In this paper we describe an analytical technique for the performance evaluation of wide-area networks carrying realistic TCP traffic, such as that produced by a large number of finite-sized connections transferring files whose sizes are taken from a long-tail distribution. The analytical predictions are validated against detailed simulation experiments, and prove to be accurate and robust under a variety of operating conditions. The model also provides original insights into the impact on the network of long-tail flow length distributions, and allows the effectiveness of "TCP pacing" in reducing the traffic burstiness to be evaluated analytically. Our contribution is a performance evaluation methodology that could be usefully employed in network dimensioning and engineering. c 2007 Elsevier B.V. All rights reserved.
Michele Garetto, Donald F. Towsley