git-svn-id: file:///home/ksmith/gitmigration/svn/xmpp/trunk@2266 4b5297f7-1745-476d-ba37-a9c6900126ab
xep-0352-v0.2
Peter Saint-Andre 2008-09-25 19:43:42 +00:00
parent e09d74a934
commit 79b6b0e61f
1 changed files with 126 additions and 101 deletions

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@ -20,12 +20,25 @@
</dependencies>
<supersedes/>
<supersededby/>
<shortname>TO BE ASSIGNED</shortname>
<shortname>NOT_YET_ASSIGNED</shortname>
&joebeda;
&stpeter;
&scottlu;
&hildjj;
&seanegan;
<revision>
<version>0.10</version>
<date>2008-09-25</date>
<initials>psa</initials>
<remark>
<ul>
<li>Added an ID attribute to the candidate, trying, and received elements for tracking purposes.</li>
<li>Specified that trying and received messages must be sent.</li>
<li>Modified namespaces to incorporate namespace versioning.</li>
<li>Cleaned up XML schemas.</li>
</ul>
</remark>
</revision>
<revision>
<version>0.9</version>
<date>2007-11-27</date>
@ -82,7 +95,8 @@
</revision>
</header>
<section1 topic='Introduction' anchor='intro'>
<p>&xep0166; defines a framework for negotiating and managing out-of-band data sessions over XMPP. In order to provide a flexible framework, the base Jingle specification defines neither data transport methods nor application formats, leaving that up to separate specifications. The current document defines a transport method for establishing and managing data between XMPP entities using a raw User Datagram Protocol (UDP) connection (see &rfc0768;). This "raw-udp" method results in a lossy transport method suitable for use in media applications where some packet loss is tolerable (e.g., audio and video).</p>
<p>&xep0166; defines a framework for negotiating and managing out-of-band data sessions over XMPP. In order to provide a flexible framework, the base Jingle specification defines neither data transport methods nor application formats, leaving that up to separate specifications. The current document defines a transport method for establishing and managing data between XMPP entities using a raw User Datagram Protocol (UDP) "connection" (see &rfc0768;). This "raw-udp" method results in a lossy transport method suitable for use in media applications where some packet loss is tolerable (e.g., audio and video).</p>
<p>Note: The Raw UDP transport does not provide end-to-end traversal of Network Address Translators (NATs); if NAT traversal is needed, Jingle clients SHOULD use &ice; as described in &xep0176;. The Raw UDP transport method is defined only for the purpose of specifying the IP address and port that an entity considers "most likely to succeed" and is a "hit-or-miss" method that might work end-to-end in some circumstances. However, this method can prove useful when the communications architecture includes intermediate gateways or relays, as described in <cite>XEP-0176</cite>.</p>
</section1>
<section1 topic='Requirements' anchor='reqs'>
<p>The Jingle transport method defined herein is designed to meet the following requirements:</p>
@ -91,10 +105,9 @@
<li>Make it relatively easy to implement support in standard Jabber/XMPP clients.</li>
<li>Where communication with non-XMPP entities is needed, push as much complexity as possible onto server-side gateways between the XMPP network and the non-XMPP network.</li>
</ol>
<p>Note: The Raw UDP transport does not provide traversal of Network Address Translators (NATs); if NAT traversal is needed, &xep0176; SHOULD be used. The Raw UDP transport method is defined only for the purpose of specifying the IP address and port that an entity considers "most likely to succeed" and is a "hit-or-miss" method that may work in some circumstances. The method can therefore be thought of as the Jingle equivalent of the "I'm Feeling Lucky" button; it is also helpful for use in unit-testing of Jingle implementation by developers working on a local network (see &xep0208;).</p>
</section1>
<section1 topic='Jingle Conformance' anchor='conformance'>
<p>In accordance with Section 8 of <cite>XEP-0166</cite>, this document specifies the following information related to the Jingle Raw UDP transport type:</p>
<p>In accordance with Section 10 of <cite>XEP-0166</cite>, this document specifies the following information related to the Jingle Raw UDP transport type:</p>
<ol>
<li><p>The transport negotiation process is defined in the <link url='#protocol'>Protocol Description</link> section of this document.</p></li>
