基于异构网络的TCP Vegas拥塞控制算法改进研究  

Research on Improvement of TCPVegas Congestion Control Algorithm Based on Heterogeneous Network

作　　者：张奎 刘晨 Zhang Kui;Liu Chen(School of Computer Science and Technology,Kashi University,Kashi,Xinjiang 844006,China)

机构地区：[1]喀什大学计算机科学与技术学院,新疆喀什844006

出　　处：《伊犁师范学院学报（自然科学版）》2021年第2期56-61,共6页Journal of Yili Normal University：Natural Science Edition

基　　金：新疆高校科研计划资助项目(XJEDU2019Y041);喀什大学校内课题((2020)2738,(2020)2704).

摘　　要：针对异构网络在传输较大数据包时,Vegas算法根据RTT(Round-TripTime,往返时延)超时来判定网络发生了拥塞,进而采取拥塞控制措施,而实际网络并没有发生拥塞的问题,在分析Vegas算法和队列管理机制工作原理的基础上,提出一种改进的Vegas跨层拥塞控制算法.该算法网络层采用RED队列管理机制,通过调节阈值参数和链路窗口满足一定的比例关系时,中间节点能够及时调度、处理和分发分组数据并降低RTT值,避免网络进入拥塞控制阶段,实现Vegas与Reno算法共存时的拥塞控制.NS2仿真结果表明,改进算法具有大拥塞窗口、高吞吐量和低误码率的性能,与Reno算法共存时网络性能较好,从而验证了改进算法的有效性.When a heterogeneous network transmits large data packets,the Vegas algorithm determines that the network is congested according to the RTT(Round-Trip Time)timeout,and then takes congestion control measures.However,the actual network does not have a congestion problem.On the basis of analyzing the working principle of Vegas algorithm and queue management mechanism,an improved Vegas cross-layer congestion control algorithm was proposed.The network layer of this algorithm adopts the RED queue management mechanism.By adjusting the threshold parameters and the link window to meet a certain proportional relationship,the intermediate node can schedule,process and distribute packet data in time and reduce the RTT value,avoiding the network entering the congestion control stage,and realizing Vegas and Congestion control when Reno algorithm coexists.NS2 simulation results show that the improved algorithm has the performance of large congestion window,high throughput and low bit error rate,and the network performance is better when coexisting with the Reno algorithm,thus verifying the effectiveness of the improved algorithm.

关 键 词：拥塞控制 队列管理机制 往返时间 拥塞窗口 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]