一种基于PGM的单速率组播拥塞控制方案

A PGM-Based Single-Rate Multicast Congestion Control Scheme

PGM(pragmatic general multicast)是一种在IP协议中广泛应用的可靠的组播传输协议.但PGM标准本身没有拥塞控制方案,不能实时响应网络需求,及时地调节源端发送速率.针对这个问题,在保证PGM协议可扩展性的基础上,在发送方与CLR(current limiting receiver)之间采用了一种新的闭环控制器来实时地调节源端的发送速率,使其逐渐趋于稳定,并具有较快的响应速度.而且在网络拓扑结构动态变化的情况下,对所提出的拥塞控制方案进行了仿真实验.仿真结果表明,所提出的算法具有较好的可扩展性、稳定性和较快的响应速度,控制方案使网络性能表现良好. PGM(pragmatic general multicast)是一种在IP协议中广泛应用的可靠的组播传输协议.但PGM标准本身没有拥塞控制方案,不能实时响应网络需求,及时地调节源端发送速率.针对这个问题,在保证PGM协议可扩展性的基础上,在发送方与CLR(current limiting receiver)之间采用了一种新的闭环控制器来实时地调节源端的发送速率,使其逐渐趋于稳定,并具有较快的响应速度.而且在网络拓扑结构动态变化的情况下,对所提出的拥塞控制方案进行了仿真实验.仿真结果表明,所提出的算法具有较好的可扩展性、稳定性和较快的响应速度,控制方案使网络性能表现良好.

PGM (pragmatic general multicast) is a reliable multicast transport protocol, which runs on IP networks. Because PGM standard does not include any congestion control scheme in itself, it can抰 achieve real-time response to satisfy the requirements of network and can抰 timely adjust the sending rate. Based on the PGM protocol, a novel close-loop controller, which is suggested to be implemented between the sender and the CLR (current limiting receiver), is introduced in this paper to timely adjust the sending rate. The proposed rate control scheme brings the source抯 sending rate of the network to be stable gradually and has fast response. Simulations are carried out for the proposed control scheme, and the simulation results demonstrate that the proposed algorithm has the following properties: scalability, stability, fast convergence, and fast response under various network environments. They show good performance of the proposed multicast control schemes.