scope:

This Recommendation specifies signalling requirements and protocol profiles of customized ring-back tone (CRBT) service in support of customized multimedia ringing (CMR). This Recommendation also contains signalling flows.

The CRBT service is defined in next generation networks (NGNs) including IP multimedia subsystems (IMS) and call-server based networks.

This Recommendation covers the protocol profiles over the user-network interface (UNI) and network-to-network interface (NNI) based on [ITU-T Q.3402] and [ITU-T Q.3401], respectively. In addition, it also covers [ITU-T H.248.1] based protocol profile for the interface between the access media gateway functional entity (AMG-FE) and the service control functions. More detailed protocol profiles for other interfaces may be subject to future specifications.