SMC Networks TIGERSWITCH SMC6752AL2 Manual De Usuario

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Multicasting is used to support real-time 
applications such as videoconferencing 
or streaming audio. A multicast server 
does not have to establish a separate 
connection with each client. It merely 
broadcasts its service to the network, and 
any hosts that want to receive the 
multicast register with their local 
multicast switch/router. Although this 
approach reduces the network overhead 
required by a multicast server, the 
broadcast traffic must be carefully 
pruned at every multicast switch/router it 
passes through to ensure that traffic is 
only passed on to the hosts which 
subscribed to this service.

This switch uses IGMP (Internet Group Management Protocol) to query 
for any attached hosts that want to receive a specific multicast service. It 
identifies the ports containing hosts requesting to join the service and 
sends data out to those ports only. It then propagates the service request 
up to any neighboring multicast switch/router to ensure that it will 
continue to receive the multicast service. This procedure is called multicast 
filtering. 

The purpose of IP multicast filtering is to optimize a switched network’s 
performance, so multicast packets will only be forwarded to those ports 
containing multicast group hosts or multicast routers/switches, instead of 
flooding traffic to all ports in the subnet (VLAN).

Unicast
Flow

Multicast
Flow