The Analysis And Application Study Of Multicast Routing Protocols

Along with the further research and extension on Multicast technique, the standard of IP Multicast is developing to manageable Multicast among the Internet. Owing to the daily urgent needs on the arrangement and implementation of Multicast in the network of various scales, the analysis and application about Multicast routing protocols are especially important. This essay compared and studied all kinds of current Multicast routing protocols, carried experiments on some key techniques through the arrangement of Multicast services in local area network. After comparing the merit and shortcoming of the three kinds of location methods of the RP (Rendezvous Point) of PIM-SM, we studied the PIM-SM working mechanisms and realization mechanisms in detail. During the research procession, we discovered that the RP node, acting as the root of shared tree, plays an important roll in the forward multicast packets. How to select the node of RP is very important to the realization of the Protocol, but PIM-SM itself did not offer us any ways to select RP. Therefore, we introduced a new extending protocol EPIM-SM (extend to PIM-SM), which is based on PIM-SM. This protocol adopts a new algorithm to replace the hash algorithm, a method used by PIM-SM to select RP. It offers a mechanism: According to the the topology of the network, and the changing situation of sources and members, estimate the multicast tree' s total cost for each candidate RP, and select a minimized cost RP periodically. If the RP can make the decrease bigger than a pre-defined threshold,q, it can be selected as the new RP of the multicast tree, and sources and members will be informed to join the new RP so as to keep the cost of multicast tree continuously near to the lowest point.Our research accumulated theoretical and practical experiment for the further arrangement multicast services in large scale campus network, and offered software and hardware platform for further research.The study method of this essay is to build experiment platform, to apply node to nodes method under experimental platform, this includes the application of information push, management advice, program broadcast, and make experiments on key technology of Multicast arrangement, and offer a realizable program for campus network arrangement Multicast on the bases of the research conclusion.At last, we made a conclusion on our study, and point out the shortcoming of the essay and the direction of further study.