xeps/inbox/cs-2021.xml

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<!ENTITY component "<note>Support can be enabled via an external component or an internal server module/plugin. If claiming compliance using such an addition, the necessary components/modules/plugins MUST be detailed.</note>">
<!ENTITY usecases "<note>Support for the Entity Use Cases and Occupant Use Cases is REQUIRED; support for the remaining use cases is RECOMMENDED.</note>">
<!ENTITY onlyone "<note>Only one of the recommended providers must be implemented for compliance.</note>">
<!ENTITY nocli "<note>Not required for command line or terminal based interfaces.</note>">
<!ENTITY avatar "<note>While 'User Avatars' is more modern, 'vCard-Based Avatars' is more widely deployed. Although it is suggested that to maximise interoperability with existing software a client fully supports both it is sufficient to claim compliance with this suite if the support for 'vCard-Based Avatars' is read-only.</note>">
<!ENTITY pubsubjid "<note>While 'Personal Eventing Protocol' does not require all the features of 'Publish-Subscribe' to be available on the users' JIDs, and nor does this suite, it is desirable for this to be the case and it is expected that this will a requirement of future Compliance Suites.</note>">
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<xep>
  <header>
    <title>XMPP Compliance Suites 2021</title>
    <abstract>
      This document defines XMPP application categories for different use cases
      (Core, Web, IM, and Mobile), and specifies the required XEPs that client and
      server software needs to implement for compliance with the use cases.
    </abstract>
    &LEGALNOTICE;
    <number>XXXX</number>
    <status>ProtoXEP</status>
    <type>Standards Track</type>
    <sig>Standards</sig>
    <dependencies>
      <spec>RFC 6120</spec>
      <spec>RFC 6121</spec>
      <spec>RFC 7395</spec>
      <spec>RFC 7590</spec>
      <spec>RFC 7622</spec>
      <spec>XEP-0030</spec>
      <spec>XEP-0045</spec>
      <spec>XEP-0048</spec>
      <spec>XEP-0049</spec>
      <spec>XEP-0084</spec>
      <spec>XEP-0085</spec>
      <spec>XEP-0114</spec>
      <spec>XEP-0115</spec>
      <spec>XEP-0124</spec>
      <spec>XEP-0163</spec>
      <spec>XEP-0191</spec>
      <spec>XEP-0198</spec>
      <spec>XEP-0206</spec>
      <spec>XEP-0223</spec>
      <spec>XEP-0249</spec>
      <spec>XEP-0280</spec>
      <spec>XEP-0313</spec>
      <spec>XEP-0352</spec>
      <spec>XEP-0368</spec>
    </dependencies>
    <supersedes>
      <spec>XEP-0423</spec>
    </supersedes>
    <supersededby/>
    <shortname>CS2021</shortname>
    <author>
      <firstname>Georg</firstname>
      <surname>Lukas</surname>
      <email>georg@op-co.de</email>
      <jid>georg@yax.im</jid>
    </author>
    <revision>
      <version>0.0.1</version>
      <date>2020-09-02</date>
      <initials>gl</initials>
      <remark>
        <p>First draft based on XEP-0423.</p>
      </remark>
    </revision>
  </header>
  <section1 topic='Introduction' anchor='intro'>
    <p>
      There is a growing number of XMPP Extension Protocols (XEPs) that provide
      different building blocks for XMPP-based applications. XMPP software
      developers are confronted with the challenge of finding the right
      combination of XEPs for a given application profile. Users need a way to
      compare applications without resorting to comparing for individual XEP
      numbers.
    </p>
    <p>
      This document defines XMPP application <strong>Categories</strong> based on
      typical use cases (Core, Web, IM, Mobile) and <strong>Levels</strong>
      (Core, Advanced) based on functionality in the respective category. For
      each combination of those, the required XEPs are referenced. As the
      protocol landscape changes over time, this document is updated roughly
      once a year.
    </p>
    <p>
      For developers, this document provides guidance on which specifications
      they need to consider when implementing an application of a certain kind.
      By completing a compliance test or performing a self-assessment, they can
      advertise their implementation as compliant with a given Category and
      Level.
    </p>
    <p>
      For users, this provides an easy way to compare implementations based on
      their respective advertised compliance levels and year.
    </p>
    <p>
      Unless explicitly noted, support for the listed specifications is REQUIRED
      for compliance purposes.
      A feature is considered supported if all comma separated feature providers
      listed in the "Providers" column are implemented (unless otherwise noted).
