EPD+: a new packet discard mechanism to improve TCP performance over ATM-UBR

A new packet discard scheme called the forgiveness mechanism that can be plugged into the existing buffer management schemes to remarkably enhance throughput and fairness of TCP running over ATM-UBR service is developed. Our scheme does not require per VC accounting but per VC-state where only one bit is needed. Our focus is on demonstrating and analyzing the effect of the forgiveness mechanism when plugged into the EPD scheme in low latency networks. The EPD scheme is selected because it is a simple management policy that can be practically applied to existing ATM switches. This paper describes the concepts behind the new scheme and demonstrates its effect on TCP performance.