TCP BUFFERING AND PERFORMANCE OVER AN ATM NETWORK

This paper reports a series of experiments to measure TCP performance when transferring data through an asynchronous transfer mode (ATM) swi tch, The results show that TCP buffer sizes and the ATM interface maxi mum transmission unit have a dramatic impact on throughput. We observe a throughput anomaly iu which an increase in the receiver's buffer si ze decreases throughput substantially. For example, when using a 16K o ctet send buffer and ATM Adaptation Layer 5 on a 100 megabit per secon d (Mb/s) ATM path, the mean throughput for a bulk transfer drops from 15.05 Mb/s to 0.322 Mb/s if the receiver's buffer size is increased fr om 16K octets to 24K octets. This paper analyzes the performance, expl ains the anomalous behavior, and describes a solution that prevents th e anomaly from occurring.