Research Of Multicast Based On Differentiated Service

With the development of network technology, there are various applications in the Internet. Many of them are multimedia applications, which cause many problems such as massive bandwidth consuming, network congestion. To solve these problems, multicast technology, which uses bandwidth effectively, is proposed. On the other hand, since multimedia applications increased, how to provide quality of service in IP network has become an important and realistic issue. DiffServ as the first choice for QoS model has become a research highlight. While multicast and DiffServ are used in a large scale, the combination of them will most likely become a trend. Due to the simplicity of the DiffServ design model, the combination will introduce some new problems. To resolve them, some solutions are put forward, which have high cost and low scalability.This thesis begins with the basic concept of multicast, describes the principles, merits together with flaws of most IP multicast routing protocols. By explaining the design idea, it presents function module of DiffServ and traces the process. It analyzes in detail problems of Neglected Reservation Subtree and Heterogeneous Multicast Groups while combining multicast and DiffServ. Then it adopts the receiver-driven idea, and brings forward Receiver-driven Based Re-mark Management Mechanism. In this mechanism, forwarding nodes know the receivers' QoS requests clearly by means of re-mark and admission control, and the two problems mentioned above are solved efficiently. Finally, it gives simulation results in NS, which proves RBRMM is one solution with low cost and high scalability.