A simple passive method to estimate RTT in high bandwidth-delay networks

Abstract

This paper presents a simple passive algorithm to estimate the Round-Trip-Time (RTT) of a TCP connection in high bandwidth-delay network scenarios. In these scenarios, a passive RTT estimator that can be used on captured packet traces is a useful tool for performance analysis. The algorithm is based on observing periodic RTT patterns in a TCP connection that is not filling its bandwidth×delay product. The results are compared to other passive methods such as the RTT of initial TCP handshake or TCP Timestamp option samples. The algorithm is shown to be effective and may be used in more scenarios than other methods thus, it provides a valuable tool to improve the amount of TCP connection whose RTT can be measured in a captured packet trace.