
 13.2.  Peer-to-Peer Considerations
 
@@ -8027,67 +7870,105 @@ Internet-Draft           Diameter Base Protocol             January 2011
    peers may not be known beforehand and therefore peer discovery may be
    required.
 
+13.3.  AVP Considerations
 
+   Diameter AVPs often contain security-sensitive data; for example,
+   user passwords and location data, network addresses and cryptographic
+   keys.  The following AVPs defined in this document are considered to
+   be security-sensitive:
 
+   o  Acct-Interim-Interval
 
+   o  Accounting-Realtime-Required
 
+   o  Acct-Multi-Session-Id
 
+   o  Accounting-Record-Number
 
+   o  Accounting-Record-Type
 
+   o  Accounting-Session-Id
 
+   o  Accounting-Sub-Session-Id
 
+   o  Class
 
 
 
+Fajardo, et al.              Standards Track                  [Page 141]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
+   o  Session-Id
 
+   o  Session-Binding
 
+   o  Session-Server-Failover
 
+   o  User-Name
 
+   Diameter messages containing these or any other AVPs considered to be
+   security-sensitive MUST only be sent protected via mutually
+   authenticated TLS or IPsec.  In addition, those messages MUST NOT be
+   sent via intermediate nodes unless there is end-to-end security
+   between the originator and recipient or the originator has locally
+   trusted configuration that indicates that end-to-end security is not
+   needed.  For example, end-to-end security may not be required in the
+   case where an intermediary node is known to be operated as part of
+   the same administrative domain as the endpoints so that an ability to
+   successfully compromise the intermediary would imply a high
+   probability of being able to compromise the endpoints as well.  Note
+   that no end-to-end security mechanism is specified in this document.
 
+14.  References
 
+14.1.  Normative References
 
+   [FLOATPOINT]
+              Institute of Electrical and Electronics Engineers, "IEEE
+              Standard for Binary Floating-Point Arithmetic, ANSI/IEEE
+              Standard 754-1985", August 1985.
 
+   [IANAADFAM]
+              IANA, "Address Family Numbers",
+              <http://www.iana.org/assignments/address-family-numbers>.
 
+   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
+              September 1981.
 
+   [RFC0793]  Postel, J., "Transmission Control Protocol", STD 7,
+              RFC 793, September 1981.
 
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
 
+   [RFC3492]  Costello, A., "Punycode: A Bootstring encoding of Unicode
+              for Internationalized Domain Names in Applications
+              (IDNA)", RFC 3492, March 2003.
 
 
 
 
 
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 144]
+Fajardo, et al.              Standards Track                  [Page 142]
 
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
-14.  References
-
-14.1.  Normative References
-
-   [FLOATPOINT]
-              Institute of Electrical and Electronics Engineers, "IEEE
-              Standard for Binary Floating-Point Arithmetic, ANSI/IEEE
-              Standard 754-1985", August 1985.
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   [IANAADFAM]
-              IANA,, "Address Family Numbers",
-               http://www.iana.org/assignments/address-family-numbers.
 
-   [RADTYPE]  IANA,, "RADIUS Types",
-               http://www.iana.org/assignments/radius-types.
+   [RFC3539]  Aboba, B. and J. Wood, "Authentication, Authorization and
+              Accounting (AAA) Transport Profile", RFC 3539, June 2003.
 
-   [RFC791]   Postel, J., "Internet Protocol", RFC 791, September 1981.
+   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
+              10646", STD 63, RFC 3629, November 2003.
 
-   [RFC793]   Postel, J., "Transmission Control Protocol", RFC 793,
-              January 1981.
+   [RFC3958]  Daigle, L. and A. Newton, "Domain-Based Application
+              Service Location Using SRV RRs and the Dynamic Delegation
+              Discovery Service (DDDS)", RFC 3958, January 2005.
 
-   [RFC3539]  Aboba, B. and J. Wood, "Authentication, Authorization and
-              Accounting (AAA) Transport Profile", RFC 3539, June 2003.
+   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
+              Resource Identifier (URI): Generic Syntax", STD 66,
+              RFC 3986, January 2005.
 
    [RFC4004]  Calhoun, P., Johansson, T., Perkins, C., Hiller, T., and
               P. McCann, "Diameter Mobile IPv4 Application", RFC 4004,
@@ -8101,51 +7982,44 @@ Internet-Draft           Diameter Base Protocol             January 2011
               Loughney, "Diameter Credit-Control Application", RFC 4006,
               August 2005.
 
-   [RFC5234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
-              Specifications: ABNF", STD 68, RFC 5234, January 2008.
-
-   [RFC3588]  Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
-              Arkko, "Diameter Base Protocol", RFC 3588, September 2003.
+   [RFC4086]  Eastlake, D., Schiller, J., and S. Crocker, "Randomness
+              Requirements for Security", BCP 106, RFC 4086, June 2005.
 
-   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
-              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
-              May 2008.
+   [RFC4282]  Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The
+              Network Access Identifier", RFC 4282, December 2005.
 
    [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
               Architecture", RFC 4291, February 2006.
 
+   [RFC4960]  Stewart, R., "Stream Control Transmission Protocol",
+              RFC 4960, September 2007.
 
+   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
+              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
+              May 2008.
 
-Fajardo, et al.           Expires July 24, 2011               [Page 145]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
+   [RFC5234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
+              Specifications: ABNF", STD 68, RFC 5234, January 2008.
 
-   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
-              Requirement Levels", BCP 14, RFC 2119, March 1997.
+   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
+              (TLS) Protocol Version 1.2", RFC 5246, August 2008.
 
