Simulating flow level bandwidth sharing with pareto distributed file sizes

Our goal is to achieve deeper understanding of the limitation of queueing models, on one hand, and of common simulation practice, on the other hand, as tools for predicting performance of bandwidth sharing between competing TCP flows. In particular, we (i) present an overview of simulation problems that are expected to arise due to the very heavy tail of the distribution of the size of TCP flows, and (ii) through simulations we show that the average sojourn time of competing flows are quite sensitive to various network parameters. The understanding that we get from the first point allows us to better assess when are the conclusions from simulation results on bandwidth sharing reliable. Using simulations in ns2, we study bandwidth sharing under various load factors and show the benefit of using bootstrap as a post simulation tool for analyzing the simulation results.