Patent ID: 7903623

Claim:
A server based method for optimizing call setup latency comprising: updating client information using at least one server; identifying and updating parameters uniquely identifying from where at least one client is receiving communication service; determining, by the at least one server, at least one call group; choosing, by the at least one server, at least one designated responder from the at least one call group to respond for the at least one call group; selecting a plurality of designated responders as targets such that a total number of responses to a call setup message is reduced; computing hash outputs of the targets; performing a logical OR operation on selected bits of the hash outputs corresponding to the targets; and receiving a response from a target only when, up receiving a call setup message, the target computes a logical AND operation on a number included in an announcement message and a hash of the target's own user address and the following expression is true: (target's own user address)=(target's own user address) AND (the number included in the announcement message), wherein the number included in the announcement message is the result of said performing the logical OR operation on the selected bits of the hash outputs corresponding to the targets.