[47250] in North American Network Operators' Group
Download estimate tool?
daemon@ATHENA.MIT.EDU (Brennan_Murphy@NAI.com)
Wed May 1 15:54:14 2002
Message-ID: <B481990C9658D411BD3C009027D6F544040C5523@SNC-5-87.nai.com>
From: Brennan_Murphy@NAI.com
To: nanog@merit.edu
Date: Wed, 1 May 2002 14:53:38 -0500
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I'm looking for a tool to estimate file download times given a certain
set of variables: file size, available bandwidth, latency, receive window
and
circuit utilization. To explain:
Suppose I have a single OC3 serving FTP downloads to individuals all over
the globe. If the OC3 is not heavily utilized *and* I know the bandwidth
and latency between my FTP server and a client's workstation, I can
make a rough estimate of how long it will take for a file of a particular
size to download. I could create a matrix in Excel based on latencies and
bandwidths (factoring in TCP receive window sizes) and that would give
me a quick reference tool for gauging how long something should take
to download given a fair number of scenarios.
But what if I want to enhance such a matrix to factor in what happens
to download times in those various scenarios as the utilization of
that OC3 approaches 100%? I could make alot of edits to above
mentioned Excel matrix....but that would get tricky and visually
unappealing.
Can anyone recommend a tool that makes it easy to play with the
above variables...a sort of modeling tool not quite so fancy
or expensive as Opnet for example? Maybe a webpage with a
Java applet ? Or maybe a fancy Excel file?
Thanks,
BM
