Satellite latency

Jim Mercer jim at reptiles.org
Wed Feb 27 14:51:15 UTC 2002


On Wed, Feb 27, 2002 at 07:45:07AM -0700, David R Huberman wrote:
> Actually, it's a two-way connection,

hmmm, ok, my bad.  if it is two-way, then the telnet/ssh buffering shouldn't
be that bad. at least in my opinion.  i use ssh over (two-way) satelite
connections all the time, and usually don't have much trouble unless the link
is full.

> and I sent you a private e-mail, but hey, in front of 10k folks is cool.... :>

i figured my response might be informative to others in a similar (albeit
mis-interpreted) situation.

> 
> > 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
> > downlink).
> >
> > --
> > [ Jim Mercer        jim at reptiles.org         +1 416 410-5633 ]
> > [          I want to live forever, or die trying.            ]
> >

-- 
[ Jim Mercer        jim at reptiles.org         +1 416 410-5633 ]
[          I want to live forever, or die trying.            ]



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