scope:

This Recommendation specifies signalling requirements and protocol profiles for NGN customized ringing tone (CRT) service. This Recommendation also contains signalling flows.

The CRT service is defined in the next generation network (NGN), including IP multimedia subsystem (IMS) and call-server based networks. This Recommendation is based on [b-ITU-T Y.2214] and covers in this version only the signalling requirements and protocol profiles for the presentation features of CRT. The capability for the CRT filtering features is for further study.

This Recommendation covers the protocol profiles over user network interface (UNI) and network-to-network interface (NNI) based on [ITU-T Q.3402] and [ITU-T Q.3401], respectively. Detailed protocol profiles for other interfaces may be subject to future specifications.