On link dimensioning based on estimating the mean rate by the sustainable rate

We attempt to quantify the extent to which using the sustainable rate as an estimate of the mean transfer rate results in the wastage of bandwidth. We treat users as on-off traffic sources with arbitrary on and off times, and use allocations based on Gaussian assumptions. We also confirm that this model is consistent with our intuitive understanding that estimating the mean by the sustainable rate should lead to a conservative estimate of the required bandwidth.