On the distribution of round-trip delays in TCP/IP networks

TCP traffic round-trip delay measurements have been carried out in the Ericsson Corporate Network. Based on these data a comprehensive analysis has been performed to identify basic state changes in the network and to find the parametric distribution of the round-trip delay. The main finding of our research is that the round-trip delay can be well approximated by a truncated normal distribution. A method for parameter setting with the statistical tests for validation is also presented. Finally, we discuss the possible explanations of this result.