-   [RFC4282]  Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The
-              Network Access Identifier", RFC 4282, December 2005.
 
-   [RFC4086]  Eastlake, D., Schiller, J., and S. Crocker, "Randomness
-              Requirements for Security", BCP 106, RFC 4086, June 2005.
 
-   [RFC4960]  Stewart, R., "Stream Control Transmission Protocol",
-              RFC 4960, September 2007.
 
-   [RFC3958]  Daigle, L. and A. Newton, "Domain-Based Application
-              Service Location Using SRV RRs and the Dynamic Delegation
-              Discovery Service (DDDS)", RFC 3958, January 2005.
+Fajardo, et al.              Standards Track                  [Page 143]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
-              (TLS) Protocol Version 1.2", RFC 5246, August 2008.
 
-   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
-              Resource Identifier (URI): Generic Syntax", STD 66,
-              RFC 3986, January 2005.
+   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
+              Housley, R., and W. Polk, "Internet X.509 Public Key
+              Infrastructure Certificate and Certificate Revocation List
+              (CRL) Profile", RFC 5280, May 2008.
 
-   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
-              10646", STD 63, RFC 3629, November 2003.
+   [RFC5729]  Korhonen, J., Jones, M., Morand, L., and T. Tsou,
+              "Clarifications on the Routing of Diameter Requests Based
+              on the Username and the Realm", RFC 5729, December 2009.
 
    [RFC5890]  Klensin, J., "Internationalized Domain Names for
               Applications (IDNA): Definitions and Document Framework",
@@ -8154,103 +8028,120 @@ Internet-Draft           Diameter Base Protocol             January 2011
    [RFC5891]  Klensin, J., "Internationalized Domain Names in
               Applications (IDNA): Protocol", RFC 5891, August 2010.
 
-   [RFC3492]  Costello, A., "Punycode: A Bootstring encoding of Unicode
-              for Internationalized Domain Names in Applications
-              (IDNA)", RFC 3492, March 2003.
-
-   [RFC5729]  Korhonen, J., Jones, M., Morand, L., and T. Tsou,
-              "Clarifications on the Routing of Diameter Requests Based
-              on the Username and the Realm", RFC 5729, December 2009.
-
-   [RFC4347]  Rescorla, E. and N. Modadugu, "Datagram Transport Layer
-              Security", RFC 4347, April 2006.
-
    [RFC6083]  Tuexen, M., Seggelmann, R., and E. Rescorla, "Datagram
               Transport Layer Security (DTLS) for Stream Control
               Transmission Protocol (SCTP)", RFC 6083, January 2011.
 
+   [RFC6347]  Rescorla, E. and N. Modadugu, "Datagram Transport Layer
+              Security Version 1.2", RFC 6347, January 2012.
 
+   [RFC6408]  Jones, M., Korhonen, J., and L. Morand, "Diameter
+              Straightforward-Naming Authority Pointer (S-NAPTR) Usage",
+              RFC 6408, November 2011.
 
+14.2.  Informative References
 
-Fajardo, et al.           Expires July 24, 2011               [Page 146]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   [ENTERPRISE]  IANA, "SMI Network Management Private Enterprise
+                 Codes",
+                 <http://www.iana.org/assignments/enterprise-numbers>.
 
+   [IANATCV]     IANA, "Termination-Cause AVP Values (code 295)",
+                 <http://www.iana.org/assignments/aaa-parameters/
+                 aaa-parameters.xml#aaa-parameters-16>.
 
-14.2.  Informational References
+   [RFC1492]     Finseth, C., "An Access Control Protocol, Sometimes
+                 Called TACACS", RFC 1492, July 1993.
 
-   [RFC2989]  Aboba, B., Calhoun, P., Glass, S., Hiller, T., McCann, P.,
-              Shiino, H., Walsh, P., Zorn, G., Dommety, G., Perkins, C.,
-              Patil, B., Mitton, D., Manning, S., Beadles, M., Chen, X.,
-              Sivalingham, S., Hameed, A., Munson, M., Jacobs, S., Lim,
-              B., Hirschman, B., Hsu, R., Koo, H., Lipford, M.,
-              Campbell, E., Xu, Y., Baba, S., and E. Jaques, "Criteria
-              for Evaluating AAA Protocols for Network Access",
-              RFC 2989, November 2000.
+   [RFC1661]     Simpson, W., "The Point-to-Point Protocol (PPP)",
+                 STD 51, RFC 1661, July 1994.
 
-   [RFC2975]  Aboba, B., Arkko, J., and D. Harrington, "Introduction to
-              Accounting Management", RFC 2975, October 2000.
+   [RFC2104]     Krawczyk, H., Bellare, M., and R. Canetti, "HMAC:
+                 Keyed-Hashing for Message Authentication", RFC 2104,
+                 February 1997.
 
-   [RFC3232]  Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by
-              an On-line Database", RFC 3232, January 2002.
 
-   [RFC5176]  Chiba, M., Dommety, G., Eklund, M., Mitton, D., and B.
-              Aboba, "Dynamic Authorization Extensions to Remote
-              Authentication Dial In User Service (RADIUS)", RFC 5176,
-              January 2008.
 
-   [RFC1661]  Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51,
-              RFC 1661, July 1994.
 
-   [RFC2866]  Rigney, C., "RADIUS Accounting", RFC 2866, June 2000.
 
