An Architecture for Scalable QoS Multicast Provisioning

IP multicast suffers from scalability problems as the number of concurrently active multicast groups increases, since it requires a router to keep forwarding state for every multicast tree passing through it. In QoS multicast provisioning, the problem becomes even worse, since not only the forwarding state but also the resource requirement of a multicast group needs to be kept at the router. Previously, we proposed and evaluated a novel scheme called aggregated multicast to reduce multicast state. In this report, we present an architecture, called aggregated QoS multicast(AQM), for scalable QoS multicast provisioning. In this architecture, we examine how we can use aggregated multicast to support QoS multicast efficiently in Diff-Serv-Supported MPLS networks. QoS Multicasting is a multifacet problem, involving routing, admission control, resource management and other related issues. In AQM, we provide efficient and practical solutions for those issues. AQM is scalable, especially for QoS multicast provisioning in transit domains. Our design shows that AQM is feasible and implementable based on MPLS and Diff-Serv techniques. With the increasing demand of interactive, real-time applications, such as videoconferencing, sportcasting, workgroups, internet games etc., AQM appears to be a very simple, attractive solution for scalable, real-time QoS multicast services in the Internet.