The Research And Simulation Of QoS-based Multicast Routing Algorithms

With the development of Internet, the data transported through networks is increasing rapidly in exponential grade. A great deal of multimedia services are becoming the main part of the transporting information. The demand to network has bacome integrated multimedia service from simple data transport, while the traditional P2P communication method has low efficiency and waste abundant of bandwidth. Multicast technology is the point to multi-points (or multi-points to multi-points) communication way which can make use of bandwidth effectively. This kind of network interconnection mode is widely researched and put into application nowadays. Generally, the application of multicast technology should be confirm the multicast path first, which is the problem that the multicast algorithm is used to settle.The background of multicast evolution is introduced in this thesis first, together with several typical multicast routing protocols, current QoS architectures, routing strategies and the relative QoS parameters. This thesis put forward a kind of multi-paths algorithm based on the QoS multicast routing. Compare to others, this algorithm reduces the routing cost because it forwards control messages only when the path meets the QoS needs. On the base of the algorithm, this thesis gives a kind of paths combination algorithm too, the algorithm enhances the success ratio further and enhances the link utilization at the same time.The thesis is divided into six chapters:Chapter 1 briefly introduces the correspond content of multicast, including developing background of multicast routing, research status, multicast routing algorithms, multicast routing protocols and the relative concepts of multicast tree, it also introduces the source and meaning of this thesis.Chapter 2 introduces QoS multicast technique, including QoS system architecture, QoS routing strategy, QoS parameters, QoS multicast research status, the mathematic model of QoS multicast and so on.Chapter 3 introduces the correspond content of network simulation, the emphasis is a kind of network simulation tool—Opnet, including its simulation theory, simulation process and so on.Chapter 4 introduces a kind of multi-path algorithm put forward by the thesis, and this is the emphasis of the thesis, including the mathematic model and the particular realization process of the algorithm, the simulation results analyse is given in the chapter too.Chapter 5 gives an amelioration paths combination algorithm based on the algorithm in chapter 4. In this chapter, the combination algorithm is introduced in detail, including realization process, simulation experiment and results analyse.A summarization of the thesis is given in the last chapter.This work is supported by National Natural Science Foundation of China(project NO, 90304018).