-   [RFC2869]  Rigney, C., Willats, W., and P. Calhoun, "RADIUS
-              Extensions", RFC 2869, June 2000.
+Fajardo, et al.              Standards Track                  [Page 144]
+
+RFC 6733                 Diameter Base Protocol             October 2012
 
-   [RFC2865]  Rigney, C., Willens, S., Rubens, A., and W. Simpson,
-              "Remote Authentication Dial In User Service (RADIUS)",
-              RFC 2865, June 2000.
 
-   [RFC3162]  Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6",
-              RFC 3162, August 2001.
+   [RFC2782]     Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR
+                 for specifying the location of services (DNS SRV)",
+                 RFC 2782, February 2000.
 
-   [RFC4301]  Kent, S. and K. Seo, "Security Architecture for the
-              Internet Protocol", RFC 4301, December 2005.
+   [RFC2865]     Rigney, C., Willens, S., Rubens, A., and W. Simpson,
+                 "Remote Authentication Dial In User Service (RADIUS)",
+                 RFC 2865, June 2000.
 
-   [RFC5905]  Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
-              Time Protocol Version 4: Protocol and Algorithms
-              Specification", RFC 5905, June 2010.
+   [RFC2866]     Rigney, C., "RADIUS Accounting", RFC 2866, June 2000.
 
-   [RFC1492]  Finseth, C., "An Access Control Protocol, Sometimes Called
-              TACACS", RFC 1492, July 1993.
+   [RFC2869]     Rigney, C., Willats, W., and P. Calhoun, "RADIUS
+                 Extensions", RFC 2869, June 2000.
 
-   [RFC4690]  Klensin, J., Faltstrom, P., Karp, C., and IAB, "Review and
+   [RFC2881]     Mitton, D. and M. Beadles, "Network Access Server
+                 Requirements Next Generation (NASREQNG) NAS Model",
+                 RFC 2881, July 2000.
 
+   [RFC2975]     Aboba, B., Arkko, J., and D. Harrington, "Introduction
+                 to Accounting Management", RFC 2975, October 2000.
 
+   [RFC2989]     Aboba, B., Calhoun, P., Glass, S., Hiller, T., McCann,
+                 P., Shiino, H., Walsh, P., Zorn, G., Dommety, G.,
+                 Perkins, C., Patil, B., Mitton, D., Manning, S.,
+                 Beadles, M., Chen, X., Sivalingham, S., Hameed, A.,
+                 Munson, M., Jacobs, S., Lim, B., Hirschman, B., Hsu,
+                 R., Koo, H., Lipford, M., Campbell, E., Xu, Y., Baba,
+                 S., and E. Jaques, "Criteria for Evaluating AAA
+                 Protocols for Network Access", RFC 2989, November 2000.
 
-Fajardo, et al.           Expires July 24, 2011               [Page 147]
-
-Internet-Draft           Diameter Base Protocol             January 2011
+   [RFC3162]     Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6",
+                 RFC 3162, August 2001.
 
+   [RFC3748]     Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and
+                 H. Levkowetz, "Extensible Authentication Protocol
+                 (EAP)", RFC 3748, June 2004.
 
-              Recommendations for Internationalized Domain Names
-              (IDNs)", RFC 4690, September 2006.
+   [RFC4301]     Kent, S. and K. Seo, "Security Architecture for the
+                 Internet Protocol", RFC 4301, December 2005.
 
-   [RFC5461]  Gont, F., "TCP's Reaction to Soft Errors", RFC 5461,
-              February 2009.
+   [RFC4690]     Klensin, J., Faltstrom, P., Karp, C., and IAB, "Review
+                 and Recommendations for Internationalized Domain Names
+                 (IDNs)", RFC 4690, September 2006.
 
-   [RFC5927]  Gont, F., "ICMP Attacks against TCP", RFC 5927, July 2010.
+   [RFC5176]     Chiba, M., Dommety, G., Eklund, M., Mitton, D., and B.
+                 Aboba, "Dynamic Authorization Extensions to Remote
+                 Authentication Dial In User Service (RADIUS)",
+                 RFC 5176, January 2008.
 
-   [RFC3692]  Narten, T., "Assigning Experimental and Testing Numbers
-              Considered Useful", BCP 82, RFC 3692, January 2004.
 
 
 
+Fajardo, et al.              Standards Track                  [Page 145]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
 
+   [RFC5461]     Gont, F., "TCP's Reaction to Soft Errors", RFC 5461,
+                 February 2009.
 
+   [RFC5905]     Mills, D., Martin, J., Burbank, J., and W. Kasch,
+                 "Network Time Protocol Version 4: Protocol and
+                 Algorithms Specification", RFC 5905, June 2010.
 
+   [RFC5927]     Gont, F., "ICMP Attacks against TCP", RFC 5927,
+                 July 2010.
 
+   [RFC6335]     Cotton, M., Eggert, L., Touch, J., Westerlund, M., and
+                 S. Cheshire, "Internet Assigned Numbers Authority
+                 (IANA) Procedures for the Management of the Service
+                 Name and Transport Protocol Port Number Registry",
+                 BCP 165, RFC 6335, August 2011.
 
+   [RFC6737]     Kang, J. and G. Zorn, "The Diameter Capabilities Update
+                 Application", RFC 6737, October 2012.
 
