Research On Congestion Control Of Multicast

With the Internet spreading fast in the world, the increasing of network applications, especially multimedia applications, makes the usual approaches and methods of congestion control no longer suitable for the new environment. Moreover, special network environment and application also need particular congestion control technique's support. The purpose of congestion control is congestion avoiding by controlling of input traffic to reach a kind of tradeoff. This state is described as a balancing situation between avoiding loss of packets and high throughput of network. But up to now, the stability of system, especially the oscillation of buffer occupancy hasn't been the focus in research of congestion control. If the system is not stable, the packets' loss can't be avoided because of oscillation. Moreover the system can quickly use the increasing available bandwidth and the throughput of network is increased.With regard to the flow regulation of multicast flow in high-speed computer communication networks, the thesis proposes a class of sender-driven single rate congestion controllers based on single-to-many multicast model. Based on system stability, especially Schur-Cohn and Routh-Hurwitz criteria, it is shown the controller can regulate the source rate on the basis of the knowledge of buffer occupancy of the destination node in such a manner that (1) the rate of source node is stable; (2) the congestion controlled network is asymptotically stable without oscillation in terms of the buffer occupancy of the destination node; (3) it satisfies the condition of fairness in multicast.We have fulfilled a variety of simulations under various traffic conditions and network environment. They show good performance of the proposed congestion control schemes.