一种新的TCP拥塞窗口动态调整策略  

A New Dynamic Adjustment Strategy of Transmission Control Protocol Congestion Window

作　　者：茹新宇[1,2] 刘渊[1] 

机构地区：[1]江南大学数字媒体学院,江苏无锡214122 [2]江苏联合职业技术学院无锡交通分院,江苏无锡214151

出　　处：《河南科技大学学报（自然科学版）》2018年第3期45-50,共6页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(61602213);江苏省自然科学基金项目(BK20151131)

摘　　要：为了缓解拥塞控制中加增乘减算法存在的系统吞吐量及带宽利用率偏低症状,提出了一种新的可靠传输层拥塞窗口调整策略。通过对往返延迟时间采样,构建正态分布函数,据此动态更新拥塞窗口,以适应网络实时变化的特点。并从数学角度对新策略及其算法的合理性与可行性进行了分析证明。实验结果表明:新算法相比于原New Reno算法和TCP Westwood算法,拥塞窗口均值分别提高2.25%和3.68%,丢包数则分别降低5.77%和7.43%。同时,对系统吞吐量和带宽利用率也有提升作用,系统吞吐量分别增加了3.09%和9.25%,带宽利用率分别增加了4.46%和1.37%,效果显著。To relieve low system throughput and bandwidth utilization rate in additive-increase-multiplicativedecrease algorithm of congestion control,a new reliable congestion window( cwnd) adjustment strategy was proposed. A normal distribution function was built by sampling the round trip delay time,which adapts to the real time network according to updating cwnd dynamically. The reasonability and feasibility of the new strategy and its algorithm was analyzed and proved from the view of mathematics. The results show that compared with original New Reno algorithm and TCP Westwood algorithm,the average value of cwnd of the new algorithm increases by 2. 25% and 3. 68%,and the packet loss rate decreases by 5. 77% and 7. 43%,respectively.Meanwhile,the system throughput and the bandwidth utilization rate are promoted. The system throughput increases by 3. 09% and 9. 25%,and the bandwidth utilization rate increases by 4. 46% and 1. 37%,respectively. The effect of the new strategy is significant.

关 键 词：拥塞窗口 策略 往返延迟时间 拥塞避免 慢启动门限阈值 

分 类 号：TP393.04[自动化与计算机技术—计算机应用技术]