 
 
@@ -8284,80 +8175,83 @@ Internet-Draft           Diameter Base Protocol             January 2011
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 148]
+Fajardo, et al.              Standards Track                  [Page 146]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 Appendix A.  Acknowledgements
 
-A.1.  RFC3588bis
+A.1.  This Document
 
    The authors would like to thank the following people that have
    provided proposals and contributions to this document:
 
    To Vishnu Ram and Satendra Gera for their contributions on
-   Capabilities Updates, Predictive Loop Avoidance as well as many other
-   technical proposals.  To Tolga Asveren for his insights and
+   capabilities updates, predictive loop avoidance, as well as many
+   other technical proposals.  To Tolga Asveren for his insights and
    contributions on almost all of the proposed solutions incorporated
-   into this document.  To Timothy Smith for helping on the Capabilities
-   Updates and other topics.  To Tony Zhang for providing fixes to loop
-   holes on composing Failed-AVPs as well as many other issues and
+   into this document.  To Timothy Smith for helping on the capabilities
+   Update and other topics.  To Tony Zhang for providing fixes to
+   loopholes on composing Failed-AVPs as well as many other issues and
    topics.  To Jan Nordqvist for clearly stating the usage of
-   Application Ids. To Anders Kristensen for providing needed technical
+   Application Ids.  To Anders Kristensen for providing needed technical
    opinions.  To David Frascone for providing invaluable review of the
    document.  To Mark Jones for providing clarifying text on vendor
-   command codes and other vendor specific indicators.
+   command codes and other vendor-specific indicators.  To Victor
+   Pascual and Sebastien Decugis for new text and recommendations on
+   SCTP/DTLS.  To Jouni Korhonen for taking over the editing task and
+   resolving last bits from versions 27 through 29.
 
-   Special thanks to the Diameter extensibility design team which helped
-   resolve the tricky question of mandatory AVPs and ABNF semantics.
-   The members of this team are as follows:
+   Special thanks to the Diameter extensibility design team, which
+   helped resolve the tricky question of mandatory AVPs and ABNF
+   semantics.  The members of this team are as follows:
 
    Avi Lior, Jari Arkko, Glen Zorn, Lionel Morand, Mark Jones, Tolga
-   Asveren Jouni Korhonen, Glenn McGregor.
+   Asveren, Jouni Korhonen, and Glenn McGregor.
 
    Special thanks also to people who have provided invaluable comments
    and inputs especially in resolving controversial issues:
 
-   Glen Zorn, Yoshihiro Ohba, Marco Stura, and Pasi Eronen.
+   Glen Zorn, Yoshihiro Ohba, Marco Stura, Stephen Farrel, Pete Resnick,
+   Peter Saint-Andre, Robert Sparks, Krishna Prasad, Sean Turner, Barry
+   Leiba, and Pasi Eronen.
 
    Finally, we would like to thank the original authors of this
    document:
 
-   Pat Calhoun, John Loughney, Jari Arkko, Erik Guttman and Glen Zorn.
+   Pat Calhoun, John Loughney, Jari Arkko, Erik Guttman, and Glen Zorn.
 
    Their invaluable knowledge and experience has given us a robust and
    flexible AAA protocol that many people have seen great value in
    adopting.  We greatly appreciate their support and stewardship for
    the continued improvements of Diameter as a protocol.  We would also
    like to extend our gratitude to folks aside from the authors who have
-   assisted and contributed to the original version of this document.
-   Their efforts significantly contributed to the success of Diameter.
-
 
 
 
 
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 149]
+Fajardo, et al.              Standards Track                  [Page 147]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
-A.2.  RFC3588
+   assisted and contributed to the original version of this document.
+   Their efforts significantly contributed to the success of Diameter.
+
+A.2.  RFC 3588
 
    The authors would like to thank Nenad Trifunovic, Tony Johansson and
    Pankaj Patel for their participation in the pre-IETF Document Reading
-   Party.  Allison Mankin, Jonathan Wood and Bernard Aboba provided
-   invaluable assistance in working out transport issues, and similarly
-   with Steven Bellovin in the security area.
+   Party.  Allison Mankin, Jonathan Wood, and Bernard Aboba provided
+   invaluable assistance in working out transport issues and this was
+   also the case with Steven Bellovin in the security area.
 
    Paul Funk and David Mitton were instrumental in getting the Peer
    State Machine correct, and our deep thanks go to them for their time.
 
    Text in this document was also provided by Paul Funk, Mark Eklund,
-   Mark Jones and Dave Spence.  Jacques Caron provided many great
+   Mark Jones, and Dave Spence.  Jacques Caron provided many great
    comments as a result of a thorough review of the spec.
 
    The authors would also like to acknowledge the following people for
@@ -8367,96 +8261,57 @@ A.2.  RFC3588
    David Frascone, Daniel C. Fox, Lol Grant, Ignacio Goyret, Nancy
    Greene, Peter Heitman, Fredrik Johansson, Mark Jones, Martin Julien,
    Bob Kopacz, Paul Krumviede, Fergal Ladley, Ryan Moats, Victor Muslin,
-   Kenneth Peirce, John Schnizlein, Sumit Vakil, John R. Vollbrecht and
+   Kenneth Peirce, John Schnizlein, Sumit Vakil, John R. Vollbrecht, and
    Jeff Weisberg.
 
