Satellite communication multicast processing techniques

A satellite communication system which performs multicast switching on data cells. A switch 80 receives the data cells at a set of input ports IP1 and directs those including a multicast routing code to a first set of output ports OP2 or OP128. The switch 80 also directs data cells effectively omitting the multicast routing code to a second set of output ports OP1. One or more multicast replication modules 110, 130 are coupled to the first set of output ports and replicate data cells requiring multicast processing. During the processing, the multicast routing code is effectively omitted and the replicated cells are coupled to input ports IP2 or IP 128 so that the replicated data cells are transmitted to the second set of output ports OP1. An outbound processing module 100 is coupled to output ports OP1 for processing the data cells for transmission over a satellite downlink transmitter 104.