Alternate routing of voice communication in a packet-based network

A directory gatekeeper (3020) for performing alternate routing of calls through a plurality of gateway resources (3040), where the directory gatekeeper comprising: one or more communications devices that provide access to a plurality of controllers resource management ( 3030), each resource management controller associated with one or more of the plurality of gateway resources; a memory device that stores a list of paths where each path is associated with one of the plurality of controllers resource management; and operable to receive a request via the device or devices communications processor, characterized in that in response to a request received, the processor is adapted to perform alternate routing executing instructions to select a route from the route list using the corresponding controller resource management to determine the availability of resources, further characterized in that it is adapted to: identify one or more candidate routes based on the received request; and for each of the candidate routes: select a candidate route from said one or more candidate routes; determine if the selected candidate route is available; and if the selected candidate route is available, send a reply to the request received indicating that the candidate route is available.