User Manual
UMN:CLI
V5824G
327
9 IP Multicast
IP communication provides three types of packet transmission: unicast, broadcast and
multicast. Unicast is the communication for a single source host to a single destination
host. This is still the most common transmission form in the IP network. Broadcast is the
communication for a single source host to all destination hosts on a network segment.
This transmission is also widely used especially by network protocols, but it sometimes
may not be efficient for those hosts in the subnet who are not participating in the
broadcast. Multicast is the communication for a single or many source hosts to a specific
group of destination hosts, which is interested in the information from the sources. This
type of packet transmission can be deployed for a number of applications with more
efficient utilization of the network infrastructure.
The point of implementing multicast is how to deliver source traffic to specific destinations
without any burden on the sources or receivers using the minimized network bandwidth.
The solution is to create a group of hosts with addressing the group, and to let the
network determine how to replicate the source traffic to the receivers. The traffic will then
be addressed to the multicast address and replicated to the multiple receivers by network
devices. Standard multicast protocols such as IGMP and PIM provides most of these
capabilities.
IP multicast features on the V5824G consist of the group membership management,
Layer 2 multicast forwarding, and Layer 3 multicast routing, which allow network
administrators to successfully achieve the effective and flexible multicast deployment.
shows an example of the IP multicast network. In this case, the V5824G is
configured only with IGMP snooping (L2 multicast forwarding feature) in the Layer 2
network.
Fig. 9.1
The V5824G with IGMP Snooping