3Com 4500 PWR 26-Port Configuration Manual page 309

25
Multicast Overview
In this manual, the term "router" refers to a router in the generic sense or a Layer 3 Ethernet switch
ru nning an IP multicast protocol.
Mult icast Overview
With the development of the Internet, more and more interaction services such as data, voice, and
video services are running on the network. In addition, highly bandwidth- and time-critical services,
such as e-commerce, Web conferencing
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 proces
Inform ation Transmission in the Unicast Mode
In unicast, the system establishes a separate data tran
information, and sends a separate copy of the information to the user, as shown in
Figure 25-1 Information transmission in the unicast mode
Source
Server
Packets for Host B
Packets for Host D
Packets for Host E
, online auctions, video on demand (VoD), and tele-education
ses for unicast, broadcast, and multicast traffic.
smission channel for each user requiring this
Host A
Receiver
Host B
Host C
Receiver
Host D
Receiver
Host E
25-1
Figure 25-1 :