http://www.rfc-editor.org/rfc/rfc7248.txt
RFC 7248: Interworking between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP): Presence, P. Saint-Andre, A. Houri, J. Hildebrand2014-05-01T23:00:00-00:00This document defines a bidirectional protocol mapping for the exchange of presence information between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP).