Multicast Network Performance Impact Factors And Optimization Methods

In recent years, as the development and wide use of Stream Media and video based on the Internet, IP Multicasting technology has been quickly expanded. Because of that IP Multicasting can send data to multiple receivers from one source or more in an efficient and extendable way, and that it can save bandwidths and reduce the possibility of congestion, many experts believe that it is one of the most important technologies of the Next Generation of Internet. It is very important to find parameters that affect the performance of Multicast network. However, as the network itself is deeply complex, it is too difficult to analyze parameters that affect the performance of Multicast network. With the development of computer technology and network topology generation tools, the above problem has been well dealt, Network Simulation (NS) based on topology generation has already been one of the important ways to design network and test performance. NS-2 is an ideal test bed to compare protocols because it provides many publicly available simulators with a large protocol library. One can do Multicast simulation by NS-2, and through dealing with the result of simulation, the effect of Multicast routing protocol, network topology, Multicast group size and the number of Multicast groups to the performance of Multicast network can be studied.When there are large numbers of groups in the network, the state scalability is one of the most critical issues that delay the deployment of multicast. Forwarding state will increase linearly with the number of groups. Growing number of forwarding state entries means more memory requirement and slower forwarding process. Aggregated Multicast is a new technology; it aims to force multiple multicast groups to share one distribution tree in an intra-domain. This way, the number of trees in the network may be significantly reduced, consequently, forwarding state is also reduced, and thus the performance of Multicast network can be highly heightened.In this paper Multicast Protocols and the main application of Multicast are first discussed. The main objects and functions in NS-2 and how to add new protocol are analyzed. Furthermore the stochastic network topology...