Reliability of IMS architecture

The IP multimedia subsystem (IMS) enables an access-agnostic next generation network (NGN) that integrates wireless, wireline and Internet technologies. IMS provides for real-time voice and data services over a packet-switched domain via a session initiation protocol (SIP) infrastructure. It also offers a cost-effective platform for the creation and deployment of IP-based multimedia services. Given the wide scope of services that can be offered with IMS it is important to develop a framework to analyze the reliability of these services. Using an IMS reference architecture, this paper presents a network level failover analysis using the IMS architecture capabilities and shows its impact on improving service reliability. We show how to analyze the end-to-end service reliability in terms of detection and recovery mechanisms and redundancy.