Information Transmission In The Broadcast Mode; Information Transmission In The Multicast Mode - H3C S5100-SI Series Operation Manual

Operation Manual – Multicast
H3C S5100-SI/EI Series Ethernet Switches
information, when a large number of users need this information, the server must send
many pieces of information with the same content to the users. Therefore, the limited
bandwidth becomes the bottleneck in information transmission. This shows that unicast
is not good for the transmission of a great deal of information.

1.1.2 Information Transmission in the Broadcast Mode

When you adopt broadcast, the system transmits information to all users on a network.
Any user on the network can receive the information, no matter the information is
needed or not.
Figure 1-2 Information transmission in the broadcast mode
Assume that Hosts B, D, and E need the information. The source server broadcasts this
information through routers, and Hosts A and C on the network also receive this
information.
As we can see from the information transmission process, the security and legal use of
paid service cannot be guaranteed. In addition, when only a small number of users on
the same network need the information, the utilization ratio of the network resources is
very low and the bandwidth resources are greatly wasted.
Therefore, broadcast is disadvantageous in transmitting data to specific users;
moreover, broadcast occupies large bandwidth.

1.1.3 Information Transmission in the Multicast Mode

As described in the previous sections, unicast is suitable for networks with sparsely
distributed users, whereas broadcast is suitable for networks with densely distributed
Figure 1-2 shows information transmission in broadcast mode.
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Chapter 1 Multicast Overview