Updated: January 21, 2005
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Multicasting is useful for the point-to-multipoint delivery of information on an internetwork. You can use three mechanisms for point-to-multipoint delivery:
Send the information to each endpoint individually by using unicast addresses. The disadvantages of this method are the duplication of network traffic and the overhead of maintaining a list of unicast endpoints.
Send the information in a single packet by using a broadcast address. The advantages of this method are the use of a single packet and no overhead for keeping lists of recipients. The disadvantages are the use of broadcast packets (which disturbs all nodes on the network) and the fact that broadcasts are not forwarded by routers. A broadcast packet reaches everyone on a network, but not everyone on the internetwork.
Send the information in a single packet by using a multicast address. The advantages of this method are the use of a single packet and no overhead for keeping lists of recipients. Unlike broadcast packets, multicast traffic does not disturb those nodes who are not listening for it. Routers can be multicast-capable and forward the multicast packet to all networks where there is at least one node listening.
Multicasting is the best choice for point-to-multipoint delivery.
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