<li><p>The semantics of the &TRANSPORT; element are defined in the <link url='#initiate'>Transport Initiation</link> section of this document.</p></li>
@ -104,27 +117,32 @@
</section1>
<section1 topic='Protocol Description' anchor='protocol'>
<section2 topic='Transport Initiation' anchor='initiate'>
<p>In order for the initiator in a Jingle exchange to start the negotiation, it MUST send a Jingle "session-initiate" stanza as described in <cite>XEP-0166</cite>. This stanza MUST include at least one content type. If the initiator wishes to negotiate the Raw UDP transport for a given content type, it MUST include a &TRANSPORT; child element qualified by the 'urn:xmpp:tmp:jingle:transports:raw-udp' namespace &NSNOTE;, which MUST <note>This is required to avoid a round trip and help expedite the negotiation.</note> include the initiator's Raw UDP candidate via the 'ip', 'port', 'generation', and 'name' attributes of the &CANDIDATE; element.</p>
<p>In order for the initiator in a Jingle exchange to start the negotiation, it MUST send a Jingle "session-initiate" stanza as described in <cite>XEP-0166</cite>. This stanza MUST include at least one content type. If the initiator wishes to negotiate the Raw UDP transport for a given content type, it MUST include a &TRANSPORT; child element qualified by the 'urn:xmpp:jingle:transports:raw-udp:0' namespace &VNOTE;, which MUST <note>This is required to avoid a round trip and help expedite the negotiation.</note> include the initiator's Raw UDP candidate via the 'ip', 'port', 'generation', and 'id' attributes of the &CANDIDATE; element.</p>
<example caption="Initiation"><![CDATA[
<iq from='romeo@montague.net/orchard'
id='jingle1'
to='juliet@capulet.com/balcony'
type='set'>
<jingle xmlns='urn:xmpp:tmp:jingle'
<jingle xmlns='urn:xmpp:jingle:0'
action='session-initiate'
initiator='romeo@montague.net/orchard'
sid='a73sjjvkla37jfea'>
<content creator='initiator' name='this-is-the-audio-content'>
<description ...>
<transport xmlns='urn:xmpp:tmp:jingle:transports:raw-udp'>
<candidate ip='10.1.1.104' port='13540' generation='0'/>
<description xmlns='urn:xmpp:jingle:apps:rtp:0' media='audio'>
<payload-type id='18' name='G729'/>
</description>
<transport xmlns='urn:xmpp:jingle:transports:raw-udp:0'>
<candidate generation='0'
id='a9j3mnbtu1'
ip='10.1.1.104'
port='13540'/>
</transport>
</content>
</jingle>
</iq>
]]></example>
<p>The 'generation', 'ip', and 'port' attributes are REQUIRED. The 'ip' and 'port' attributes are self-explanatory. The 'generation' attribute provides a tracking mechanism for determining which version of this candidate is in force (this is useful if the candidate is redefined mid-stream, for example if the port is changed).</p>
<p>Note: The "Raw UDP candidate" is the candidate that the entity has reason to believe will be most likely to succeed for that content type, and thus is equivalent to the "default" candidate as described in Section 4.1.3 of &ice;. This is not necessarily the entity's preferred address for communication, but instead is the "address most likely to succeed", i.e., the address that is assumed to be reachable by the vast majority of target entities. To determine reachability, the client needs classify ahead of time the permissiveness of the NAT or firewall it is behind, if any. It then SHOULD assign the Raw UDP candidate as follows, where the candidate types are as described in <cite>ICE</cite>:</p>
<p>Note: The "Raw UDP candidate" is the candidate that the entity has reason to believe will be most likely to succeed for that content type, and thus is equivalent to the "default" candidate as described in &ice;. This is not necessarily the entity's preferred address for communication, but instead is the "address most likely to succeed", i.e., the address that is assumed to be reachable by the vast majority of target entities. To determine reachability, the sender needs to classify ahead of time the permissiveness of the NAT or firewall it is behind, if any. It then SHOULD assign the Raw UDP candidate as follows, where the candidate types are as described in <cite>ICE</cite>:</p>
<table caption='Raw UDP Candidate Assignment'>
<tr>
<th>NAT Type</th>
@ -153,14 +171,58 @@
type='result'/>
]]></example>
<p>Once the responder acknowledges the session initiation request, it:</p>
<ul>
<ol>
