Common Notations In Multicast; Advantages And Applications Of Multicast - HP A5500 SI Switch Series Configuration Manual

manage multicast group memberships on stub subnets with attached group members. A multicast
router itself can be a multicast group member.
For a better understanding of the multicast concept, you can compare multicast transmission to the
transmission of TV programs.
Table 1 An analogy between TV transmission and multicast transmission
TV transmission
A TV station transmits a TV program through a
channel.
A user tunes the TV set to the channel.
The user starts to watch the TV program
transmitted by the TV station via the channel.
The user turns off the TV set or tunes to another
channel.

Common notations in multicast

The following notations are commonly used in multicast transmission:
(*, G)—Indicates a rendezvous point tree (RPT), or a multicast packet that any multicast source
•
sends to multicast group G. Here, the asterisk represents any multicast source, and "G" represents
a specific multicast group.
(S, G)—Indicates a shortest path tree (SPT), or a multicast packet that multicast source S sends to
•
multicast group G. Here, "S" represents a specific multicast source, and "G" represents a specific
multicast group.
NOTE:
For more information about the concepts RPT and SPT, see the chapters "PIM configuration" and "IPv6
PIM configuration."

Advantages and applications of multicast

Advantages of multicast
The multicast technique has the following advantages:
Enhanced efficiency—Reduces the processor load of information source servers and network
•
devices.
Optimal performance—Reduces redundant traffic.
•
Distributed application—Enables point-to-multipoint applications at the price of minimum network
•
resources.
Applications of multicast
The multicast technique has the following applications:
Multimedia and streaming applications, such as web TV, web radio, and realtime video/audio
•
conferencing
Multicast transmission
A multicast source sends multicast data to a multicast
group.
A receiver joins the multicast group.
The receiver starts to receive the multicast data that the
source is sending to the multicast group.
The receiver leaves the multicast group or joins another
group.
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