一种高效通用的TCP尾部丢包恢复算法  

Efficient Universal Tail Loss Recovery Algorithm for TCP

作　　者：张旭[1,2,3] 顾乃杰[1,2,3] 谷德贺 刘博文[1,2,3] 苏俊杰[1,2,3] 

机构地区：[1]中国科学技术大学计算机科学与技术学院,合肥230027 [2]安徽省计算与通信软件重点实验室,合肥230027 [3]中国科学技术大学先进技术研究院,合肥230027

出　　处：《小型微型计算机系统》2017年第9期1921-1927,共7页Journal of Chinese Computer Systems

摘　　要：随者互联网时代的到来,如何提升互联网应用的交互性能逐渐成为时下的研究热点;而在当今的互联网环境中,网络带宽已经不是瓶颈,网络时延成为影响应用交互性能的关键因素.作为互联网时代的主要应用,Web应用的网络时延受到TCP尾部丢包现象的严重影响.Tail Loss Probe算法是一种通过发送探针包来触发恢复的高效易部署的TCP尾部丢包恢复算法,但其需要修改现有的TCP加速机制,存在影响互联网稳定性的风险.针对Tail Loss Probe算法存在的不足,提出一种Double Tail Loss Probe算法,该算法对不同的尾部丢包模式进行细化处理且在适当时机下发送两个探针包以加速恢复并实现与现有TCP机制的友好兼容,从而保证互联网数据流通的稳定性.实验表明,在不同的丢包粒度和传播时延下,Double Tail Loss Probe算法都展现出更快的恢复速度;尤其在丢包粒度较大时,相比Tail Loss Probe,该算法取得了约20%的性能提升.As the era of Internet comes,the interactive performance of Internetbased applications becomes a research hotspot.In the current Internet,bandwidth is not the bottleneck anymore and network latency becomes a key factor that impacts user experience.As an important type of Internetbased applications,Web applications are severely influenced by the tail loss phenomenon of TCP.Tail Loss Probe is an efficient and easy-to-deploy tail loss recovery algorithm which transmits one probe to trigger other recovery mechanisms,but this algorithm requires modifications to other existing TCP mechanisms and thus incurs instability to the Internet.Based on Tail Loss Probe,this paper proposes a more efficient algorithm,Double Tail Loss Probe,which addresses different types of tail loss with different methods and sometimes transmits two probes to accelerate loss recovery.Double Tail Loss Probe is well compatible with existing TCP mechanisms and hence maintains the Internet stability.Through extensive experiments,Double Tail Loss Probe shows faster recovery speed under various loss degrees and propagation delays;especially,under the scenarios with large loss degrees,it achieves about 20% performance promotion when compared with Tail Loss Probe.

关 键 词：TCP 尾部丢包 丢包恢复 Web时延 互联网性能评测 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]