filePro Printing over a Satellite

[Jay R. Ashworth]

On Wed, Mar 10, 2004 at 03:45:28PM -0500, Bill Vermillion wrote:
> Considering that there is usually a limit to the number out
> outstanding unacked packets and the minimum round-trip time 
> on a satellite link with both up and down coming from the bird
> is over 6/10th of a second you can see that you could get delays.
> 
> The 10-40 second delay sound like buffering at some location, or
> stopping the upflow.
> 
> Satellite links up and down have a minimum of 100,000 miles round
> trip time.  25 up 25 down for send and then same for receive.
> 
> These come under the desicription of 'elephants' - ELFN - Extremly
> Long Fat Networks - that is normally associated with long [eg
> cross-country] fibre links that can hit 10Gb/sec.  Keeping the pipe
> filled and then getting acks back in time was partially solved by
> using huge packet sizes.

Indeed.  When you have a weird pipe like a satellite, you have to tune
your TCP windows and related parameters carefully for reasonable
thruput.

> At that time you could get a comlete usenet feed at 9600.  Current
> complete feeds would over fill a T3 [ eg over 50Mbps ] on a 24x7
> basis.  

<oneupsmanship>
Back in 1984, at SPJC, I used to be able to *read* the entire Usenet
feed.  With my eyes.  I remember the day I gave up.
</oneupsmanship>

We got it at 1200bps then, from usfvax2.

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
Member of the Technical Staff     Baylink                             RFC 2100
The Suncoast Freenet         The Things I Think
Tampa Bay, Florida        http://baylink.pitas.com             +1 727 647 1274

        "They had engineers in my day, too."  -- Perry Vance Nelson