Patent ID: 8315165

Claim:
A method executed at least in part in a computing device for managing a resilient and survivable architecture of an enhanced communication system, the method comprising: enabling clients to register with a registrar cluster to receive communication services from the system, wherein the architecture of the system includes at least one data center of registrar clusters and a user services server, at least one branch office, and a plurality of function-specific servers; providing data center survivability by assigning primary and backup registrar clusters at different data centers; providing cluster survivability by enabling clients to failover to an alternate registrar within the same cluster from their assigned home registrar in a transparent manner; providing call survivability by selecting one of: an alternate inter-cluster call path and a Public Switched Telephone Network (PSTN) call path; and providing network survivability by enabling clients to discover a registrar cluster through one of: a Session Initiation Protocol (SIP) Dynamic Host Configuration Protocol (DHCP) discovery and a SIP multicast discovery.