ALTERNATE ROUTING OF VOICE COMMUNICATION IN A PACKET-BASED NETWORK

摘要

A method for performing alternate and therefore least cost routing in distributed H.323 Voice over IP (VoIP) networks is provided. With this method, the VoIP network consists of a hierarchy of gatekeeper (GK) functions to provide alternate routing, network element redundancy, and scalability. The alternate routing function is performed by a directory gatekeeper with route selection advancing from a first route to a second route by either of two conditions: (1) there are no resources available to terminate the call in the first zone; and (2) a lack of response to the directory GK request for such resources.