    </p>
    <section2 topic='Changes since 2020' anchor='changes-2020'>
      <p>The following changes were made to the Compliance Suites since &xep0423;:</p>
      <ul>
	<li>TODO</li>
      </ul>
    </section2>
    <section2 topic='Changes since 2019' anchor='changes'>
      <p>The following changes were made to the Compliance Suites since &xep0412;:</p>
      <ul>
	<li>IM Category:
	  <ul>
	    <li>Core Client: added &xep0245;</li>
	    <li>Core Client and Server: added &xep0363;</li>
	    <li>Advanced Client: added &xep0234;, &xep0261;</li>
	    <li>Advanced Client and Server: added &xep0411;</li>
	    <li>Specifications of note: added &xep0077; and &xep0157;, &xep0392;, &xep0066; and &xep0385;</li>
	  </ul>
	</li>
	<li>Mobile Category:
	  <ul>
	    <li>Specifications of note: added &xep0286;</li>
	  </ul>
	</li>
	<li>Web Category:
	  <ul>
	    <li>Advanced Web: added &xep0156;</li>
	  </ul>
	</li>
      </ul>
    </section2>
  </section1>
  <section1 topic='Compliance Categories' anchor='categories'>
    <section2 topic='Core Compliance Suite' anchor='core'>
      <table caption='XMPP Core Compliance Levels'>
        <tr>
          <th>Feature</th>
          <th>Core Server</th>
          <th>Core Client</th>
          <th>Advanced Server</th>
          <th>Advanced Client</th>
          <th>Providers</th>
        </tr>
        <tr>
          <td><strong>Core features</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&rfc6120; <note>&rfc7622; is not listed due to the unclear interoperability impact of using PRECIS and Stringprep in the same ecosystem.</note></td>
        </tr>
        <tr>
          <td><strong>TLS</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&rfc7590;</td>
        </tr>
        <tr>
          <td><strong>Direct TLS</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;<note>Server support of XEP-0368 means having the ability to accept direct TLS connections.</note></td>
          <td align='center'>&yes;</td>
          <td>&xep0368;</td>
        </tr>
        <tr>
          <td><strong>Feature discovery</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0030;</td>
        </tr>
        <tr>
          <td><strong>Feature broadcasts</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0115;</td>
        </tr>
        <tr>
          <td><strong>Server Extensibility</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td align='center'>N/A</td>
          <td>&xep0114;</td>
        </tr>
        <tr>
          <td><strong>Event publishing</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;&pubsubjid;</td>
          <td align='center'>&yes;</td>
          <td>&xep0163;</td>
        </tr>
      </table>
    </section2>
    <section2 topic='Web Compliance Suite' anchor='web'>
      <p>
        To be considered XMPP web compliant, all features from the core
        compliance category must be met, as well as all features in this suite.
      </p>
      <table caption='XMPP Web Compliance Levels'>
        <tr>
          <th>Feature</th>
          <th>Core Server</th>
          <th>Core Client</th>
          <th>Advanced Server</th>
          <th>Advanced Client</th>
          <th>Providers</th>
        </tr>
        <tr>
          <td><strong>Web Connection Mechanisms</strong></td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;&onlyone;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;&onlyone;</td>
          <td>&rfc7395;, &xep0206; (See also: &xep0124;)</td>
        </tr>
        <tr>
          <td><strong>Connection Mechanism Discovery</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
	  <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td>&xep0156;</td>
        </tr>
      </table>
    </section2>
    <section2 topic='IM Compliance Suite' anchor='im'>
      <p>
        To be considered XMPP IM compliant, all features from the core
        compliance category must be met, as well as all features in this suite.
      </p>
      <table caption='XMPP IM Compliance Levels'>
        <tr>
          <th>Feature</th>
          <th>Core Server</th>
          <th>Core Client</th>
          <th>Advanced Server</th>
          <th>Advanced Client</th>
          <th>Providers</th>
        </tr>
        <tr>
          <td><strong>Core features</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&rfc6121;</td>
        </tr>
        <tr>
	  <td><strong>The /me Command</strong></td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td>&xep0245;</td>
        </tr>
        <tr>
          <td><strong>User Avatars</strong></td>
          <td align='center'>N/A</td>
          <td align='center'>&no;</td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;&nocli;</td>
          <td>&xep0084;</td>
        </tr>
        <tr>
          <td><strong>User Avatar Compatibility</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;&nocli;</td>
          <td>&xep0398;, &xep0153;</td>
        </tr>
        <tr>
          <td><strong>vcard-temp</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0054;</td>
        </tr>
        <tr>
          <td><strong>Outbound Message Synchronization</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0280;</td>
        </tr>
        <tr>
          <td><strong>User Blocking</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0191;</td>
        </tr>
        <tr>
          <td><strong>Group Chat</strong></td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;&usecases;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;&usecases;</td>
