Patent ID: 7366521

Claim:
A controller for allocating call identity values to call connections associated with a switch, said switch capable of handling call connections between calling devices and called devices on a plurality of trunk lines associated with said switch, said controller comprising: N call application nodes capable of executing a plurality of identity server processes that allocate call identity values to said call connections; and a load sharing group capable of selecting one of a first and second identity server processes to allocate a call identity value to a new call connection according to a load distribution algorithm, wherein, when said new call connection is ended, said selected identity server process is located based on said call identity value and said selected identity server process releases said call identity value by marking said call identity value as unallocated, wherein said first identity server process comprises a first primary-backup identity server group, comprising, a first primary identity server application, executing on a first call application node, and a first backup identity server application, associated with said first primary identity server application, and wherein, responsive to a failure of the first primary identity server application, the first backup identity server application assumes the role of first primary identity server application.