Methods are disclosed for limiting the scope of flooding of dense mode IP multicast calls. A multicast scope value (e.g., TTL scope or hop limit) is determined for each call based on the locations of participating devices for the call at one or more destination sites, zones or zone clusters. The multicast scope value is adjusted based on user location, as wireless users may roam from site to site or zone to zone (or zone cluster). When a user sources packets for a call, the packets include the multicast scope value. The packets are transported, according to dense mode routing protocols, across various router interfaces of a packet network. The router interfaces are assigned various thresholds based on their location in the network. Packets are not flooded across router interface(s) having thresholds that exceed the packet's multicast scope value. Thus, through judicious choice of multicast scope value, the flooding of packets for a call may be constrained to within a single zone (or zone cluster), or allowed to proceed to remote zones.