          <td>&xep0045;<note>Implementations should take note that future versions of these compliance suites may rely on &xep0369; instead.</note>, &xep0249;</td>
        </tr>
        <tr>
          <td><strong>Advanced Group Chat</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;</td>
	  <td>&xep0048;, &xep0313;<note>Support for requesting history from a MUC archive as opposed to from the user's account.</note>, &xep0410;, &xep0411;</td>
        </tr>
        <tr>
          <td><strong>Persistent Storage of Private Data via PubSub</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;</td>
          <td>&xep0223;</td>
        </tr>
        <tr>
          <td><strong>Private XML Storage</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;</td>
          <td>&xep0049; (only recommended for legacy bookmarks support)</td>
        </tr>
        <tr>
          <td><strong>Stream Management</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0198;</td>
        </tr>
        <tr>
          <td><strong>Message Acknowledgements</strong></td>
          <td align='center'>N/A</td>
          <td align='center'>&no;</td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td>&xep0184;</td>
        </tr>
        <tr>
          <td><strong>History Storage / Retrieval</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0313;</td>
        </tr>
        <tr>
          <td><strong>Chat States</strong></td>
          <td align='center'>N/A</td>
          <td align='center'>&no;</td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td>&xep0085;</td>
        </tr>
        <tr>
          <td><strong>Message Correction</strong></td>
          <td align='center'>N/A</td>
          <td align='center'>&no;</td>
          <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td>&xep0308;</td>
        </tr>
        <tr>
          <td><strong>File Upload</strong></td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;</td>
          <td>&xep0363;</td>
        </tr>
        <tr>
          <td><strong>Direct File Transfer</strong></td>
	  <td align='center'>N/A</td>
          <td align='center'>&no;</td>
	  <td align='center'>N/A</td>
          <td align='center'>&yes;</td>
          <td>&xep0234;, &xep0261;</td>
        </tr>
      </table>
      <p>
	Further specifications of note, which are not required for compliance:
      </p>
      <ul>
	<li>For public IM networks: &xep0077; (should be supported, but not enabled in default server configurations) and &xep0157;</li>
	<li>File uploads should be indicated using &xep0066;, optionally also using &xep0385;</li>
	<li>&xep0392; for cross-client consistency of user names</li>
      </ul>
    </section2>
    <section2 topic='Mobile Compliance Suite' anchor='mobile'>
      <p>
        To be considered XMPP mobile compliant, all features from the core
        compliance category must be met, as well as all features in this suite.
      </p>
      <table caption='XMPP Mobile Compliance Levels'>
        <tr>
          <th>Feature</th>
          <th>Core Server</th>
          <th>Core Client</th>
          <th>Advanced Server</th>
          <th>Advanced Client</th>
          <th>Providers</th>
        </tr>
        <tr>
          <td><strong>Stream Management</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0198;</td>
        </tr>
        <tr>
          <td><strong>Client State Indication</strong></td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td align='center'>&yes;</td>
          <td>&xep0352;</td>
        </tr>
        <tr>
          <td><strong>Third Party Push Notifications</strong></td>
          <td align='center'>&no;</td>
          <td align='center'>&no;</td>
          <td align='center'>&yes;&component;</td>
          <td align='center'>&yes;<note>Only on platforms that disallow long-lasting background connections.</note></td>
          <td>&xep0357;</td>
        </tr>
      </table>
      <p>
	Further specifications of note, which are not required for compliance:
      </p>
      <ul>
	<li>&xep0286;</li>
      </ul>
    </section2>
  </section1>
  <section1 topic='Future Development' anchor='future'>
    <p>This section outlines the protocol specifications that are relevant for
      developers, but are not ready yet to be required for Compliance.
      Developers are encouraged to implement those and
      to share their experience and feedback.</p>
    <ul>
      <li>Client connection optimizations: &xep0386; and &xep0409;, maybe also &xep0397;</li>
      <li>&xep0333;</li>
      <li>&xep0369;</li>
      <li>End-to-End Encryption (E2EE): &xep0380; for tagging encrypted messages, &xep0420; to protect all payloads; and also one or multiple of the following for actual encryption:
	<ul>
	  <li>&xep0384; and &xep0396;</li>
	  <li>&xep0374;</li>
	</ul>
      </li>
      <li>&xep0402; to phase out &xep0048;, &xep0049;, and &xep0411;</li>
      <li>&xep0225; to phase out &xep0114;</li>
      <li>&xep0390; to phase out &xep0115;</li>
    </ul>
  </section1>
  <section1 topic='Implementation Notes' anchor='impl'>
    <p>
      Some of the protocol specifications referenced herein have their own
      dependencies; developers need to consult the relevant specifications for
      further information.
    </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'>
    <p>This document requires no interaction with the &REGISTRAR;.</p>
  </section1>
<section1 topic='Acknowledgements' anchor='ack'>
  <p>
    The author would like to thank Guus der Kinderen, Dele Olajide, Marc
    Laporte, Dave Cridland, Daniel Gultsch, Florian Schmaus, Tobias Markmann,
    and Jonas Schäfer for their suggestions.
  </p>
</section1>
</xep>