一种改进的TCP拥塞控制算法的公平性研究  

An Improved Version of TCP Congestion Control Algorithm and Its Fairness Evaluation

作　　者：曾晓红[1] 漆丽娟[1] 谢树云[1] 

机构地区：[1]昭通师范高等专科学校计算机科学系,云南昭通657000

出　　处：《计算机仿真》2010年第4期120-124,共5页Computer Simulation

摘　　要：针对提高网络资源利用率,对TCP Reno拥塞控制算法进行改进,为实施拥塞优化控制,提出一种改进的拥塞控制算法。为判断该算法对所有数据流是否公平,在对其正确性和公平性进行理论分析后,构建NS2仿真模型并进行仿真,由于仿真结果数据量大,常规方法分析较为困难,故将仿真结果转换为数据库文件进行分析,该方法可操作性强,具有速度快,精度高,自主性强等优势;通过丢弃分组数的方差比较TCP Reno算法和改进算法在丢弃分组上的差异,通过延迟和延迟抖动标准差比较延迟和延迟抖动在不同数据流中的差异,上述参数更能从全局上反映多个比较项之间的整体差异。通过理论分析和仿真结果对比,该改进算法对于各数据流是公平的,且与TCP算法的公平性相当。In order to increase the efficiency of network resources, an improved algorithm of congestion control was suggested. Through theoretical analysis, a NS2 model was built and implemented. There are a lot of simulation data, so it is very difficult to find the essence of the simulation model by conventional method. So the simulation re- sult was converted to data table for deep analysis. This method enhances the autonomy of simulation analysis and is easy to implement with the advantages of high speed and high precision. The differences of in every data flow were compared by delay and jitter standard deviation and the differences of TCP Reno algorithm and the improved algorithm in dropping packets were compared by dropping packets variance. A conclusion was drawn that the improved algo- rithm is fair for all the source nodes during congestions and is an equivalent to ordinary TCP congestion algorithm.

关 键 词：传输控制协议 拥塞控制 网络仿真器 公平性 

分 类 号：TP393.04[自动化与计算机技术—计算机应用技术]