Research On Congestion Control For Multicast Based On Active Networks

Development of network techniques and application requirements promotes the research of high performance networks. There are three hotspots in current network research, including service customization, quality of service and security. The basic characteristics of high performance network are service customization, resource control and user management which are long-term questions that high performance network is confronted with. Multicast congestion control based on active network was researched with multimedia multicast application background.Firstly, based on analysing traditional Internet architecture and its protocols, active network architecture and active network service model was researched. Focusing on multimedia multicast applications, basic problems of multicast congestion control are researched, including multicast, single-rate multicast, and layered multicast techniques. An active network-based layered multicast service model was proposed, including Active Network Encapsulation Protocol(ANEP), active label layered mechanism and priority layered transmission mechanisms. A framework model of the active layered multicast service was proposed. Message Sequence Charts(MSC) was used as a formal method to subscribe the protocol mechanisms of senders, receivers and intermediate nodes. This is the theory base of the active layered multicast congestion control.Secondly, the key techniques of the active network-based layered multicast were researched. Hop-by-hop feedback control mechanism, hop-by-hop interactive signalling, TCP-friendly available bandwidth measurement, and active rate control mechanisms and algorithms were proposed. The key mechanisms and algorithms for the adaptive active layered multicast congestion control scheme were proposed and were researched deeply.Thirdly, three typical active layered multicast congestion control schemes were proposed. Active layered multicast service model integrates active label layering and priority layered transmission mechanism. ANLMCC scheme uses active congestion detection and release mechanism and hop-by-hop interactive signalling mechansim. HTALM uses hop-by-hop TCP-friendly available bandwidth measurement and active rate control mechanisms and algorithms. DL-AALM scheme uses adaptive utility layering policy and hop-by-hop feedback merging algorithms. The proposed protocol mechanisms and algorithms were researched deeply through simulation experiments. These schemes proposed are very usable and valuable to solve the problems of layered multicast congestion control in existing Internet.Lastly, An active network-based layered multicast congestion control prototype system were designed and implemented. These systems are service customization model based on component. The frameworks of the systems are presented in details. Then, implementation of the active layered multicast congestion control mechanisms and algorithms were researched based on these systems.Active network-based layered multicast congestion control problems are focused on and some research conclusions are achieved. These research conclusions can be applied to the new generation network service architecture and multimedia layered multicast congestion control, and have great reference value to the farther research.