System and methods for confining multicast routing trees to within single zones of a multi-zone communication systems, thereby enabling faster convergence of the trees relative to trees spanning multiple zones. Separate multicast routing trees are established using different multicast addresses in a source zone and one or more listening zones. Packets for a call distributed by routers (104, 116) of a packet network within the source zone via a source zone multicast address are received by a source zone packet duplicator (132). The source zone packet duplicator forwards the packets, via routers (116, 118, 120, 122) of the packet network using unicast routing, to various listening zone packet duplicators (136, 138). The listening zone packet duplicators, upon receiving the packets, separately distribute the packets within their respective zones via the packet network using different multicast addresses of the listening zones. The source zone and listening zones may be redefined during the call as the source changes or moves to different zones.