    Finally, Pat Calhoun would like to thank Sun Microsystems since most
    of the effort put into this document was done while he was in their
    employ.
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 150]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 Appendix B.  S-NAPTR Example
 
    As an example, consider a client that wishes to resolve aaa:
-   example1.com.  The client performs a NAPTR query for that domain, and
-   the following NAPTR records are returned:
+   ex1.example.com.  The client performs a NAPTR query for that domain,
+   and the following NAPTR records are returned:
 
     ;;        order pref flags service   regexp replacement
     IN NAPTR  50    50   "s"   "aaa:diameter.tls.tcp" ""
-                 _diameter._tls.example1.com
+                 _diameter._tls.ex1.example.com
     IN NAPTR  100   50   "s"   "aaa:diameter.tcp"     ""
-                 _aaa._tcp.example1.com
+                 _aaa._tcp.ex1.example.com
     IN NAPTR  150   50   "s"   "aaa:diameter.sctp"    ""
-                 _diameter._sctp.example1.com
+                 _diameter._sctp.ex1.example.com
 
-   This indicates that the server supports TLS, TCP and SCTP in that
+   This indicates that the server supports TLS, TCP, and SCTP in that
    order.  If the client supports TLS, TLS will be used, targeted to a
-   host determined by an SRV lookup of _diameter._tls.example1.com.
+
+
+
+Fajardo, et al.              Standards Track                  [Page 148]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
+   host determined by an SRV lookup of _diameter._tls.ex1.example.com.
    That lookup would return:
 
     ;;       Priority  Weight  Port    Target
-    IN SRV   0         1       5060    server1.example1.com
-    IN SRV   0         2       5060    server2.example1.com
+    IN SRV   0         1       5060    server1.ex1.example.com
+    IN SRV   0         2       5060    server2.ex1.example.com
 
    As an alternative example, a client that wishes to resolve aaa:
-   example2.com.  The client performs a NAPTR query for that domain, and
-   the following NAPTR records are returned:
+   ex2.example.com.  The client performs a NAPTR query for that domain,
+   and the following NAPTR records are returned:
 
     ;;        order pref flags service   regexp replacement
     IN NAPTR  150   50   "a"   "aaa:diameter.tls.tcp"  ""
-                 server1.example2.com
+                 server1.ex2.example.com
     IN NAPTR  150   50   "a"   "aaa:diameter.tls.tcp"  ""
-                 server2.example2.com
+                 server2.ex2.example.com
 
    This indicates that the server supports TCP available at the returned
    host names.
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 151]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 Appendix C.  Duplicate Detection
 
    As described in Section 9.4, accounting record duplicate detection is
@@ -8464,14 +8319,14 @@ Appendix C.  Duplicate Detection
    reasons:
 
    o  Failover to an alternate server.  Where close to real-time
-      performance is required, failover thresholds need to be kept low
-      and this may lead to an increased likelihood of duplicates.
-      Failover can occur at the client or within Diameter agents.
-
-   o  Failure of a client or agent after sending of a record from non-
-      volatile memory, but prior to receipt of an application layer ACK
-      and deletion of the record. record to be sent.  This will result
-      in retransmission of the record soon after the client or agent has
+      performance is required, failover thresholds need to be kept low.
+      This may lead to an increased likelihood of duplicates.  Failover
+      can occur at the client or within Diameter agents.
+
+   o  Failure of a client or agent after sending a record from non-
+      volatile memory, but prior to receipt of an application-layer ACK
+      and deletion of the record to be sent.  This will result in
+      retransmission of the record soon after the client or agent has
       rebooted.
 
    o  Duplicates received from RADIUS gateways.  Since the
@@ -8481,48 +8336,48 @@ Appendix C.  Duplicate Detection
 
    o  Implementation problems and misconfiguration.
 
-   The T flag is used as an indication of an application layer
+   The T flag is used as an indication of an application-layer
    retransmission event, e.g., due to failover to an alternate server.
    It is defined only for request messages sent by Diameter clients or
    agents.  For instance, after a reboot, a client may not know whether
+
+
+
+Fajardo, et al.              Standards Track                  [Page 149]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
    it has already tried to send the accounting records in its non-
    volatile memory before the reboot occurred.  Diameter servers MAY use
    the T flag as an aid when processing requests and detecting duplicate
    messages.  However, servers that do this MUST ensure that duplicates
    are found even when the first transmitted request arrives at the
    server after the retransmitted request.  It can be used only in cases
-   where no answer has been received from the Server for a request and
+   where no answer has been received from the server for a request and
    the request is sent again, (e.g., due to a failover to an alternate
    peer, due to a recovered primary peer or due to a client re-sending a
    stored record from non-volatile memory such as after reboot of a
    client or agent).
 
-   In some cases the Diameter accounting server can delay the duplicate
+   In some cases, the Diameter accounting server can delay the duplicate
    detection and accounting record processing until a post-processing
    phase takes place.  At that time records are likely to be sorted
    according to the included User-Name and duplicate elimination is easy
-   in this case.  In other situations it may be necessary to perform
+   in this case.  In other situations, it may be necessary to perform
    real-time duplicate detection, such as when credit limits are imposed
    or real-time fraud detection is desired.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 152]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
    In general, only generation of duplicates due to failover or re-
    sending of records in non-volatile storage can be reliably detected
-   by Diameter clients or agents.  In such cases the Diameter client or
-   agents can mark the message as possible duplicate by setting the T
+   by Diameter clients or agents.  In such cases, the Diameter client or
+   agents can mark the message as a possible duplicate by setting the T
    flag.  Since the Diameter server is responsible for duplicate
-   detection, it can choose to make use of the T flag or not, in order
-   to optimize duplicate detection.  Since the T flag does not affect
-   interoperability, and may not be needed by some servers, generation
-   of the T flag is REQUIRED for Diameter clients and agents, but MAY be
-   implemented by Diameter servers.
+   detection, it can choose whether or not to make use of the T flag, in
+   order to optimize duplicate detection.  Since the T flag does not
+   affect interoperability, and it may not be needed by some servers,
+   generation of the T flag is REQUIRED for Diameter clients and agents,
+   but it MAY be implemented by Diameter servers.
 
