We use a 15 minute section of a Squid proxy trace logged at UC Berkeley as the foreground traffic over L. The number of flows fluctuates as clients enter and leave the system as specified by the trace. On average there are about 12 active clients. In addition to this foreground load, we introduce permanently backlogged background flows. For the initial set of experiments we fix the bandwidth of the link to twice the average demand bandwidth of the trace. The primary metric we use to measure interference is the average transfer latency of a document i.e., the time between its first packet being sent and the receipt of the ack corresponding to the last packet. We use the total number of bytes transferred by the background flows as the measure of its utilization of spare capacity.
Unless otherwise specified, the values of the and for Nice are set to 0.1 and 0.5 respectively. We compare the performance of Nice to several other strategies for sending background flows. First, we compare with router prioritization that services a background packet only if there are no queued foreground packets. Router prioritization is the ideal strategy for background flow transmission, as background flows never interfere with foreground flows. In addition, we compare to Reno, Vegas( ), Vegas( ).