拥塞窗口自适应的TCP拥塞避免算法

针对TCP Reno拥塞避免阶段拥塞窗口增长不够平滑的缺陷，在研究分析TCP Reno拥塞控制算法的基础上，提出一种基于拥塞窗口自适应调整增长因子的拥塞避免新算法——在拥塞避免阶段采用压缩特性的对数增长因子函数。在网络情况良好阶段，该因子增长速率大，以充分利用网络资源；而在逼近网络拥塞阶段，该因子以较小的速率增长，以避免过激的拥塞丢包。数学分析说明了新算法的可行性，并通过NS仿真对其吞吐量、公平性、友好性进行评估。仿真结果表明该改进的TCP拥塞避免算法的有效性。

TCP congestion avoidance algorithm based on adaptive congestion window

Concerning the unsmooth growth of congestion window at congestion avoidance phase of TCP Reno, the traditional AIMD algorithm was researched and an improved congestion avoidance algorithm was proposed: a logarithmic function based on the growth of congestion window was adopted. In this new algorithm, additive factor is usually increased quickly when the network is doing well and less so when network situation is getting to congestion. The mathematical analysis shows the feasibility of the new algorithm, and its throughput, fairness and friendliness were evaluated by NS simulation. The simulation results show the effectiveness of the algorithm.