基于NewReno拥塞控制机制的TCP分组乱序影响分析  

An Analysis of the Effect of the TCP Segment Reordering Based on the NewReno Congestion Control Mechanism

作　　者：胡晓峰[1] 孙志刚[1] 苏金树[1] 

机构地区：[1]国防科技大学计算机学院,湖南长沙410073

出　　处：《计算机工程与科学》2009年第5期8-12,共5页Computer Engineering & Science

基　　金：国家自然科学基金资助项目(90604006);国家973计划资助项目(2003CB314802)

摘　　要：报文乱序是互联网中普遍存在的现象,深入理解互联网报文乱序的行为属性和影响,对于设计高性能网络协议和新型网络设备体系结构、优化网络整体效能具有重要的意义。本文建立了NewReno拥塞控制算法的工作模型,通过实验验证了模型的有效性。基于该模型,分析报文乱序对TCP连接的影响,发现乱序报文对TCP连接吞吐率的影响显著,而且乱序报文的影响与报文丢失率紧密相关:当报文丢失率较低时,报文乱序会导致TCP连接的吞吐率急剧下降;当丢失率较高时,报文乱序的影响比较小。这些结论可为报文乱序友好的网络协议和新型网络设备体系结构的设计提供指导。Packet reordering is a common phenomenon in the Internet. Understanding the behaviors of packet reordering and its effects is helpful to designing high-performance network protocols and new network device architectures, and optimizing the Internet efficiency. This paper establishes a working model of the NewReno algorithm, and quantitatively analyzes the effects of packet reordering on the TCP throughput. The effect of packet reordering is remarkable and related to the packet loss rate. If the packet loss rate is low, reordering degrades the performance of TCP connections significantly. With the increase of the packet loss rate, the performance degradation gets much less. These findings should be instructive in the design of packet-reordering friendly protocols and new network device architectures.

关 键 词：NewReno 拥塞控制 报文乱序 

分 类 号：TP393.03[自动化与计算机技术—计算机应用技术]