filePro Printing over a Satellite

[Bill Vermillion]

On Wed, Mar 10, 2004 at 06:27:06PM -0500, Jay R. Ashworth thus spoke:
> 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.

WOOPS -  EFN - not ELFN - but they are called 'elephants.

See rfcs 1185, 1323, and 2488.  1185 refrences high speeds, 1323
also references high speeds, 2488 is data over satellite.

> 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.

And I was getting a full-feed on a trail-blazer and feeding 24
sites - with one phone line.  We had a 3-way backup in Orlando.

One main site got data from converent and GE, another got
convergent, and I got GE.  so we were redundant

My Radio Shack 6000 with it's 70MB internal drive that I put in -
would regularly be in the top 500 usenet sites for news going
through - as I was feeding so many.  We had about 70 machine
in our oau.org domain.

Not only was there less news - it was of higher quality.

And we were able to route our email through UCF.

Bill

-- 
Bill Vermillion - bv @ wjv . com