Design And Application Of Heuristic Application Layer Multicast Based On Central Strategy

Application layer multicast developed in recent years which inherits some characteristics of traditional IP multicast, won't depend on the support of multicast routers due to performing on end hosts and transporting data with IP unicast in network layer, so it avoids the fatal drawbacks successfully which obstruct the development of IP multicast and begins to being applied widely.This dissertation introduces some of main application layer multicasts first, compares and analyzes the performance of them in detail. Secondly, it discusses two general application layer multicast route problems, two greedy heuristics algorithm and protocol design principles. Based on the characteristics of present application layer cast systems, it provides a new application layer multicast—CALM which adapts communications with multiple senders and can maintain several multicast group with middle size number of members synchronously. This protocol uses central strategy and lowers control load with monitoring between the members of multicast session group. For the problem of excessively depending central controller, we use the way of redundancy controllers to solve it. Furthermore, we design a heuristic to balance delay and bandwidth efficiently. The simulation experiment shows that CALM multicast tree is close to IP multicast tree in efficiency. Finally it discusses an application of CALM that application can reduce the mount of data transported between nodes efficiently to lower bandwidth use by using audio merging technique in audio conference with multiple senders over CALM.The new application layer multicast provided in this dissertation, combined with some characteristics of main application layer multicast, is a solution with quick deployment, simple setup, easy access control and has done some work in application.