R21xx-HP FlexFabric 11900 IP Multicast Configuration Guide

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Multicast applications
• Multimedia and streaming applications, such as web TV, web radio, and real-time video/audio
conferencing
• Communication for training and cooperative operations, such as distance learning and
telemedicine
• Data warehouse and financial applications (stock quotes)
• Any other point-to-multipoint application for data distribution
Multicast models
Based on how the receivers treat the multicast sources, the multicast models include any-source multicast
(ASM), source-filtered multicast (SFM), and source-specific multicast (SSM).
ASM model
In the ASM model, any sender can send information to a multicast group as a multicast source, and
receivers can join a multicast group identified by a group address and get multicast information
addressed to that multicast group. In this model, receivers do not know the positions of the multicast
sources in advance. However, they can join or leave the multicast group at any time.
SFM model
The SFM model is derived from the ASM model. To a sender, the two models appear to have the same
multicast membership architecture.
The SFM model functionally extends the ASM model. The upper-layer software checks the source address
of received multicast packets and permits or denies multicast traffic from specific sources. Therefore,
receivers can receive the multicast data from only part of the multicast sources. To a receiver, multicast
sources are not all valid, but are filtered.
SSM model
Users might be interested in the multicast data from only certain multicast sources. The SSM model
provides a transmission service that enables users to specify at the client side the multicast sources in
which they are interested.
The main difference between the SSM model and the ASM model is that in the SSM model, receivers
have already determined by some other means the locations of the multicast sources. In addition, the
SSM model uses a multicast address range that is different from the ASM/SFM model. Dedicated
multicast forwarding paths are established between receivers and the specified multicast sources.
Multicast architecture
IP multicast addresses the following issues:
• Where should the multicast source transmit information to? (Multicast addressing.)
• What receivers exist on the network? (Host registration.)