Planning IP Multicasting

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

With IP multicasting, one device can send a single data stream that the network replicates only as necessary so that multiple devices receive the data. Because of the minimal overhead required to create the data stream and the low overhead on the network, multicast communication is particularly suitable for multiple-user multimedia applications such as video conferencing, distance learning, and collaborative computing. You can also use multicast traffic to discover resources on the internetwork and to support datacasting applications such as file distribution or database synchronization.

Using the IP multicast components of the Windows Server 2003 TCP/IP protocol and the Routing and Remote Access service, you can send and receive IP multicast traffic from multicast-enabled portions of your intranet or the Internet and from remote access clients. You can use IP multicast to optimize server loading and network bandwidth.

Figure 1.13 shows the tasks involved in planning IP multicasting.

Figure 1.13   Planning IP Multicasting

In multicast routing, routers communicate multicast group membership information to each other using multicast routing protocols, and forward data across the internetwork. Multicast forwarding refers to the process of forwarding multicast traffic to networks on which other multicast devices are listening. The multicast-capable portion of the Internet is referred to as the Internet multicast backbone, or MBone.

All computers running Windows Server 2003 can both send and receive IP multicast traffic. Windows Server 2003 TCP/IP can listen for IPv4 multicast traffic and use a multicast forwarding table to determine where to forward incoming multicast traffic.

Figure 1.14 shows one common configuration of IP multicast components. For examples of a number of supported multicast configurations, see the Networking Collection of the Windows Server 2003 Technical Reference (or see the Networking Collection on the Web at https://www.microsoft.com/reskit).

Figure 1.14   IP Multicast Components