3Com WX3000 operation manual Information Transmission in the Broadcast Mode

Figure 1-1Information transmission in the unicast mode

Host A

Receiver

Host B

Source

Server

Host C

Receiver

Host D

Packets for Host B	Receiver
Packets for Host D	Host E
Packets for Host E

Assume that Hosts B, D and E need this information. The source server establishes transmission channels for the devices of these users respectively. As the transmitted traffic over the network is in direct proportion to the number of users that receive this 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.

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 1-2shows information transmission in broadcast mode.

1-2