Media State under Preconditions in the Session Initiation Protocol (SIP)
Ericsson
Ericsson
ZTE
In this document, we describe how a UAS (User Agent Server) involved in a session modification can explicitly signal the point where the new session parameters start being used. Explicitly signalling such a change in the session parameters can be useful so that network intermediaries such as B2BUAs (Back-to-back User Agents) have a clear picture of the session's state at every point.