|
|
|
|
|
|
|
|
|
|
|
|
| home | help | back | first | fref | pref | prev | next | nref | lref | last | post |
Date: Sun, 4 Nov 2001 10:19:52 -0500 (Eastern Standard Time) From: Alex Rubenstein <alex@nac.net> To: Iljitsch van Beijnum <iljitsch@muada.com> Cc: Rafi Sadowsky <rafi-nanog@meron.openu.ac.il>, "nanog@merit.edu" <nanog@merit.edu> In-Reply-To: <20011104150829.N75854-100000@sequoia.muada.com> Message-ID: <Pine.WNT.4.33.0111041012450.340-100000@neon> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Errors-To: owner-nanog-outgoing@merit.edu > 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, alex@nac.net, latency, Al Reuben -- -- Net Access Corporation, 800-NET-ME-36, http://www.nac.net --
|
|
|
|
|
|
|
|
|
|
|
|
| home | help | back | first | fref | pref | prev | next | nref | lref | last | post |