The FB-RED algorithm for TCP over ATM

We present the FB-RED (fair-buffering random early detection) algorithm, a new congestion control scheme for TCP over ATM connections which takes advantage of ATM to improve the fairness characteristics of the RED gateway algorithm. Utilizing the fact that ATM is connection-oriented and the ABR explicit rate control mechanism, the FB-RED algorithm calculates the bandwidth-delay product of each connection and based on this value it ensures fair drop probabilities. Two variants of the FB-RED algorithm are presented. The first one weighs the drop probabilities of the original RED algorithm relative to each connection's bandwidth-delay product, while the second one changes the original RED algorithm to ensure that the drop probabilities of each connection roughly equals the optimal drop probability. Both variants are shown to markedly improve the fairness as compared to the original RED algorithm in various simulation topologies.