<li>MUST attempt to send media data via UDP to the IP and port specified in the initiator's Raw UDP candidate.</li>
<li>MUST send an informational message of &lt;trying/&gt;.</li>
<li>SHOULD send its own Raw UDP candidate to the initiator via a Jingle "transport-info" message.</li>
<li>SHOULD send an informational message of &lt;trying/&gt;.</li>
</ul>
<p>These are done simultaneously in order to ensure that a connection can be made, since the initiator's Raw UDP candidate may not result in success.</p>
</ol>
<p>These are done simultaneously in order to ensure that a connection can be made, since the initiator's Raw UDP candidate might not result in success.</p>
<section3 topic='Sending Media' anchor='response-send'>
<p>The responder MUST immediately attempt to send data to the IP and port specified in the initiation request. If all goes well, the data will be received by the initiator and media will flow. Because delivery of UDP data is not acknowledged, a party that receives media SHOULD send an informational message of &lt;received/&gt; to the other party as specified below.</p>
<p>The responder MUST immediately attempt to send data to the IP and port specified in the initiation request. If all goes well, the data will be received by the initiator and media will flow. Because delivery of UDP data is not acknowledged, a party that receives media MUST send an informational message of &lt;received/&gt; to the other party as specified below.</p>
</section3>
<section3 topic='Sending an Informational Message' anchor='response-info'>
<p>When it attempts to send data to a Raw UDP candidate, a party MUST send an informational message of &lt;trying/&gt;, including the candidate ID for tracking purposes.</p>
<example caption="Responder sends trying message"><![CDATA[
<iq from='juliet@capulet.com/balcony'
id='trying1'
to='romeo@montague.net/orchard'
type='set'>
<jingle xmlns='urn:xmpp:jingle:0'
action='session-info'
initiator='romeo@montague.net/orchard'
sid='a73sjjvkla37jfea'>
<trying xmlns='urn:xmpp:jingle:transports:raw-udp:info:0'
id='a9j3mnbtu1'/>
</jingle>
</iq>
]]></example>
<example caption="Initiator acknowledges trying message"><![CDATA[
<iq from='romeo@montague.lit/orchard'
id='trying1'
to='juliet@capulet.lit/balcony'
type='result'/>
]]></example>
<p>If a party receives data, it MUST send an informational message of &lt;received/&gt;, including the candidate ID for tracking purposes.</p>
<example caption="Initiator sends received message"><![CDATA[
<iq from='romeo@montague.net/orchard'
id='received1'
to='juliet@capulet.com/balcony'
type='set'>
<jingle xmlns='urn:xmpp:jingle:0'
action='session-info'
initiator='romeo@montague.net/orchard'
sid='a73sjjvkla37jfea'>
<received xmlns='urn:xmpp:jingle:transports:raw-udp:info:0'
id='a9j3mnbtu1'/>
</jingle>
</iq>
]]></example>
<example caption="Responder acknowledges received message"><![CDATA[
<iq from='juliet@capulet.lit/balcony'
id='received1'
to='romeo@montague.lit/orchard'
type='result'/>
]]></example>
</section3>
<section3 topic='Sending A Candidate' anchor='response-candidate'>
<p>As noted, the responder SHOULD send its own Raw UDP candidate to the initiator by sending a transport-info message to the initiator, as shown in the following example.</p>
@ -169,13 +231,16 @@
id='jingle2'
to='romeo@montague.net/orchard'
type='set'>
<jingle xmlns='urn:xmpp:tmp:jingle'
<jingle xmlns='urn:xmpp:jingle:0'
action='transport-info'
initiator='romeo@montague.net/orchard'
sid='a73sjjvkla37jfea'>
<content creator='initiator' name='this-is-the-audio-content'>
<transport xmlns='urn:xmpp:tmp:jingle:transports:raw-udp'>
<candidate ip='208.245.212.67' port='9876' generation='0'/>
<transport xmlns='urn:xmpp:jingle:transports:raw-udp:0'>
<candidate generation='0'
id='z7sdjb01hf'
ip='208.68.163.214'
port='9876'/>
</transport>
</content>
</jingle>
@ -188,54 +253,12 @@
to='juliet@capulet.com/balcony'
type='result'/>
]]></example>
<p>Naturally, the initiator SHOULD also attempt to send media to the responder as specified above. This media, too, may or may not get through, but if it does then the other party SHOULD acknowledge receipt.</p>
</section3>
<section3 topic='Sending An Informational Message' anchor='response-info'>
<p>When it attempts to send data to a Raw UDP candidate, a party SHOULD send an informational message of &lt;trying/&gt;.</p>
<example caption="Responder sends trying message"><![CDATA[
