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<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE xep SYSTEM 'xep.dtd' [
<!ENTITY % ents SYSTEM 'xep.ent'>
%ents;
]>
<?xml-stylesheet type='text/xsl' href='xep.xsl'?>
<xep>
<header>
<title>Jingle Grouping Framework</title>
<abstract>This specification provides an XML mapping for translating the RFC 5888 SDP Grouping Framework to Jingle</abstract>
&LEGALNOTICE;
<number>0338</number>
<status>Draft</status>
<lastcall>2020-06-30</lastcall>
<type>Standards Track</type>
<sig>Standards</sig>
<approver>Council</approver>
<dependencies>
<spec>XEP-0166</spec>
</dependencies>
<supersedes/>
<supersededby/>
<shortname>NOT_YET_ASSIGNED</shortname>
&fippo;
<revision>
<version>1.0.0</version>
<date>2020-07-21</date>
<initials>XEP Editor (jsc)</initials>
<remark>Advance to Draft as per Council vote from 2020-07-01</remark>
</revision>
<revision>
<version>0.2</version>
<date>2017-09-11</date>
<initials>XEP Editor (jwi)</initials>
<remark>Defer due to lack of activity.</remark>
</revision>
<revision>
<version>0.1</version>
<date>2014-01-08</date>
<initials>psa</initials>
<remark><p>Initial published version approved by the XMPP Council.</p></remark>
</revision>
<revision>
<version>0.0.1</version>
<date>2013-11-25</date>
<initials>ph</initials>
<remark><p>First draft.</p></remark>
</revision>
</header>
<section1 topic="Introduction" anchor="intro">
<p>&rfc5888; defines a framework to group SDP 'm' lines for different purposes. A mapping to Jingle as an extension to &xep0166; is defined in this document.</p>
<p>It is anticipated that the primary use of this is with the &bundle; framework used in WebRTC.</p>
</section1>
<section1 topic='Mapping to Session Description Protocol' anchor='sdp'>
<p>The SDP format defined in <cite>RFC 5888</cite> is shown below.</p>
<code>
a=group:semantics identification-tag
</code>
<p>An example follows.</p>
<code>
a=group:LS voice webcam
</code>
<p>This SDP attribute is translated to Jingle as a &lt;group/&gt; element qualified by the 'urn:xmpp:jingle:apps:grouping:0' namespace, as shown below. The semantics is mapped to a 'semantics' attribute. The identification-tags are mapped to content elements whose name attribute is set to the identification-tag.</p>
<code><![CDATA[
<group xmlns='urn:xmpp:jingle:apps:grouping:0' semantics='semantics'>
<content name='identification-tag 1'/>
<content name='identification-tag 2'/>
</group>
]]></code>
<p>An example follows.</p>
<code><![CDATA[
<group xmlns='urn:xmpp:jingle:apps:grouping:0' semantics='LS'>
<content name='voice'/>
<content name='webcam'/>
</group>
]]></code>
<p>The &lt;group/&gt; element is included as child of the &lt;jingle/&gt; element.</p>
<code><![CDATA[
<iq from='romeo@montague.lit/orchard'
id='rg6s5134'
to='juliet@capulet.lit/balcony'
type='set'>
<jingle xmlns='urn:xmpp:jingle:1'
action='session-initiate'
initiator='romeo@montague.lit/orchard'
sid='a73sjjvkla37jfea'>
<group xmlns='urn:xmpp:jingle:apps:grouping:0' semantics='BUNDLE'>
<content name='voice'/>
<content name='webcam'/>
</group>
<content creator='initiator' name='voice'>
[ ... ]
</content>
<content creator='initiator' name='webcam'>
[ ... ]
</content>
</jingle>
</iq>
]]></code>
<p>Note: the identification-tags correspond to the &lt;content/&gt; 'name' attributes. These in turn map to the 'mid' attribute in SDP.</p>
</section1>
<section1 topic='Determining Support' anchor='disco'>
<p>If an entity supports the grouping framework described in <cite>RFC 5888</cite>, it MUST advertise that fact in its responses to &xep0030; information ("disco#info") requests by returning a feature of 'urn:ietf:rfc:5888':</p>
<example caption='A disco#info query'><![CDATA[
<iq type='get'
from='calvin@usrobots.lit/lab'
to='herbie@usrobots.lit/home'
id='disco1'>
<query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>
]]></example>
<example caption='A disco#info response'><![CDATA[
<iq type='result'
from='herbie@usrobots.lit/home'
to='calvin@usrobots.lit/lab'
id='disco1'>
<query xmlns='http://jabber.org/protocol/disco#info'>
<feature var='urn:xmpp:jingle:1'/>
<feature var='urn:ietf:rfc:5888'/>
</query>
</iq>
]]></example>
<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='Acknowledgements' anchor='acks'>
<p>Thanks to Emil Ivov and Lance Stout for their feedback.</p>
<p>The XML format for this specification originates from <cite>libjingle</cite><note>libjingle is now part of the WebRTC Native Code Package available from <link url='http://webrtc.org'>webrtc.org</link>.</note>.</p>
</section1>
<section1 topic='Security Considerations' anchor='security'>
<p>This document introduces no additional security considerations above and beyond those defined in the documents on which it depends.</p>
</section1>
<section1 topic='IANA Considerations' anchor='iana'>
<p>This document requires no interaction with &IANA;.</p>
</section1>
<section1 topic='XMPP Registrar Considerations' anchor='registrar'>
<section2 topic='Protocol Namespaces' anchor='registrar-ns'>
<p>This specification defines the following XML namespace:</p>
<ul>
<li>urn:xmpp:jingle:apps:grouping:0</li>
</ul>
<p>The &REGISTRAR; includes the foregoing namespace to the registry located at &NAMESPACES;, as described in Section 4 of &xep0053;.</p>
</section2>
<section2 topic='Protocol Versioning' anchor='registrar-versioning'>
&NSVER;
</section2>
</section1>
<section1 topic='XML Schema' anchor='schema'>
<p>TODO</p>
</section1>
</xep>