An Improved Vegas Algorithm for Enhancing Compatibility with TCP Reno
Hui Gary Zhang · Journal of Air Force Engineering University · 2010
TCP Vegas can provide a better performance compared to the traditional TCP Reno scheme.However,when TCP Vegas and TCP Reno connections coexist and share the same link in wired network,there exists a serious incompatibility problem of unfair bandwidth sharing in favor of TCP Reno.To solve this problem,by adding monitoring algorithm of the network state based on relative queuing delay to TCP Vegas-A,an enhanced Vegas algorithm is proposed,termed TCP Vegas-A+.TCP Vegas-A+ can adjust the congestion window more properly and timely by classifying the network state into congestion increase and congestion decrease.We analyze the compatibility of Vegas-A+ and Reno connections by computing and comparing the congestion window size and the number of transmitted packets in congestion avoidance phase,and compare it with the compatibility of Vegas+ and Reno connections.Mathematical analysis and simulation results show that,TCP Vegas-A+ algorithm improves the compatibility with TCP Reno and has a better capacity in competition with the Reno for bandwidth than other improved Vegas algorithms.