[clue-tech] Downside of increasing TCP window size?

[Nate Duehr]

Jim Ockers wrote:

> The Layer 2 is a 4800 baud MSAT satellite dialup to the PSTN and our
> own terminal server (with an analog modem) using Linux pppd on both
> ends.  The TCP connection is an SSL request to an apache web server, 
> using the Perl Net::SSL libraries via LWP::UserAgent and possibly 
> HTTP::Request.

Is it possible to dump the MSAT/PPP mess with all those layers and 
switch to something designed for fixed satellite data.  (And I don't 
mean nasty ol' Starband.)

Just going by your description, it sounds like this is a fixed satellite 
service, and doing the whole MSAT/dial-up/PPP thing sounds like it's 
adding all sorts of lovely things.  Is PPP already optimized for the 
path's MTU size, for example?

Sounds ugly.

Now you're going to ask: What do I recommend they switch to?  That's 
hard... see, I know there ARE lowerish-latency satellite links out 
there, 'cause a friend of mine used to do some work at McMurdo Station 
in Antartica and well, it's hard to tell he's not on a terrestrial link 
-- we did some VoIP stuff between here and there and got some special 
allowances to do some link tests, etc... ICMP is normally blocked at the 
terrestrial side of the link at a firewall, but we had a couple of IP's 
to experiment with for a few days.

But I'm sure they're using something quite expensive for that "last 
mile" (last 23,000 miles?  heh) that's probably managed by DoD, or 
similar.  I don't have any details... but maybe it's commercial.

Any chance MSAT's really expensive and worth shopping a little with 
PanAmSat and InmarSat for possible better data solutions a bit?  Lots of 
C-band and Ku-band bandwidth flying "up there", depending on the part of 
the world you're trying to reach.  I'm not sure what MSAT is, but why 
does it need chatty whiny PPP riding over it to make it work?

Nate