scope:

The present document gives examples of signalling flows for the IP multimedia call control based on SIP and SDP. These signalling flows demonstrate the interaction with the IP-connectivity network (GPRS), and with the protocol provided at the Cx interface.

These signalling flows provide detailed signalling flows, which expand on the overview information flows provided in 3GPP TS 23.228 [2].

NOTE: The detailed signalling flows in the present document can be referenced, but the specification will not be further maintained. The example flows can contain errors and can only be regarded as guidelines for persons wanting an overview of how SIP messages with detailed header information could in some example cases look like within 3GPP. Other not documented signalling flows can be as relevant and compliant as the ones that are outlined in this specification.