    As an example, it can be usually be assumed that duplicates appear
    within a time window of longest recorded network partition or device
@@ -8535,40 +8390,39 @@ Internet-Draft           Diameter Base Protocol             January 2011
    The following is an example of how the T flag may be used by the
    server to detect duplicate requests.
 
-
       A Diameter server MAY check the T flag of the received message to
       determine if the record is a possible duplicate.  If the T flag is
       set in the request message, the server searches for a duplicate
       within a configurable duplication time window backward and
       forward.  This limits database searching to those records where
-      the T flag is set.  In a well run network, network partitions and
+      the T flag is set.  In a well-run network, network partitions and
+
+
+
+Fajardo, et al.              Standards Track                  [Page 150]
+
+RFC 6733                 Diameter Base Protocol             October 2012
+
+
       device faults will presumably be rare events, so this approach
       represents a substantial optimization of the duplicate detection
       process.  During failover, it is possible for the original record
-      to be received after the T flag marked record, due to differences
+      to be received after the T-flag-marked record, due to differences
       in network delays experienced along the path by the original and
       duplicate transmissions.  The likelihood of this occurring
       increases as the failover interval is decreased.  In order to be
-      able to detect out of order duplicates, the Diameter server should
-      use backward and forward time windows when performing duplicate
-      checking for the T flag marked request.  For example, in order to
-      allow time for the original record to exit the network and be
-      recorded by the accounting server, the Diameter server can delay
-      processing records with the T flag set until a time period
-      TIME_WAIT + RECORD_PROCESSING_TIME has elapsed after the closing
-      of the original transport connection.  After this time period has
-      expired, then it may check the T flag marked records against the
+      able to detect duplicates that are out of order, the Diameter
+      server should use backward and forward time windows when
+      performing duplicate checking for the T-flag-marked request.  For
+      example, in order to allow time for the original record to exit
+      the network and be recorded by the accounting server, the Diameter
+      server can delay processing records with the T flag set until a
+      time period TIME_WAIT + RECORD_PROCESSING_TIME has elapsed after
+      the closing of the original transport connection.  After this time
+      period, it may check the T-flag-marked records against the
       database with relative assurance that the original records, if
       sent, have been received and recorded.
 
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 153]
-
-Internet-Draft           Diameter Base Protocol             January 2011
-
-
 Appendix D.  Internationalized Domain Names
 
    To be compatible with the existing DNS infrastructure and simplify
@@ -8579,14 +8433,7 @@ Appendix D.  Internationalized Domain Names
    recommendations in [RFC4690] and [RFC5890].  Applications that
    provide support for IDNs outside of the Diameter protocol but
    interacting with it SHOULD use the representation and conversion
-   framework described in [RFC5890], [RFC5891] and [RFC3492].
-
-
-
-
-
-
-
+   framework described in [RFC5890], [RFC5891], and [RFC3492].
 
 
 
@@ -8608,21 +8455,9 @@ Appendix D.  Internationalized Domain Names
 
 
 
-
-
-
-
-
-
-
-
-
-
-
-
-Fajardo, et al.           Expires July 24, 2011               [Page 154]
+Fajardo, et al.              Standards Track                  [Page 151]
 
-Internet-Draft           Diameter Base Protocol             January 2011
+RFC 6733                 Diameter Base Protocol             October 2012
 
 
 Authors' Addresses
@@ -8634,7 +8469,7 @@ Authors' Addresses
    USA
 
    Phone: +1-908-421-1845
-   Email: [email protected]
+   EMail: [email protected]
 
 
    Jari Arkko
@@ -8643,7 +8478,7 @@ Authors' Addresses
    Finland
 
    Phone: +358 40 5079256
-   Email: [email protected]
+   EMail: [email protected]
 
 
    John Loughney
@@ -8653,17 +8488,17 @@ Authors' Addresses
    US
 
    Phone: +1-650-283-8068
-   Email: [email protected]
+   EMail: [email protected]
 
 
-   Glenn Zorn
+   Glen Zorn (editor)
    Network Zen
-   1310 East Thomas Street
-   Seattle, WA  98102
-   US
+   227/358 Thanon Sanphawut
+   Bang Na, Bangkok  10260
+   Thailand
 
-   Phone:
-   Email: [email protected]
+   Phone: +66 (0) 87-0404617
+   EMail: [email protected]
 
 
 
@@ -8676,6 +8511,5 @@ Authors' Addresses
 
 
 
-Fajardo, et al.           Expires July 24, 2011               [Page 155]
+Fajardo, et al.              Standards Track                  [Page 152]
 
