Method and apparatus for identifying an IMS service

摘要

A User Equipment (UE) and IP Multimedia Subsystem (IMS) network node for indicating the IMS services and IMS applications to which a Session Initiation Protocol (SIP) message relates. An IMS communication service identifier and an IMS application reference are added to the SIP message. The identifier and the reference may be added as Feature Tags. The reference may also be added as an a-line augmenting an m-line in a Session Description Protocol (SDP) part of the SIP message.