一种异构网络TCP拥塞控制算法

TCP Congestion Control Algorithm for Heterogeneous Networks

针对互联网中端对端带宽、时延和丢包率等的差异性日益加剧,导致TCP传输性能严重退化,该文提出一种链路自适应TCP拥塞控制算法(INVS)。INVS在拥塞避免阶段初期采用基于指数函数的凸窗口增长函数,以提高链路利用率;在窗口增长函数中引入了自适应增长因子实现窗口增长速率与链路状态相匹配;采用了自适应队列门限的丢包区分策略以提高无线环境下TCP的性能。性能分析和评估表明,INVS提高了TCP拥塞控制算法的吞吐量、公平性、链路利用率和RTT公平性。

The end-to-end bandwidth, the Round Trip Time（RTT） and the packet loss rate vary over many orders of magnitude in Internet, which cause significant performance degradation of Transmission Control Protocol（TCP）. To cope with this, a path-adaptive TCP congestion control protocol, called INVerse Sigmoid（INVS）, is proposed. INVS employs an exponential function based convex growth function of congestion window to improve the path utilization. An adaptive increase factor in the growth function is introduced to match the window growth rate with the path condition. An adaptive queue-threshold in the loss distinguishing scheme is used to enhance the performance of TCP over wireless links. The performance analysis and evaluation show that INVS improves the throughput, the fairness, the total link utilization and the RTT-fairness of TCP congestion control algorithm.