Information Transmission In The Unicast Mode; Multicast Overview - 3Com WX3000 Series Operation Manual

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Multicast Overview

The term switch used throughout this chapter refers to a switching device in a generic sense or the
switching engine of the WX3000 series devices.
The sample output information in this manual was created on the WX3024. The output information
on your device may vary.
Multicast Overview
With development of networks on the Internet, more and more interaction services such as data, voice,
and video services are running on the networks. In addition, highly bandwidth- and time-critical services,
such as e-commerce, Web conference, online auction, video on demand (VoD), and tele-education
have come into being. These services have higher requirements for information security, legal use of
paid services, and network bandwidth.
In the network, packets are sent in three modes: unicast, broadcast and multicast. The following
sections describe and compare data interaction processes in unicast, broadcast, and multicast.

Information Transmission in the Unicast Mode

In unicast, the system establishes a separate data transmission channel for each user requiring this
information, and sends a separate copy of the information to the user, as shown in
1-1
Figure 1-1: