Operation Manual – MulticastH3C S3100 Series Ethernet Switches Chapter 1 Multicast Overview1-1Chapter 1 Multicast Overview1.1 Multicast OverviewWith development of networks on the Internet, more and more interaction servicessuch as data, voice, and video services are running on the networks. In addition, highlybandwidth- and time-critical services, such as e-commerce, Web conference, onlineauction, video on demand (VoD), and tele-education have come into being. Theseservices 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. Thefollowing sections describe and compare data interaction processes in unicast,broadcast, and multicast.1.1.1 Information Transmission in the Unicast ModeIn unicast, the system establishes a separate data transmission channel for each userrequiring this information, and sends a separate copy of the information to the user, asshown in Figure 1-1:SourceServerReceiverReceiverReceiverHost AHost BHost CHost DHost EPackets for Host BPackets for Host DPackets for Host EFigure 1-1 Information transmission in the unicast modeAssume that Hosts B, D and E need this information. The source server establishestransmission channels for the devices of these users respectively. As the transmitted
