North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: NY ranks #1 in Internet b/w

  • From: Alex Rubenstein
  • Date: Sun Nov 04 10:21:48 2001

> Over 300 ms for less than 10000 km (6000 miles) is not great. Even a good
> satellite should be able to provide better round trip times...

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.

When working on this stuff (specifically on a hop from Oslo to Jerusalem),
I recall 630 ms being the average latency.

But, to make my point, Geosync orbit could never, ever be less than 483
milliseconds, ever.

-- Alex Rubenstein, AR97, K2AHR, [email protected], latency, Al Reuben --
--    Net Access Corporation, 800-NET-ME-36,   --