Research On The Routing Algorithm Of Source Specific Aggregated Multicast

Multicast technology is an effective way of sending information from one source to a few of receivers. Comparing with unicast, multicast can greatly reduce the cost of transmission of data source and the network. Now, Multicast is one of the hot spots of research on network technology. But until now, multicast technology has not been used widely, because there still are some problems need to be resolved, including the scalability of multicast. When there are lots of multicast groups in the network, every pot has to maintain lots of forwarding states. These states occupy the routers'memory spaces and decrease the forwarding efficiency and the scalability of the network. The number of the forwarding state increases with the number of groups. This paper does research on one method of resolving the scalability problem——aggregated multicast. A new group-tree matching method is proposed and extends the NS₂ stimulating platform in order to support the source specific aggregated multicast.First, on the basic of deeply analyzing the principle of the aggregated multicast and all kinds of group-tree matching methods, a new group-tree matching algorithm——FDMA algorithm (Fast Dynamic Match Algorithm) is proposed. FDMA algorithm can raise the aggregating speed. And by the management of aggregated trees, it can decrease matching times. So the real-time property is improved greatly.Second, the stimulating platform NS₂ is also analyzed and a new module to support the ASSM(Source Specific Aggregated Multicast) protocol is built. The routing functions are added in order to make NS₂ support the ASSM protocol.The last, stimulations are performed on the extended NS₂ platform. FDMA algorithm is used in the ASSM protocol. Comparisons to other group-tree matching algorithm are done in different stimulations. The result shows thatFDMA algorithm has a better performance than others. In the end of the paper, the future works are provided.