Network Working Group P. Saint-Andre, Ed. Request for Comments: 3921 Jabber Software Foundation Category: Standards Track October 2004

(XMPP): Instant Messaging and Presence

Extensible Messaging and Presence Protocol

Status of this Memo

• This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

• Copyright (C) The Internet Society (2004).

Abstract

• This memo describes extensions to and applications of the core features of the Extensible Messaging and Presence Protocol (XMPP) that provide the basic instant messaging (IM) and presence functionality defined in RFC 2779.

Saint-Andre Standards Track [Page 1]

RFC 3921 XMPP IM October 2004

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Syntax of XML Stanzas . . . . . . . . . . . . . . . . . . . . . . . 4
3. Session Establishment . . . . . . . . . . . . . . . . . . . . . . . 10
4. Exchanging Messages . . . . . . . . . . . . . . . . . . . .. . . . 13
5. Exchanging Presence Information . . . . . . . . . . . . . . . 16
6. Managing Subscriptions . . . . . . . . . . . . . . . . . . . . . . . 26
7. Roster Management . . . . . . . . . . . . . . . . . . . . . . . . . 27
8. Integration of Roster Items and Presence Subscriptions . . . 32
9. Subscription States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10. Blocking Communication . . . . . . . . . . . . . . . . . . . 62
11. Server Rules for Handling XML Stanzas . . . . . . . . . . . 85
12. IM and Presence Compliance Requirements . . . . . . . . . . 88
13. Internationalization Considerations . . . . . . . . . . . . 89
14. Security Considerations . . . . . . . . . . . . . . . . . . 89
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . 90
16. References . . . . . . . . . . . . . . . . . . . . . . . . . 91
17. vCards . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 B. XML Schemas. . . . . . . . . . . . . . . . . . . . . . . . . 93 C. Differences Between Jabber IM/Presence Protocols and XMPP. . 105 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 106 Author's Address. . . . . . . . . . . . . . . . . . . . . . . . . 106 Full Copyright Statement. . . . . . . . . . . . . . . . . . . . . 107