http://www.rfc-editor.org/rfc/rfc4083.txt
RFC 4083: Input 3rd-Generation Partnership Project (3GPP) Release 5 Requirements on the Session Initiation Protocol (SIP), M. Garcia-Martin2005-05-01T23:00:00-00:00The 3rd-Generation Partnership Project (3GPP) has selected Session Initiation Protocol (SIP) as the session establishment protocol for the 3GPP IP Multimedia Core Network Subsystem (IMS). IMS is part of Release 5 of the 3GPP specifications. Although SIP is a protocol that fulfills most of the requirements for establishing a session in an IP network, SIP has never been evaluated against the specific 3GPP requirements for operation in a cellular network. In this document, we express the requirements identified by 3GPP to support SIP for Release 5 of the 3GPP IMS in cellular networks. This memo provides information for the Internet community.