Patent ID: 7882226

Claim:
For use in a telecommunication network, an Internet Protocol (IP) multimedia subsystem comprising: a processor; an IP switch capable of receiving Common Open Policy Service (COPS) messages from an external gateway GPRS support node; and a plurality of call application nodes capable of executing a plurality of Policy Decision Function (PDF) application groups, wherein said IP switch distributes said COPS messages to said plurality of call application nodes according to a load sharing algorithm, wherein the PDF application groups provide a framework for controlling unicast, multicast, and groupcast communications, wherein the IP switch is further configured to provide each of the plurality of call application node with a virtual IP (VIP) address that migrates across at least two nodes and is associated with at least two media access control (MAC) addresses of at least two nodes and is associated with each service the call application node is configured to perform, and wherein the IP switch is further configured to detect a failure of one of the plurality of call application nodes, and wherein the IP switch is configured to avoid sending data to a VIP with a detected failure.