The issue of buffer sizing is rightly receiving increasing at-tention with the realization that the bandwidth delay product rule-of-thumb is becoming unsustainable as link capacity continues to grow. In the present paper we examine this issue from the light of our understand-ing 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 band-width delay product is certainly unnecessary, the recently advocated re-duction to a few dozen packets is too drastic. The required buffer size depends significantly on the peak exogenous rate of multiplexed flows.