4. Conclusion

The IMS domain must interconnect with existing networks, so that an IMS subscriber can continue to communicate with his or her subscriber correspondents (conventional circuit telephony, conventional IP telephony, 2G network, 3G network without IMS subscription, etc.). To achieve this, and in addition to the procedures specific to the IMS domain (see article [TE 7 512] , IP Multimedia domain), interworking procedures are also standardized.

The IMS domain promises the development of numerous services thanks to the outsourcing of services on dedicated application servers, but also...