摘要:在了解了Internet中存在的的网络拥塞现象及其产生的本质后，本文对所研究的课题进行了需求分析以及可行性分析，然后介绍了拥塞控制策略的发展及研究现状，分析了目前存在的问题，并在此基础上提出了改进算法——一种结合使用历史连接参数和令牌技术的改进算法，该算法在建立新连接时通过查找缓存的历史记录初始化拥塞参数，使用令牌技术将数据包在第1个RTT时间内均匀发送，并在传输过程的适当时刻将连接的拥塞参数保存在缓存中。本研究需要借助网络仿真器NS2来实现仿真，NS2作为当今网络模拟器中的佼佼者，发挥了举足轻重的作用。最后介绍了NS2的基本构成，使用方法。结尾的仿真分析能够很好的验证典型的三个TCP拥塞控制算法的正确性。
关键词:TCP 拥塞控制 慢启动 拥塞避免 回路响应时间 拥塞窗口 慢启动阈值 TCP Reno 公平性问题 HCTCP
毕业设计（论文）外文摘要
Title The research of network congestion control
Abstract:After the network congested phenomenon of the ones that exist and essence produced in understanding Internet, this text has carried on demand analysis and feasibility analysis to the subject studied, then introduced the development of the congested control strategy and study the current situation, has analysed the existing problem at present, and has proposed improving algorithms on this basis -- A kind of combination uses history to connect the improvement algorithm of the parameter and making brand technology, algorithm this while setting up new connection through find out history of the buffer memory writes down and initializes the congested parameter, use making brand technology to wrap up the data within 1st RTT time to send evenly , and keep the congested parameter joined in the buffer memory at the proper moment of the transmission course. This research demand asks for help the network imitates the true machine NS2 to realize to imitate true, NS2 conduct and actions now network in the emulator, developed the prominent function. Introduced the NS2 finally basic to constitute, operation method. The knot tail imitates true analysis can three TCP of the good verification typical model obstruct the accuracy that control the calculate way.
Keywords TCP; congestion control; slow start; congestion avoidance; RTT; cwnd; ssthresh; TCP Reno; Fair problem; HCTCP
