RMTP协议的时延分析

A Delay Analysis of RMTP

RMTP(reliable multicast transport protocol)是一种通过修复服务器(repair server)本地恢复来提供可靠性的组播协议.对改进的RMTP协议的时延性能进行建模分析.推导了数据包自发送主机发出到成功地被一个随机选择的接收主机接收之间的平均时延公式.分析表明,随着丢失率的增长,RMTP的时延性能恶化点将迅速下降;随着每个修复服务器下连接尾链路数量的增加,RMTP的时延性能恶化点也将下降.但是,随着尾链路总数量的增加而保持每个修复服务器连接的尾链路数量不变,RMTP的时延性能的变化很小.仿真结果较好地验证了分析的有效性.

RMTP is a reliable multicast protocol based on local loss recovery through repair servers. A delay modeling analysis of RMTP is presented, which derives the expression of average delay between the initial arrival of a packet at a sender and its correct reception at a randomly chosen receiver. The analysis results indicate that the saturated value of RMTP delay performance decreases rapidly under more loss environment. With the increasing of the number of tail links served by per repair server, the saturated value of delay also decreases. However, with the increasing of the number of total tail links while keeping the number of tail links served by per repair server constant, the saturated value of delay hardly changes. Finally, the analysis is confirmed by simulation results.