Improving RED algorithm performance in ATM networks

Supporting TCP data traffic over ATM-UBR service class requires special mechanisms to improve the throughput and fairness while minimizing the delay. Several ATM buffer management schemes have been proposed to improve the throughput and fairness for a selective drop: early packet discard (EPD) and fair buffer allocation (FBA). Concurrently, the RED (random early detection) algorithm proposed for packet networks (including IP) avoids, by the packet marking mean, the global synchronization of TCP sources while maintaining a high throughput and low delay. We study the adaptation of the RED algorithm to ATM (using EPD) and introduce an algorithm to improve its fairness. We propose and compare a cell based and a packet based RED algorithm. Finally we compare the performance of RED with EPD and pure EPD, in terms of the throughput, fairness and delay, in the presence of a background on/off source.