xeps/xep-0157.xml

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<xep>
<header>
  <title>Contact Addresses for XMPP Services</title>
  <abstract>This document defines a method for specifying contact addresses related to an XMPP service.</abstract>
  &LEGALNOTICE;
  <number>0157</number>
  <status>Proposed</status>
  <type>Informational</type>
  <sig>Standards</sig>
  <approver>Council</approver>
  <dependencies>
    <spec>XMPP Core</spec>
  </dependencies>
  <supersedes/>
  <supersededby/>
  <shortname>N/A</shortname>
  &stpeter;
  <author>
    <firstname>Jacek</firstname>
    <surname>Konieczny</surname>
    <email>jajcus@jajcus.net</email>
    <jid>jajcus@jabber.bnet.pl</jid>
  </author>
  <revision>
    <version>0.5</version>
    <date>2007-01-06</date>
    <initials>psa</initials>
    <remark><p>Changed XMPP address from domain.tld/admin to xmpp@domain.tld.</p></remark>
  </revision>
  <revision>
    <version>0.4</version>
    <date>2007-01-05</date>
    <initials>psa</initials>
    <remark><p>Changed XMPP address from domain.tld to domain.tld/admin to prevent overloading.</p></remark>
  </revision>
  <revision>
    <version>0.3</version>
    <date>2006-07-31</date>
    <initials>psa</initials>
    <remark><p>Recommended support for RFC2142-style mailbox in addition to XMPP address.</p></remark>
  </revision>
  <revision>
    <version>0.2</version>
    <date>2006-07-18</date>
    <initials>psa</initials>
    <remark><p>Removed extended addressing recommendations pending further review.</p></remark>
  </revision>
  <revision>
    <version>0.1</version>
    <date>2005-09-08</date>
    <initials>psa</initials>
    <remark><p>Initial version.</p></remark>
  </revision>
  <revision>
    <version>0.0.2</version>
    <date>2005-09-06</date>
    <initials>psa</initials>
    <remark><p>Added security considerations and XMPP Registrar considerations.</p></remark>
  </revision>
  <revision>
    <version>0.0.1</version>
    <date>2005-08-27</date>
    <initials>psa/jk</initials>
    <remark><p>First draft.</p></remark>
  </revision>
</header>
<section1 topic='Introduction' anchor='intro'>
  &RFC3920BISNOTE;
  <p>&rfc2142; specifies conventional electronic mailbox names for common services, roles, and functions related to SMTP, NNTP, and HTTP (such as postmaster@domain.tld, usenet@domain.tld, and webmaster@domain.tld). However, no such conventional email address or XMPP address (JID) has been specified for XMPP services. This document remedies that oversight.</p>
</section1>
<section1 topic='Email Address' anchor='email'>
  <p>Consistent with <cite>RFC 2142</cite>, a domain that offers a Jabber/XMPP service SHOULD provide an Internet mailbox of "XMPP" for inquiries related to that service.</p>
</section1>
<section1 topic='XMPP Address' anchor='xmpp'>
  <p>Many existing Jabber/XMPP server implementations use the bare domain (&DOMAIN;) of the server (e.g., "example.org") as an alias for the server administrators, such that a &MESSAGE; stanza addressed to that domain name is delivered to the JIDs of the server administrators. <note>Currently, this functionality does not apply to &IQ; or &PRESENCE; stanzas.</note> Unfortunately, using the "domain.tld" address as a way to direct messages to the server administrators may result in overloading of the bare domain address (i.e., it may be desirable to send messages to the server's address without having those messages delivered to the server admins, for example if the server doubles as a &xep0060; service). Therefore, it is instead RECOMMENDED to support a reserved address of &lt;xmpp@domain.tld&gt; for this functionality.</p>
  <p>In particular, it is RECOMMENDED for a service provider to handle XML stanzas with a 'to' address of &lt;xmpp@domain.tld&gt; as follows:</p>
  <ol start='1'>
    <li><p>For &MESSAGE; stanzas, deliver them to the administrators of the XMPP service.</p></li>
    <li><p>For &PRESENCE; stanzas, ignore them.</p></li>
    <li><p>For &IQ; stanzas, respond with a &unavailable; error.</p></li>
  </ol>
  <p>A service provider MAY aggregate presence from the server administrators so that the presence associated with &lt;xmpp@domain.tld&gt; reflects the presence of the server administrators (e.g., if at least one of the server administrators is online, then the alias &lt;xmpp@domain.tld&gt; will also appear to be online); alternatively, the service provider MAY refuse all requests for presence information about the &lt;xmpp@domain.tld&gt; address.</p>
</section1>
<section1 topic='Deployment Notes' anchor='deploy'>
  <p>The "domain.tld" at which the XMPP service is hosted need not be the same as the "domain.tld" at which the email service is hosted. For example, it is common for a service provider to host its XMPP service at a hostname such as "jabber.example.org" whereas email related to the service provider is sent to a hostname of "example.org". Thus while the XMPP address and email address may be the same for some service providers (e.g., both "xmpp@example.com"), that similarity is not necessary.</p>
  <p>Although some service providers that use the same address for both XMPP and email messaging may integrate delivery of messages sent by those mechanisms (e.g., XMPP messages sent while a user is offline are redirected to email delivery), XMPP and email remain separate messaging systems.</p>
   <p>A service provider that supports the functionality specified herein may advertise the service through an XMPP URI (see &rfc4622;) of &lt;xmpp:xmpp@domain.tld&gt; or (per &xep0147;) &lt;xmpp:xmpp@domain.tld?message&gt;, and through a Mailto URI (see &rfc2368;) of &lt;mailto:xmpp@domain.tld&gt;.</p>
</section1>
<section1 topic='Security Considerations' anchor='security'>
  <p>Providing or advertising contact addresses may open those addresses to unwanted communication. Server administrators should balance the need for openness with the desire for control over communication with customers and peers.</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>
</xep>