Bandwidth for High Speed Networks

05 ms and the length of each 4 tcp rlm1 rlm2 rlm3 35

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Unformatted text preview: re at all times. FRED and CSFQ also are able to achieve a high degree of fairness. Our next experiment simulates Web tra c. There are 60 TCP transfers whose inter-arrival times are exponentially distributed with the mean of 0.05 ms, and the length of each 4 TCP RLM1 RLM2 RLM3 3.5 Throughput (Mbps) 3 2.5 2 1.5 1 0.5 0 0 50 100 150 200 250 Time (sec) a DRR 4 TCP RLM1 RLM2 RLM3 3.5 300 450 TCP RLM1 RLM2 RLM3 3.5 3 2.5 2.5 Throughput (Mbps) Throughput (Mbps) 400 4 3 2 1.5 2 1.5 1 1 0.5 0.5 0 0 0 50 100 150 200 250 Time (sec) 300 350 400 450 0 b CSFQ 4 50 100 150 200 250 Time (sec) 300 350 2.5 Throughput (Mbps) 3 2.5 450 TCP RLM1 RLM2 RLM3 3.5 3 400 c FRED 4 TCP RLM1 RLM2 RLM3 3.5 Throughput (Mbps) 350 2 1.5 2 1.5 1 1 0.5 0.5 0 0 0 50 100 150 200 250 Time (sec) 300 350 400 450 d RED 0 50 100 150 200 250 Time (sec) 300 350 400 450 e FIFO Figure 7: The throughput of three RLM ows and one TCP ow along a 4 Mbps link . transfer is drawn from a Pareto distribution with a mean of 20 packets 1 packet = 1 KB and a shaping parameter of 1.06. These values are consistent with those presented in the 5 . In addition, there is a single 10 Mbps UDP ow. Table 2 presents the mean transfer time and the corresponding standard deviations. Here, CSFQ performs worse than FRED, mainly because it has a larger average queue size, but still almost one order of magnitude better than FIFO and RED. 3.5 Large Latency All of our experiments so far have had small link delays 1 ms. In this experiment we again consider a single 10 Mbps congested link, but now with a propagation delay of 100 ms. The load is comprised of one UDP ow that sends at the link speed and 19 TCP ows. Due to the large propagation delay, in this experiment we set the bu er size to be 256 KB, and K , K , and Kc to be 400 ms. Table 3 shows the average number of packets of a TCP ow during a 100 seconds interval. Both CSFQ and FRED perform reasonably well. 3.6 Packet Relabeling Recall that when the dropping probability of a packet is non-zero we relabel it with the fair rate so that the label of the pa...
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This document was uploaded on 03/04/2014 for the course ENG 531 at Rice.

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