The Research Of Multicast Routing Algorithm For PIM-SSM Multicast Model

With the rapid development of computer and network technology, more and moremultimedia services sprung up which are dependent on large-scale streaming transfertechnology. The rapid increase in multimedia services led to the rapid consumption ofnetwork bandwidth and network congestion problem. IP multicast service became asignificant pattern of large-scale streaming applications, by its unique superiority ofnetwork bandwidth does not need to increase exponentially with the number of users.The core issue of multicast communication is Multicast routing, multicast routingalgorithm is one of the key technologies for multicast routing. At present, PIM-SSMmulticast model is widely used in streaming media distribution, such as IPTV. But ituses shortest path algorithm of nearest to source construct the multicast tree, which theutilization rate of resources is low. This paper researches on multicast routingalgorithms and implementation technology of the protocols, under the Delay-Boundedconditions. We focus on reducing the costs of the multicast tree generation and thecomplexity of the algorithm in PIM-SSM multicast model. Our main work andcontributions are summarized as follows:(1)We research and analyze the current IP multicast routing algorithm, summarizethe constraints of the IP multicast transmission. Then, we proposed a Delay-Boundedmulticast routing algorithm with high performance called SPTA. The algorithm has highresource utilization, as the node join into the multicast group by finding a shortest pathin the existing multicast tree under the delay bounded.(2)Base on SPTA algorithm, we proposed a new implementation mode ofPIM-SSM, including the format of the protocol, the node processing behavior, and so on.It proves that, the implementation mode of PIM-SSM based on SPTA algorithm issuperior to the traditional shortest path algorithm of nearest to source.(3)Base on the MCRSIM tool developed by Salama etc., we establish simulationplatform for simulating the performance of multicast algorithm, and make simulationfor the SPTA, the shortest path tree and Jia’s algorithm. Simulation results show that,SPTA algorithm has the advantage of low complexity, low cost, high efficiency.In summary, we research the construction of multicast routing tree in large-scalestreaming media transfer, and propose a new multicast routing algorithm for PIM-SSMmulticast model. It has some theoretical significance and practical value to building alow cost multicast routing tree.