Performance of TCP/IP over ABR service on ATM networks

The Available Bit Rate (ABR) service has been developed to support data applications over Asynchronous Transfer Mode (ATM). It is hence interesting to study the performance of reliable data transport protocols like the ''Transport Control Protocol (TCP)'' over ABR. We study the effect of running large unidirectional file transfer applications on TCP over ABR with an explicit rate algorithm (ERICA) implemented at the ATM switches. The paper shows that it is possible to get maximum TCP throughput when there are enough buffers at the switches. However, when the number of buffers is smaller, there is a large reduction in TCP throughput even though the Cell Loss Ratio (CLR) is very small. We study the effect of various factors which affect TCP throughput and fairness. These factors include the TCP timer granularity, switch buffering, ABR parameters, and the cell drop policy at the switches.