Huawei Quidway S6500 Series Operation Manual page 285

Operation Manual - Multicast Protocol
Quidway S6500 Series Ethernet Switches
Chapter 1 Multicast Overview
Note:
When running IP multicast protocols, Ethernet switches also provide the functions of
switches. We use routers in this manual to stand for not only the common routers but
also the layer 3 Ethernet switches running IP multicast protocols.
1.1 IP Multicast Overview
1.1.1 Problems with Unicast/Broadcast
The constant development of the Internet and increasing interaction of versatile data,
voice and video information over the network, has promoted the emergence of new
services like e-commerce, network conference, online auction, video on demand (VoD),
and tele-education. These services require higher information security and greater
rewards.
I. Unicast
In unicast mode, every user that needs the inforamtion receives a copy through the
channels the system separately establishes for them. See Figure 1-1.
Server
Figure 1-1 Data transmission in unicast mod
Suppose that Users B, D, and E need the information, the information source Server
establishes transmision channels with every of them. Since the traffic in transmission
increases with the number of users, excessive copies of the information would spread
Unicast
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Us er A
User B
User D
Us er E
e
1-1
Chapter 1 Multicast Overview
User C