Shiv Kalyanaraman , Performance of TCP over ABR on ATM backbone and with various VBR tra c patterns 1 Performance of TCP over

We extend our earlier studies of buuer requirements of TCP over ABR 10, 11, 12] in two directions. First, we study the performance of TCP over ABR in an ATM backbone. On the backbone, the TCP queues are at the edge router and not inside the ATM network. The router requires buuer equal to the sum of the receiver window sizes of the participating TCP connections. Second, we introduce various patterns of VBR background traac. The VBR background introduces variance in the ABR capacity and the TCP traac introduces variance in the ABR demand. Some simple switch schemes are unable to keep up with the combined eeect of highly varying demands and highly varying ABR capacity. We present our experiences with reening the ERICA+ switch scheme to handle these conditions.