Patent ID: 7720084

Claim:
A system for routing calls through a network, the system comprising: an inbound gatekeeper operable to receive requests to setup data sessions and issue routing requests for determining routes for the requested data session; a plurality of resource zones, wherein each zone has an associated resource management gatekeeper and a plurality of outbound gateway resources configured to terminate data sessions received by the inbound gatekeeper; and a directory gatekeeper having memory storing a plurality of routes through the resource zones, each route corresponding to one of the resource management gatekeepers, and wherein, in response to a routing request received from the inbound gatekeeper, the directory gatekeeper requests an outbound gateway resource from a resource management gatekeeper associated with a selected route, and wherein the selected resource management gatekeeper checks for an available outbound gateway resource among the plurality of outbound gateway resources in the resource zone of the selected resource management gatekeeper, wherein if an available outbound gateway resource is identified in the resource zone, the selected resource management gatekeeper notifies the directory gatekeeper of the available outbound gateway resource, and wherein if an available outbound gateway resource is not identified in the resource zone, the directory gatekeeper requests resources from another resource management gatekeeper in another zone by selecting another route corresponding to the other resource management gatekeeper.