Application Research Of Layer-2 Multicast Technology And Its Implementation In ACR EMD

With rapid development of broadband streaming media services, such as IPTV and VOIP, multicast technology has been researched deeply and applied widely owing its advantages of high utilization of network bandwidth and the efficiency of alleviating server overload. Meanwhile, how to implement multicast function in layer-2 (data link layer) network devices such as switches becomes a research hotspot. Aiming at this issue, this paper mainly discusses two popular layer-2 multicast protocols, IGMP/MLD Snooping and IGMP/MLD Proxy, and puts emphasis on how to implement layer-2 multicast in Ethernet switches and access converging network devices, so as to meet the demand of the development trend of broadband streaming media services.This paper first describes the development status of layer-2 multicast technology, analyzes the principle of IGMP/MLD Snooping, and furthermore, puts forward an application scheme of the protocol in Ethernet switches. "Research on System Performance and Key Technologies of Large-scale Access Convergence Router" is an important part of Terabit transmission, Terabit routing, and Terabit switching (3TNet), the high-performance broadband information network key project of the national 863 Program of China. On the basis of the research, the paper gives a specific analysis of ACR system frame and its characteristics and the control process of broadband convergent multicast services, researches into the related problems and key techniques when implementing layer-2 multicast, and finally designs an enhanced application scheme of IGMP/MLD Proxy and applies it to the Expansion Multi- and Demultiplexer (EMD) of ACR so as to meet the different requirements of IPTV service and multicast service with PC as receivers. In the last part, software simulation tests show that the function and performance of Proxy software system module are able to meet the system demand.