North American Network Operators Group

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Re: Satellite latency

  • From: Jim Mercer
  • Date: Wed Feb 27 09:38:40 2002

On Wed, Feb 27, 2002 at 07:25:52AM -0700, David R Huberman wrote:
> My biggest pbeef is the delay while using ssh or telnet. I attribute
> this mostly to speed of light issues. Web browsing, Remedy, and other
> IP software seem to work acceptably fast given my expectations.
> Have you found 'tools' to assist removing delay from the typical
> connection, especially as it relates to ssh?

actually, i think the problem you are seeing is moreso related to the
asymetric nature of the connection (i think you were referring to directway
which is a "one-way" satelite feed).

i generally only use such connections for front-ending a squid server.

the problem is that the round trip routing of your packets gets pretty
diverse.  when you type the packets go out the modem, across a terrestrial
network to the uplink, then back down over satelite.

not much can be done to make that better.

if you "own" the network, there are some tunneling things you can do to make
things appear to be less asymetric, which might help, but if you are an
end-user, you'll just have to tough it out.

alternately, configure your router/etc to use the IP of your dial-up connection
for ssh/telnet, instead of the IP of the downlink.  this will make your
telnet/ssh work using only the dial-up connection, which will eliminate the
asymetric routing.

(ie. interactive traffic uses the dial-up addr, "bulk" services use the

[ Jim Mercer        [email protected]         +1 416 410-5633 ]
[          I want to live forever, or die trying.            ]