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<TITLE>New benchmark test results for High-Speed TCP, Scalable, FAST, BIC, H-TCP.</TITLE>
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<P><FONT SIZE=2>Results of some recent experimental work to evaluate the performance of these TCP proposals are now available online at www.hamilton.ie/net/eval/. <BR>
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To our knowledge, this is the first comparison that controls for differences in network stack implementation - the Linux network stack has known performance issues in high-speed environments (e.g. see www.hamilon.ie/net/) and so most patches for new congestion control algorithms also implement many changes unrelated to the congestion control algorithm making comparison of congestion control algorithm performance difficult, if not impossible, when patches are used directly.<BR>
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In summary, we find that both Scalable-TCP and FAST-TCP consistently exhibit substantial unfairness, even when competing<BR>
flows share identical network path characteristics. Scalable-TCP, HS-TCP, FAST-TCP and BIC-TCP all exhibit much greater RTT<BR>
unfairness than does standard TCP, to the extent that long RTT flows may be completely starved of bandwidth. Scalable-TCP, HS-TCP and BIC-TCP all exhibit slow convergence and sustained unfairness following changes in network conditions such as the start-up of a new flow. FAST-TCP exhibits complex convergence behaviour.<BR>
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Our measured data is available in an online archive, as well as summary reports. Comments appreciated.<BR>
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Doug<BR>
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