56kb modem success

[brian (Brian Kantor)]

Last weekend I finally got a pair of DSY 56kb modems interfaced to my
computers and I'm quite happy with the result; I'm getting about
3kbyte/sec FTP transfers between a pair of 8mhz XT-clones.

I used an Eagle card for the interface on one end of the link, and an
Ottawa PI card on the other end.  The PI card is nice, because it's DMA
and the computer doesn't completely die during an incoming packet like
it does with the non-DMA Eagle card.

Bdale reports transfer rates of 6.5kbyte/sec or better with faster
machines or by eliminating disk i/o, so I suspect I'm running as fast
as I can with the slow disk systems I have.  MTU and MSS were both
around 1k for this test; larger might be a bit better.

Next step is to ruggedize the modems, boost the power, and interface
something that will work dependably as a packet switch on a 5,000 ft
mountain in lightning storms and power fails.  Once we have that, we
can start building a real inter-city network.  Yah!
        - Brian