The XMPP Presence and Instant Messaging protocol is the core protocol on Cisco Unified Presence. This interface provides instant messaging, availability and roster management services.
The basic eXtensible Messaging and Presence Protocol is specified in the following industry standards:
RFC-3920 - Extensible Messaging and Presence Protocol (XMPP): Core
RFC-3921 - Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence
In addition, there are many extension drafts described in XMPP Extension Protocols (XEPs). For a list of supported Cisco Unified Presence XEPs please refer to the "Developer Guide for Cisco Unified Presence" for your release of Cisco Unified Presence.