Research On Multicast Congestion Control In Active Network

Internet has been in explosive development for the recent years, Many newapplications, especially large-scale multimedia systems and distant learningenvironments, which are based on reliable multicast, are being more widely deloyed.The congestion control for these application has become one of the most importantissues in network researchs so that the fairness and stability of future could be ensured.Although classic TCP congestion control algorithm plays an important role in thecurrent Internet, it is not suitable for the reliable multicast. so it needs to research anew multicast congestion control mechanism.TFRC algorithm, which proposed the equation of TCP average rate and a newrate based control strategy, indicates a new approach to congestion control for reliablemulticast. But TFRC algorithm can not be directed applied to multicast congestioncontrol, it must integrate with a new network technology. Active network provides aprogrammable network interface in network nodes. Active networks not only have thebasic capability of forward packets toward their destination as of a traditional packetnetwork, but alse have the capability to support dynamic modification of thenetwork's behavior as seen by user. A novel scalable architecture of active network innetwork simulation environment is given an implementd. On the base of analyzingActive network and TFRC schem, this dissertation provides a multicast congestionalgorithm on active network(An-TFRC). It realizes the idea of TFRC based on thecombine the TFRC's rate control mentality with the programmable mechanism ofactive network. Futuremore, it users the average weighted strategy to solve the issueof Drop-to-Zero.This dissertation designs and analyse the algorithm, and implements it in NSmodeling language. The experiment results reval thar this algorithm is an effectivemulticast congestion algorithm and has some practical use.