QoS-Oriented Multicast Group Management Mechanism

Being widely deployed at present, Internet Multimedia application, such as IPTV, video conference, remote education and so on, will bring a new increase on business. As the most effective network transmission technology to carry such kinds of one point to multi point services, multicast only copies packets on necessary branches of network and saves the link bandwidth as much as possible. Therefore, research on multicast will play an important role on improving the quality of service of Internet multimedia application.As an indispensable part of multicast protocol family, Internet Group Management Protocol (IGMP) is used by router to collect group membership information of hosts attached, and then interactive with multicast routing protocol to get the multicast flows needed. However, user identification and QoS guarantee, which effect the deployment of multicast service, are ignored, so it's valuable to discuss QoS-oriented multicast management mechanism.This paper firstly introduces IP multicast technology and IGMP, analyses the principle of multicast simulation on ns2 which is a widely used network research software, then illustrates in details IGMP extension to ns2 which developed in this paper, and shows how to configure and use it in simulation. IGMP extension implements most of important features specified in RFC 3376, especially supporting source filtering, and passes entire functional testing. Therefore, IGMP module will facilitate research related to multicast on ns2 platform.Based the work above, the paper proposes a QoS-oriented group management solution. Taking collaboration between IGMP router and Rendezvous Point and exploiting flow monitor algorithms, the solution achieves group member admission mechanism with QoS guarantee, and assigns network resource reasonably among users according to defined policies. For illustrating its advantages, the paper implements the solution based on ns2, and carries out a simulation experiments compared the solution with standard IGMP. The results distinctly demonstrate the solution effectively avoids network congestion and makes multicast service more manageable.In a word, QoS-oriented group management solution proposed in this paper provides an extensible framework to realize scalar quality of multicast service by adding complex policies, and therefore has high practice value and will promote the deployment of multicast application.