<iq from='juliet@capulet.com/balcony'
id='trying1'
to='romeo@montague.net/orchard'
type='set'>
<jingle xmlns='urn:xmpp:tmp:jingle'
action='session-info'
initiator='romeo@montague.net/orchard'
sid='a73sjjvkla37jfea'>
<trying xmlns='urn:xmpp:tmp:jingle:transports:raw-udp:info'/>
</jingle>
</iq>
]]></example>
<example caption="Initiator acknowledges trying message"><![CDATA[
<iq from='romeo@montague.lit/orchard'
id='trying1'
to='juliet@capulet.lit/balcony'
type='result'/>
]]></example>
<p>If a party receives data, it SHOULD send an informational message of &lt;received/&gt;.</p>
<example caption="Initiator sends received message"><![CDATA[
<iq from='romeo@montague.net/orchard'
id='received1'
to='juliet@capulet.com/balcony'
type='set'>
<jingle xmlns='urn:xmpp:tmp:jingle'
action='session-info'
initiator='romeo@montague.net/orchard'
sid='a73sjjvkla37jfea'>
<received xmlns='urn:xmpp:tmp:jingle:transports:raw-udp:info'/>
</jingle>
</iq>
]]></example>
<example caption="Responder acknowledges received message"><![CDATA[
<iq from='juliet@capulet.lit/balcony'
id='received1'
to='romeo@montague.lit/orchard'
type='result'/>
]]></example>
<p>Naturally, the initiator SHOULD also attempt to send media to the responder as specified above. This media, too, might or might not get through, but if it does then the other party MUST acknowledge success by sending a &lt;received/&gt; message.</p>
</section3>
</section2>
<section2 topic='Informational Messages' anchor='protocol-info'>
<p>Informational messages MAY be sent by either party within the context of the Raw UDP transport to communicate whether the party has attempted to send media or has received media. The informational message MUST be an IQ-set containing a &JINGLE; element of type "session-info", where the informational message is a payload element qualified by the 'urn:xmpp:tmp:jingle:transports:raw-udp:info' namespace &NSNOTE;. The following payload elements are defined:</p>
<p>Informational messages are sent within the context of the Raw UDP transport to communicate whether the party has attempted to send media or has received media. The informational message MUST be an IQ-set containing a &JINGLE; element of type "session-info", where the informational message is a payload element qualified by the 'urn:xmpp:jingle:transports:raw-udp:info:0' namespace &VNOTE;. The following payload elements are defined:</p>
<table caption='Information Payload Elements'>
<tr>
<th>Element</th>
@ -255,7 +278,7 @@
</section1>
<section1 topic='Determining Support' anchor='support'>
<p>If an entity supports the Jingle Raw UDP transport, it MUST return a feature of "urn:xmpp:tmp:jingle:transports:raw-udp" &NSNOTE; in response to &xep0030; information requests.</p>
<p>If an entity supports the Jingle Raw UDP transport, it MUST return a feature of "urn:xmpp:jingle:transports:raw-udp:0" &VNOTE; in response to &xep0030; information requests.</p>
<example caption="Service discovery information request"><![CDATA[
<iq from='romeo@montague.net/orchard'
id='disco1'
@ -271,16 +294,16 @@
type='result'>
<query xmlns='http://jabber.org/protocol/disco#info'>
...
<feature var='urn:xmpp:tmp:jingle:transports:raw-udp'/>
<feature var='urn:xmpp:jingle:transports:raw-udp:0'/>
...
</query>
</iq>
]]></example>
<p>Naturally, support MAY also be determined via the dynamic, presence-based profile of Service Discovery defined in &xep0115;.</p>
<p>In order for an application to determine whether an entity supports this protocol, where possible it SHOULD use the dynamic, presence-based profile of service discovery defined in &xep0115;. However, if an application has not received entity capabilities information from an entity, it SHOULD use explicit service discovery instead.</p>
</section1>
<section1 topic='Security Considerations' anchor='security'>
<p>In order to secure the data stream that is negotiated via the Jingle ICE-UDP transport, implementations SHOULD use encryption methods appropriate to the transport method and media being exchanged (for details regarding audio and video exchanges via RTP, refer to <cite>XEP-0167</cite> and <cite>XEP-0180</cite>).</p>
<p>In order to secure the data stream that is negotiated via the Jingle ICE-UDP transport, implementations SHOULD use encryption methods appropriate to the transport method and media being exchanged (for details regarding RTP sessions, refer to &xep0167;).</p>
</section1>
