A Statistical Bandwidth Sharing Perspective on Buffer Sizing

The issue of buffer sizing is rightly receiving increasing attention with the realization that the bandwidth delay product rule-ofthumb is becoming unsustainable as link capacity continues to grow. In the present paper we examine this issue from the light of our understanding of traffic characteristics and the performance of statistical bandwidth sharing. We demonstrate through simple analytical models coupled with the results of ns2 simulations that, while a buffer equivalent to the bandwidth delay product is certainly unnecessary, the recently advocated reduction to a few dozen packets is too drastic. The required buffer size depends significantly on the peak exogenous rate of multiplexed flows.