基于高精度性能计数器的网络单向时延研究

Research on One-way Delay of Network Based on High-resolution Performance Counter

区别于常规的消除时钟偏差和时钟频差的网络单向时延测量方法,提出一种新的单向时延测量方法.利用两主机的高精度性能计数器的相对关系,推导出基于高精度性能计数器的网络单向时延表达式,为了估算表达式中的待定项,在两主机之间建立TCP连接,周期性双方向交换性能计数器信息,通过包对理论,定时更新时延表达式中的待定项.结果显示,该方法完全不需要主机之间的时钟同步,具有精度高、可在线测量的优点,同时,它提供了一种非对称网络环境下单向时延测量的手段.

A novel measurement approach for one-way delay is proposed,which is different from conventional measurement based on some assumptions to remove clock offset and skew. Expression of one-way delay is derived from relative relationship between two hosts based on high-resolution performance counter. TCP connection between two hosts is established in order to evaluate the unknown parameter in the delay expression. Values of the performance counter are exchanged in both directions periodically,and the unknown parameter in the delay expression is updated timing by using packet pair theory. The result shows that clock synchronization is not required in the algorithm entirely,and the algorithm has the advantage of high precision and can be measured online. Meanwhile,the algorithm is suitable for measurement in the case of network with asymmetric structure.