Configuring Ip Multicast; Comparing Information Transmission Techniques; Unicast - HP A6600 Configuration Manual

Configuring IP multicast

This document focuses on the IP multicast technology and device operations. Unless otherwise stated, the
term multicast in this document refers to IP multicast.
Using multicast technology, a network operator can easily provide new value-added services, such as live
webcasting, web TV, distance learning, telemedicine, web radio, real-time video conferencing, and other
bandwidth-critical and time-critical information services.

Comparing information transmission techniques

As an information transmission technique that coexists with unicast and broadcast, the multicast technique
effectively addresses the issue of point-to-multipoint data transmission. By enabling high-efficiency
point-to-multipoint data transmission over a network, multicast greatly saves network bandwidth and
reduces network load.

Unicast

In unicast transmission, the information source must send a separate copy of information to each host that
needs the information.
Figure 1 Unicast transmission
Source
Packets for Host B
Packets for Host D
Packets for Host E
In Figure 1, assume that Hosts B, D, and E need the information. A separate transmission channel must be
established from the information source to each of these hosts.
In unicast transmission, the traffic transmitted over the network is proportional to the number of hosts that
need the information. If a large number of users need the information, the information source must send a
copy of the same information to each of these users. Sending many copies can place tremendous
pressure on the information source and the network bandwidth.
IP network
Receiver
1
Host A
Receiver
Host B
Host C
Receiver
Host D
Host E