[44098] in North American Network Operators' Group
Re: NY ranks #1 in Internet b/w
daemon@ATHENA.MIT.EDU (Mikael Abrahamsson)
Sun Nov 4 12:48:06 2001
Date: Sun, 4 Nov 2001 18:47:16 +0100 (CET)
From: Mikael Abrahamsson <swmike@swm.pp.se>
To: "nanog@merit.edu" <nanog@merit.edu>
In-Reply-To: <Pine.WNT.4.33.0111041012450.340-100000@neon>
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On Sun, 4 Nov 2001, Alex Rubenstein wrote:
> That sounds somewhat erroneous. Geosynchronus orbit is about 22,500 miles;
> up+down+roundtrip makes that 22,500 * 4, or 90,000 miles;
> 90,000 / 186,000 miles/sec = 483 milliseconds, which, or course, due to
> routers inducing very measureable delay, and the fact that an IP Packet
> takes adds a little delay due to its lenght, is usually a bit more.
Practically, I know back in 1994 when I was in the US and the Nordic
university network had a backup E3 satellite link I had to use, the round
trip times were approx 600ms. 483ms round trip if you're at the equator,
sounds like it can correlate fairly well to 600ms when you have to go
from northern europe, to a satellite hanging up above the atlantic ocean,
and then down to north america (or might even be so satellite over africa,
then to satellite hanging over central america, then down to north
america, ie two satellite hops).
--
Mikael Abrahamsson email: swmike@swm.pp.se
