Correlation of Packet Delay and Loss in the Internet 1

In this paper we examine the correlation between packet delay and packet loss experienced by a continuousmedia traffic source on the Internet. Our goal is to study the extent to which one performance measure can be used to predict of the future behavior of the other (e.g., whether observed increasing delay is a good predictor of future loss) so that an adaptive continuous media application might take anticipatory action based on observed performance. We ran numerous hour-long experiments in which continuous media traffic was sent from a source to a destination. We measured the per-packet delay and packet loss and then analyzed our measurements off-line. Our results provide a quantitative study of the extent to which such correlation exists. Interestingly, we observe periodic phenomena in the correlation that we had initially not expected. We discuss our results, speculate as to the reason for the observed behaviors, and discuss their implications for adaptive continuous media applications. 1