Centralized management technique of call control data

A method for managing call control data installed in respective ones of a plurality of call agents which is distributed on a packet-based network, comprising the steps of:

• a) setting each of the call agents to be a client of a server which is provided on the packet-based network by the steps of:
• a.1) the call agent transmitting a server search message to the server;
• a.2) when receiving the server search message, the server determining whether the call agent can be managed;
• a.3) when it is determined that the call agent can be managed, the server transmitting a response message back to the call agent;
• a.4) when receiving the response message, the call agent transmitting a registration request to the server;
• and
• a.5) when receiving the registration request, the server registering the call agent as a client when the call agent satisfies registration requirement;
• wherein when it is determined in the step (a.2) that the call agent cannot be managed, the server transmits a re-search instruction message to the call agent, the re-search instruction message designating another server, and wherein, when receiving the re-search instruction, the call agent transmits a server search message to the designated server;
• at the server,
• b) storing master call control data required in respective ones of the call agents;
• c) managing the master call control data;
• and
• at each of the call agents,
• d) storing a copy of corresponding master call control data so that the call agents perform network-wide call control.