Observing TCP dynamics in real networks

The behavior of the TCP protocol in simple situations is well-understood, but when multiple connections share a set of network resources the protocol can exhibit surprising phenomena. Earlier studies have identified several such phenomena, and have analyzed them using simulation or observation of contrived situations. This paper shows how, by analyzing traces of a busy segment of the Internet, it is possible to observe these phenomena in real life and measure both their frequency and their effects on performance. A TCP implementation might use similar techniques to support rate-based congestion control.