-
diff --git a/lib/diameter/doc/standard/rfc6737.txt b/lib/diameter/doc/standard/rfc6737.txt
new file mode 100644
index 0000000000..50aa33e98f
--- /dev/null
+++ b/lib/diameter/doc/standard/rfc6737.txt
@@ -0,0 +1,339 @@
+
+
+
+
+
+
+Internet Engineering Task Force (IETF)                           K. Jiao
+Request for Comments: 6737                                        Huawei
+Category: Standards Track                                        G. Zorn
+ISSN: 2070-1721                                              Network Zen
+                                                            October 2012
+
+
+              The Diameter Capabilities Update Application
+
+Abstract
+
+   This document defines a new Diameter application and associated
+   Command Codes.  The Capabilities Update application is intended to
+   allow the dynamic update of certain Diameter peer capabilities while
+   the peer-to-peer connection is in the open state.
+
+Status of This Memo
+
+   This is an Internet Standards Track document.
+
+   This document is a product of the Internet Engineering Task Force
+   (IETF).  It represents the consensus of the IETF community.  It has
+   received public review and has been approved for publication by the
+   Internet Engineering Steering Group (IESG).  Further information on
+   Internet Standards is available in Section 2 of RFC 5741.
+
+   Information about the current status of this document, any errata,
+   and how to provide feedback on it may be obtained at
+   http://www.rfc-editor.org/info/rfc6737.
+
+Copyright Notice
+
+   Copyright (c) 2012 IETF Trust and the persons identified as the
+   document authors.  All rights reserved.
+
+   This document is subject to BCP 78 and the IETF Trust's Legal
+   Provisions Relating to IETF Documents
+   (http://trustee.ietf.org/license-info) in effect on the date of
+   publication of this document.  Please review these documents
+   carefully, as they describe your rights and restrictions with respect
+   to this document.  Code Components extracted from this document must
+   include Simplified BSD License text as described in Section 4.e of
+   the Trust Legal Provisions and are provided without warranty as
+   described in the Simplified BSD License.
+
+
+
+
+
+
+
+Jiao & Zorn                  Standards Track                    [Page 1]
+
+RFC 6737              Diameter Capabilities Update          October 2012
+
+
+Table of Contents
+
+   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
+   2.  Specification of Requirements . . . . . . . . . . . . . . . . . 2
+   3.  Diameter Protocol Considerations  . . . . . . . . . . . . . . . 3
+   4.  Capabilities Update . . . . . . . . . . . . . . . . . . . . . . 3
+     4.1.  Command Code Values . . . . . . . . . . . . . . . . . . . . 4
+       4.1.1.  Capabilities-Update-Request . . . . . . . . . . . . . . 4
+       4.1.2.  Capabilities-Update-Answer  . . . . . . . . . . . . . . 5
+   5.  Security Considerations . . . . . . . . . . . . . . . . . . . . 5
+   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
+     6.1.  Application Identifier  . . . . . . . . . . . . . . . . . . 5
+     6.2.  Command Codes . . . . . . . . . . . . . . . . . . . . . . . 5
+   7.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . 5
+   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 5
+   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 6
+     9.1.  Normative References  . . . . . . . . . . . . . . . . . . . 6
+     9.2.  Informative References  . . . . . . . . . . . . . . . . . . 6
+
+1.  Introduction
+
+   Capabilities exchange is an important component of the Diameter base
+   protocol [RFC6733], allowing peers to exchange identities and
+   Diameter capabilities (protocol version number, supported Diameter
+   applications, security mechanisms, etc.).  As defined in RFC 3588,
+   however, the capabilities exchange process takes place only once, at
+   the inception of a transport connection between a given pair of
+   peers.  Therefore, if a peer's capabilities change (due to a software
+   update, for example), the existing connection(s) must be torn down
+   (along with all of the associated user sessions) and restarted before
+   the modified capabilities can be advertised.
+
+   This document defines a new Diameter application intended to allow
+   the dynamic update of a subset of Diameter peer capabilities over an
+   existing connection.  Because the Capabilities Update application
+   specified herein operates over an existing transport connection,
+   modification of certain capabilities is prohibited.  Specifically,
+   modifying the security mechanism in use is not allowed; if the
+   security method used between a pair of peers is changed, the affected
+   connection MUST be restarted.
+
+2.  Specification of Requirements
+
+   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
+   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
+   document are to be interpreted as described in RFC 2119 [RFC2119].
+
+
+
+
+
+Jiao & Zorn                  Standards Track                    [Page 2]
+
+RFC 6737              Diameter Capabilities Update          October 2012
+
+
+3.  Diameter Protocol Considerations
+
+   This section details the relationship of the Diameter Capabilities
+   Update application to the Diameter base protocol.
+
+   This document specifies Diameter Application-Id 10.  Diameter nodes
+   conforming to this specification MUST advertise support by including
+   the value 10 in the Auth-Application-Id of the Capabilities-Exchange-
+   Request (CER) and Capabilities-Exchange-Answer (CEA) commands
+   [RFC6733].
+
+4.  Capabilities Update
+
+   When the capabilities of a Diameter node conforming to this
+   specification change, the node MUST notify all of the nodes with
+   which it has an open transport connection and which have also
+   advertised support for the Capabilities Update application using the
+   Capabilities-Update-Request (CUR) message (Section 4.1.1).  This
+   message allows the update of a peer's capabilities (supported
+   Diameter applications, etc.).
+
+   A Diameter node only issues a given command to those peers that have
+   advertised support for the Diameter application that defines the
+   command; a Diameter node must cache the supported applications in
+   order to ensure that unrecognized commands and/or Attribute-Value
