IP Multicast Support
IP Multicast Support |
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The Internet Multicast Backbone, or MBone, is the portion of the Internet that supports multicast routing and forwarding of Internet-based IP multicast traffic. The MBone structure consists of a series of multicast-enabled islands, collections of contiguous networks, connected together using tunnels. Multicast traffic is passed from one island to another by tunneling: encapsulating the IP multicast packet with an additional IP header addressed from one router in a multicast island to another router in another multicast island. Tunneling allows the multicast traffic to travel across portions of the Internet that do not support multicast forwarding.
The MBone is used for audio and video multicasts of Internet Engineering Task Force (IETF) meetings, the National Aeronautics and Space Administration, and the United States House of Representatives and Senate, among others. Support for the MBone might vary among Internet service providers (ISPs).