避免假重传使TCP更健壮的RR-CETEN算法  

RR-CETEN Algorithm: Making TC PMore Robust Against Spurious Retransmissions

作　　者：王东[1] 朱晓洁[2] 吴克寿[3] 张大方[1] 

机构地区：[1]湖南大学计算机与通信学院,湖南长沙410082 [2]北京航空航天大学计算机学院,北京100083 [3]湖南大学软件学院,湖南长沙410082

出　　处：《重庆大学学报（自然科学版）》2006年第9期115-121,共7页Journal of Chongqing University

基　　金：国家自然科学基金资助项目(60273070)

摘　　要：许多研究表明,在高并行度和不同链接速率的无线网和卫星网中都存在包的重排序.由于重排序将导致对网络拥塞过高的估计,它大大降低了网络的TCP性能.CETEN(Cumulative ExplicitTransport ErrorNotification)虽然解决了出错丢包对网络拥塞估计偏差的问题,但由于没有考虑无线网络下包的重排序情况,同时也使LEAST(Loss Estimations A lgorithmS for TCP)算法的丢包估计值不准确,导致出错丢包率产生偏差.为此,通过在接收方增加显式的假重传通告方案,使发送方不仅能区分丢失(出错和拥塞)的包,还能处理重排序包,提高了LEAST算法的精确度,使TCP更加健壮.试验仿真结果表明这种方法的有效性.Numerous studies have shown that packet reordering is common, especially at wireless and Satellite networks where there are high degree of parallelism and different link speeds. Packets reordering decreases TC Pperformance, because it leads to over estimation of network congestion. The CETEN（ Cumulative Explicit Transport Error Notification） has solved the overestimation caused by packet corruption. However, it does not consider the reordering at wireless network, which makes the LEAST（Loss Estimations Algorithms for TCP） loss rate value imprecise. The solution is based on explicit spurious retransmit notification at receiver side, and signals the sender packet loss caused by reordering packet. This mechanism can improve precision of LEAST and make the TC Pmore robust. The method is showed efficient in experiment.

关 键 词：重排序包 假重传 丢包 拥塞控制 

分 类 号：TP393.04[自动化与计算机技术—计算机应用技术]