+   Pairs (AVPs) are not unnecessarily sent to a peer.
+
+   The receiver of the CUR MUST determine common applications by
+   computing the intersection of its own set of supported Application
+   Ids against all of the Application-Id AVPs (Auth-Application-Id,
+   Acct-Application-Id, and Vendor-Specific-Application-Id) present in
+   the CUR.  The value of the Vendor-Id AVP in the Vendor-Specific-
+   Application-Id MUST NOT be used during computation.
+
+   If the receiver of a CUR does not have any applications in common
+   with the sender, then it MUST return a Capabilities-Update-Answer
+   (CUA) (Section 4.1.2) with the Result-Code AVP set to
+   DIAMETER_NO_COMMON_APPLICATION [RFC6733], and it SHOULD disconnect
+   the transport-layer connection.  However, if active sessions are
+   using the connection, peers MAY delay disconnection until the
+   sessions can be redirected or gracefully terminated.  Note that
+   receiving a CUA from a peer advertising itself as a relay (see
+   [RFC6733], Section 2.4) MUST be interpreted as having common
+   applications with the peer.
+
+   As for CER/CEA messages, the CUR and CUA messages MUST NOT be
+   proxied, redirected, or relayed.
+
+
+
+
+Jiao & Zorn                  Standards Track                    [Page 3]
+
+RFC 6737              Diameter Capabilities Update          October 2012
+
+
+   Even though the CUR/CUA messages cannot be proxied, it is still
+   possible for an upstream agent to receive a message for which there
+   are no peers available to handle the application that corresponds to
+   the Command Code.  This could happen if, for example, the peers are
+   too busy or down.  In such instances, the 'E' bit MUST be set in the
+   answer message with the Result-Code AVP set to
+   DIAMETER_UNABLE_TO_DELIVER to inform the downstream peer to take
+   action (e.g., re-routing requests to an alternate peer).
+
+4.1.  Command Code Values
+
+   This section defines Command Code [RFC6733] values that MUST be
+   supported by all Diameter implementations conforming to this
+   specification.  The following Command Codes are defined in this
+   document: Capabilities-Update-Request (CUR, Section 4.1.1), and
+   Capabilities-Update-Answer (CUA, Section 4.1.2).  The Diameter
+   Command Code Format (CCF) ([RFC6733], Section 3.2) is used in the
+   definitions.
+
+4.1.1.  Capabilities-Update-Request
+
+   The Capabilities-Update-Request (CUR), indicated by the Command Code
+   set to 328 and the Command Flags' 'R' bit set, is sent to update
+   local capabilities.  Upon detection of a transport failure, this
+   message MUST NOT be sent to an alternate peer.
+
+   When Diameter is run over the Stream Control Transmission Protocol
+   (SCTP) [RFC4960], which allows connections to span multiple
+   interfaces and multiple IP addresses, the Capabilities-Update-Request
+   message MUST contain one Host-IP-Address AVP for each potential IP
+   address that may be locally used when transmitting Diameter messages.
+
+   Message Format
+
+      <CUR> ::= < Diameter Header: 328, REQ >
+                { Origin-Host }
+                { Origin-Realm }
+             1* { Host-IP-Address }
+                { Vendor-Id }
+                { Product-Name }
+                [ Origin-State-Id ]
+              * [ Supported-Vendor-Id ]
+              * [ Auth-Application-Id ]
+              * [ Acct-Application-Id ]
+              * [ Vendor-Specific-Application-Id ]
+                [ Firmware-Revision ]
+              * [ AVP ]
+
+
+
+
+Jiao & Zorn                  Standards Track                    [Page 4]
+
+RFC 6737              Diameter Capabilities Update          October 2012
+
+
+4.1.2.  Capabilities-Update-Answer
+
+   The Capabilities-Update-Answer, indicated by the Command Code set to
+   328 and the Command Flags' 'R' bit cleared, is sent in response to a
+   CUR message.
+
+                     Message Format
+
+                     <CUA> ::= < Diameter Header: 328 >
+                               { Origin-Host }
+                               { Origin-Realm }
+                               { Result-Code }
+                               [ Error-Message ]
+                             * [ AVP ]
+
+5.  Security Considerations
+
+   The security considerations applicable to the Diameter base protocol
+   [RFC6733] are also applicable to this document.
+
+6.  IANA Considerations
+
+   This section explains the criteria to be used by the IANA for
+   assignment of numbers within namespaces used within this document.
+
+6.1.  Application Identifier
+
+   This specification assigns the value 10 (Diameter Capabilities
+   Update) from the Application Identifiers namespace [RFC6733].  See
+   Section 3 for the assignment of the namespace in this specification.
+
+6.2.  Command Codes
+
+   This specification assigns the value 328 (Capabilities-Update-
+   Request/Capabilities-Update-Answer (CUR/CUA)) from the Command Codes
+   namespace [RFC6733].  See Section 4.1 for the assignment of the
+   namespace in this specification.
+
+7.  Contributors
+
+   This document is based upon work done by Tina Tsou.
+
+8.  Acknowledgements
+
+   Thanks to Sebastien Decugis, Niklas Neumann, Subash Comerica, Lionel
+   Morand, Dan Romascanu, Dan Harkins, and Ravi for helpful review and
+   discussion.
+
+
+
+
+Jiao & Zorn                  Standards Track                    [Page 5]
+
+RFC 6737              Diameter Capabilities Update          October 2012
+
+
+9.  References
+
+9.1.  Normative References
+
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+   [RFC6733]  Fajardo, V., Arkko, J., Loughney, J., and G. Zorn,
+              "Diameter Base Protocol", RFC 6733, October 2012.
+
+9.2.  Informative References
+
+   [RFC4960]  Stewart, R., "Stream Control Transmission Protocol",
+              RFC 4960, September 2007.
+
+Authors' Addresses
+
+   Jiao Kang
+   Huawei Technologies
+   Section F1, Huawei Industrial Base
+   Bantian, Longgang District
+   Shenzhen  518129
+   P.R. China
+
+   EMail: [email protected]
+
+
+   Glen Zorn
+   Network Zen
+   227/358 Thanon Sanphawut
+   Bang Na, Bangkok  10260
+   Thailand
+
+   Phone: +66 (0) 909-201060
+   EMail: [email protected]
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Jiao & Zorn                  Standards Track                    [Page 6]
+