<section1 topic='IANA Considerations' anchor='iana'>
@ -288,27 +311,25 @@
</section1>
<section1 topic='XMPP Registrar Considerations' anchor='registrar'>
<section2 topic='Protocol Namespaces' anchor='ns'>
<p>Until this specification advances to a status of Draft, its associated namespaces shall be:</p>
<section2 topic='Protocol Namespaces' anchor='registrar-ns'>
<p>This specification defines the following XML namespaces:</p>
<ul>
<li>urn:xmpp:tmp:jingle:transports:raw-udp</li>
<li>urn:xmpp:tmp:jingle:transports:raw-udp:info</li>
</ul>
<p>Upon advancement of this specification, the &REGISTRAR; shall issue permanent namespaces in accordance with the process defined in Section 4 of &xep0053;.</p>
<p>The following namespaces are requested, and are thought to be unique per the XMPP Registrar's requirements:</p>
<ul>
<li>urn:xmpp:jingle:transport:raw-udp</li>
<li>urn:xmpp:jingle:transport:raw-udp:info</li>
<li>urn:xmpp:jingle:transports:raw-udp:0</li>
<li>urn:xmpp:jingle:transports:raw-udp:info:0</li>
</ul>
<p>Upon advancement of this specification from a status of Experimental to a status of Draft, the &REGISTRAR; shall add the foregoing namespaces to the registry located at &NAMESPACES;, as described in Section 4 of &xep0053;.</p>
</section2>
<section2 topic='Protocol Versioning' anchor='registrar-versioning'>
<p>If the protocol defined in this specification undergoes a major revision that is not fully backward-compatible with an older version, or that contains significant new features, the XMPP Registrar shall increment the protocol version number found at the end of the XML namespaces defined herein, as described in Section 4 of <cite>XEP-0053</cite>.</p>
</section2>
<section2 topic='Jingle Transport Methods' anchor='registrar-transports'>
<p>The XMPP Registrar shall include "raw-udp" in its registry of Jingle transport methods. The registry submission is as follows:</p>
<code><![CDATA[
<transport>
<name>raw-udp</name>
<desc>A method for exchanging data over a raw UDP connection.</desc>
<desc>A method for exchanging data over raw UDP datagrams.</desc>
<type>lossy</type>
<doc>XEP-0176</doc>
<doc>XEP-0177</doc>
</transport>
]]></code>
</section2>
@ -321,29 +342,31 @@
<xs:schema
xmlns:xs='http://www.w3.org/2001/XMLSchema'
targetNamespace='urn:xmpp:tmp:jingle:transports:raw-udp'
xmlns='urn:xmpp:tmp:jingle:transports:raw-udp'
targetNamespace='urn:xmpp:jingle:transports:raw-udp:0'
xmlns='urn:xmpp:jingle:transports:raw-udp:0'
elementFormDefault='qualified'>
<xs:element name='transport'>
<xs:complexType>
<xs:sequence>
<xs:element ref='candidate' minOccurs='0' maxOccurs='1'/>
<xs:element name='candidate'
type='candidateElementType'
minOccurs='0'
maxOccurs='1'/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name='candidate'>
<xs:complexType>
<xs:simpleContent>
<xs:extension base='empty'>
<xs:attribute name='generation' type='xs:unsignedByte' use='required'/>
<xs:attribute name='ip' type='xs:string' use='required'/>
<xs:attribute name='port' type='xs:unsignedShort' use='required'/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
<xs:complexType name='candidateElementType'>
<xs:simpleContent>
<xs:extension base='empty'>
<xs:attribute name='generation' type='xs:unsignedByte' use='required'/>
<xs:attribute name='id' type='xs:NCName' use='required'/>
<xs:attribute name='ip' type='xs:string' use='required'/>
<xs:attribute name='port' type='xs:unsignedShort' use='required'/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:simpleType name='empty'>
<xs:restriction base='xs:string'>
@ -360,19 +383,21 @@
<xs:schema
xmlns:xs='http://www.w3.org/2001/XMLSchema'
targetNamespace='urn:xmpp:tmp:jingle:transports:raw-udp:info'
xmlns='urn:xmpp:tmp:jingle:transports:raw-udp:info'
targetNamespace='urn:xmpp:jingle:transports:raw-udp:info:0'
xmlns='urn:xmpp:jingle:transports:raw-udp:info:0'
elementFormDefault='qualified'>
<xs:element name='received' type='empty'/>
<xs:element name='received' type='infoElementType'/>
<xs:element name='trying' type='empty'/>
<xs:element name='trying' type='infoElementType'/>
<xs:simpleType name='empty'>
<xs:restriction base='xs:string'>
<xs:enumeration value=''/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name='infoElementType'>
<xs:simpleContent>
<xs:extension base='empty'>
<xs:attribute name='id' type='xs:NCName' use='required'/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:schema>
]]></code>