... \title¹

<>This work was supported in part by NSF ASC-9701333, DoD Modernization Contract 9720733-00, NSF NPACI Award ASC9619020, DARPA Contract N66001-97-C-8531, NSF Graduate Fellowship (UCSD Grant #DGE-9616037), an AT&T Labs Student Grant, and NASA GSRP Fellowship Grant #NGT-2-52251.<>

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... \author²

<>Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA 92093-0114<>

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... \author³

<>Department of Computer Science, University of Tennessee, Knoxville, TN 37996-1301<>

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... media,⁴

Since the time when our initial experiments were run, the vBNS connection to the University of Washington has been activated.

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... media.⁵

At the time of these experiments, CalTech's vBNS connection had been approved.

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... application.⁶

The only difference is that the experimental data server outputs to a socket, whereas the production server runs as a CGI-bin script (and therefore outputs to standard output).

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... times.⁷

Comparison experiments were run back-to-back and multiple times on transfer sizes ranging from 1.5 to 3 megabytes (corresponding to a typical SARA user request). Each comparison run executed for between 15 seconds and 2 minutes with the majority of runs being on the lower end of the range. On average, comparison runs for a single trial enjoyed roughly similar load conditions.

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... re-established.⁸

When this phenomenon was first noticed, we began running traceroutes to each machine to determine if network traffic at any given time was using the vBNS. In one instance, when the NWS reported a sudden increase in bandwidth, traceroute indicated that the vBNS link was being used. Closely monitoring the link, we found that approximately two hours later, the routing changed from vBNS to the general Internet, accompanied by a sudden decrease in bandwidth.

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