Extensible Messaging and Presence Protocol - Definition and Overview

Extensible Messaging and Presence Protocol, or XMPP, is an open, XML-based protocol for near real-time extensible messaging and presence events. It is the core protocol of the Jabber Instant Messaging and Presence technology which is currently deployed on thousands of Jabber servers across the Internet and is used by millions of people worldwide. The IETF XMPP working group aims to adapt the XMPP for use as an IETF Instant Messaging and presence technology.

Specifications

The IETF XMPP working group has produced a number of RFCs:

• RFC_3920 (http://www.ietf.org/rfc/rfc3920.txt), Extensible Messaging and Presence Protocol (XMPP): Core which describes client-server messaging using two open ended XML streams. XML streams consist of <presence/>, <message/> and <iq/> (info/query) as illustrated in the example client-server conversation. A connection is authenticated with Simple Authentication and Security Layer (SASL) and encrypted with Transport Layer Security (TLS).

• RFC_3921 (http://www.ietf.org/rfc/rfc3921.txt), Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence describes instant messaging (IM), the most common application of XMPP.

• RFC_3922 (http://www.ietf.org/rfc/rfc3922.txt), Mapping the Extensible Messaging and Presence Protocol (XMPP) to Common Presence and Instant Messaging (CPIM) relates XMPP and the Common Presence and Instant Messaging (CPIM) specifications.

• RFC_3923 (http://www.ietf.org/rfc/rfc3923.txt), End-to-End Signing and Object Encryption for the Extensible Messaging and Presence Protocol (XMPP) describes end to end encryption of XMPP messages using S/MIME. Conflicting this proposal, many clients currently use GPG for encrypting messages.

Implementations

• XMPP is implemented by the numerous Jabber clients
• Twisted Matrix Labs' Twisted (http://twistedmatrix.com/products/twisted) (a Python based framework for writing networked applications) supports XMPP.

External links

• XMPP working group (http://www.xmpp.org)