Methods for managing bandwidth in a packet-based communication system are disclosed wherein the packet-based communication system includes one or more reservation proxy elements associated with a plurality of zones. Specifically, the methods comprise receiving a call request for a talkgroup call and identifying a multicast group address for the call. Then, determining locations of one or more participating devices for the call, thereby determining a number of participating zones of the plurality of zones, the reservation proxy elements associated with the participating zones defining participating reservation proxy elements and communicating the multicast group address to the participating reservation proxy elements. Finally, the methods comprise receiving, from the participating reservation proxy elements, indicia of availability of communication resources on one or more links between the participating zones.