一种改进的TCP连接初始阶段的拥塞控制模型

本文对TCP连接初始阶段的拥塞控制模型加以改进,以避免初始阶段大量丢包现象的发生.在改进模型中,发送方根据最初收到的ACK动态估计网络可用带宽,并以此计算初始的慢启动阈值ssthresh,并将拥塞发生后的ssthresh调整为网络数据包总长度的3/4.本模型包含慢启动、拥塞避免、快速重传和快速恢复四个阶段.最后,我们的测试结果表明了改进的模型获得了更好的性能.

A Refined Congestion Control Scheme for Initial TCP Connection

This paper proposes changes to the congestion control scheme to avoid lots of lost packets in a window during the start up period of a TCP connection. In our improved scheme,the sender dynamically calculates the bandwidth using the acknowledgments originally received. Thus,a more appropriate ssthresh can be got for TCP initial connections. We also adjust the ssthresh to three quarters of the outstanding segments. This scheme includes four phases which are Slow Start,Congestion Avoidance,Fast Retransmit and Fast Recovery.The test results show that the refined scheme achieves better performances.