Operation Manual – MulticastH3C S7500 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,services highly dependent on bandwidth and real-time data interaction, such ase-commerce, web conference, online auction, video on demand (VoD), andtele-education have come into being. These services have higher requirements forinformation 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 separate copy information to the user, as shown inFigure 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 users B, D and E need this information. The source server establishestransmission channels for the devices of these users respectively. As the transmittedtraffic over the network is proportional to the number of users that receive this
