Patent ID: 7031279

Claim:
A gatekeeper in an Internet Protocol (IP) telephony system, comprising: a conference managing unit configured to process a multimedia communication control message, perform third-party pause and rerouting (3PPR) signaling, and perform a handoff and call transfer signaling for a mobile terminal; a registration, admission and status (RAS) managing unit configured to process a RAS message, interface with a network layer, and communicate with the conference managing unit while processing a care of address (COA) registration for the handoff of the mobile terminal; a RAS message processor configured to encode and decode the RAS message; a call managing unit configured to processes a call signal message; a H.225 call signal processor configured to carry the call signal message on a corresponding carrier and encode and decode the call signal message; a H.245 control message processor configured to encode and decode messages of the call managing unit and conference managing unit in accordance with the PER; a supplementary service managing unit configured to call the conference managing unit while processing a message for a supplementary service; a call set-up information node configured to store information obtained when the call signal message is processed; a conference information node configured to store control information obtained when the multimedia communication control message is processed; a supplementary service information node configured to store information obtained when the message for the supplementary service is processed; and a user information buffer configured to store user information managed by the RAS managing unit.