基于线性规划的Internet端到端时延的估计

Linear Programming Based Estimation of Internet End-to-End Delay

测量Internet端到端时延特征是研究Internet端到端分组行为的重要内容之一,它能够应用于QoS(Quality of Service),SLA(Service Level Agreement)的管理、拥塞控制算法研究等许多方面.常用的端到端时延测量方法大多依赖于GPS接收机或采用NTP协议来实现收发端时钟的同步,但由于GPS接收机价格较高不可能每台主机都能配备, NTP协议的精度不能满足要求。该文基于线性规划的方法估计收发时钟的频差、相对时钟偏差等参数,以获得端到端时延的估计。作者在几条不同的链路上进行了测试,结果表明该方法能有效消除收发时钟不同步的影响。

This paper focuses on measurement of Internet end-to-end delay, which is one of the important characteristics of Internet end-to-end packet dynamics. Measuring the end-to-end delay of Internet can be used in QoS management, SLA management, congestion control algorithm development, etc. The conventional methods to measure one-way delay rely on GPS receiver or NTP protocol to keep synchronization between sender's clock and receiver's clock. However, GPS receiver is not ubiquitous in price and environment and NTP protocol is low in accuracy. A new method based on linear programming, which can remove the skew and offset between two clocks, is presented. Measuring results show that the method works well in removing the factors which effect the end-to-end delay measurement.