Multicast
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Multicast is a routing scheme that enables data delivery to a group of hosts. Multicast allows the source to transmit the data once, while routers in the network take care of duplicating the data and transmitting it to the registered hosts. Multicast requires UDP support. TCP is not designed to work with Multicast, but there are some reliable Multicast protocols that can replace TCP such as Pragmatic General Multicast (PGM).