Research Of Hierarchical-ring Application Layer Multicast Model Based On Differentiated Services

With the rapid development of multimedia and communication technology, Internet has become the most important way to acquire the information for people. Although the CPU of the network equipments become more quickly and the bandwidth of networks continue increasing, the networks can not satisfy the increase of application requirement. Unicast can hardly meet this kind of applications well. Up to now, unsolved issues in IP multicast service model and protocol prevent it from widely deployment. Then people turn to other alternative technologies, among which is application layer multicast.In application layer multicast, multicast functions are moved from routers to end systems. End system is used to realize all communicate functions of multicast group, for example, the construction of multicast tree, copy and distribute of data packet and so on. All group members set up an overlay network on top of IP network and construct multicast tree in it. In this way, it disposes the bundle of depending on routers which traditional IP multicast must be need, computing resource are fully excavated and all kinds of functions can be added flexibly.After reading plenty of literature and analyzing relative protocols of application layer multicast which have been proposed thoroughly, we proposed a new multicast model named HRMDS (Hierarchical-ring application layer multicast model based on Differentiated Services). In this thesis, we discusses the construction of model, work and routing mechanism in detail and also describes the creation of multicast group, the join and quit process of members and the dispose of node failure.HRMDS protocol uses hierarchical-ring structure, the data can be transmitted between layers and within the ring simultaneously, and its also uses reputation mechanism. Accounting to periodically algorithm, we can select the node with the highest reputation as the leader of ring. Using a special routing algorithm, we can transmit different types of data with different strategies. Simulation results show that the protocol can adapt to real-time and non real-time business scenarios, and has good end to end delay and link stress, has a very good prospect of application.