Summary

The IP multimedia subsystem (IMS) has been adopted, and will be adapted as required, to support session-based services, and other services based on session initiation protocol (SIP). This Recommendation describes how the IMS can be used in the NGN context following the fundamental principles described in [ITU-T Y.2001] and [ITU-T Y.2011] for providing the IP multimedia service component of the NGN functional architecture and describes its relationships to other service components.