[45871] in North American Network Operators' Group
Re: Satellite latency
daemon@ATHENA.MIT.EDU (Jeff Mcadams)
Tue Feb 26 21:10:40 2002
Date: Tue, 26 Feb 2002 21:08:27 -0500
From: Jeff Mcadams <jeffm@iglou.com>
To: Tim Devries <zsolutions@cogeco.ca>
Cc: nanog@merit.edu
Message-ID: <20020226210826.A9328@iglou.com>
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In-Reply-To: <014d01c1bf3b$44bfca00$ea9a8d18@evilinc>; from zsolutions@cogeco.ca on Tue, Feb 26, 2002 at 09:03:01PM -0600
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Also sprach Tim Devries
>I think this question may have been asked before, but what is the
>minimum latency and delay I can expect from a satellite connection?
>What kind of delay have others seen in a working situation? What
>factors should be considered in end to end connectivity architecture
>when utilizing a satellite link?
Well, as a lower bound, geosynchrous orbit is between 22,000 and 23,000
miles and the speed of light is approximately 186,000 miles per second.
The math is not terribly complex from there.
Figure up and back is around 45,000 miles, then if you're doing a
round-trip, you're up to around 90,000 miles...that's on the order of a
half second right there.
That's why I laugh when BellSouth tries to tell the Kentucky PSC that
satellite is a competitor to DSL...ever tried to type over a 1/2 second
lag on telnet or ssh? Painful doesn't adequately describe it.
--
Jeff McAdams Email: jeffm@iglou.com
Head Network Administrator Voice: (502) 966-3848
IgLou Internet Services (800) 436-4456
