Chapter 1 Multicast Overview; Multicast Overview; Information Transmission In The Unicast Mode - H3C S3100 8C SI Operation Manual

Operation Manual – Multicast
H3C S3100 Series Ethernet Switches

Chapter 1 Multicast Overview

1.1 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.

1.1.1 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
Source
Server
Figure 1-1 Information transmission in the unicast mode
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
Figure 1-1:
Packets for Host B
Packets for Host D
Packets for Host E
Host A
Receiver
Receiver
Receiver
Host E
1-1
Chapter 1 Multicast Overview
Host B
Host C
Host D