uucp throughput on international link using Multi-Tech V.32
F.F. Jacot Guillarmod
ccfj at quagga.uucp
Fri Nov 2 07:32:25 AEST 1990
I am getting about 500 cps transfer rate on a long distance (South Africa
to U.S.) uucp dialup link. Locally, I am using a Multi-Tech V.32 modem,
and the site in the U.S is using a Telebit T2500. My dialler program
is a version hacked from the Hayes2400 dialler.
The local system is a 386 clone running SCO Xenix 2.3.2, and the uucico
(which supports only 'g' protocol) has been modified to use a window
size of 7 - this change increased throughput from about 220 cps to the
present levels. And, yes, I am driving my serial line to the modem at
19.2 kb!
Questions:
a) is 500 cps over such a link expected, or is better throughput
possible?
b) if better performance is possible, how can it be attained? My news
feed is batched/compressed, and I am using smail 3.1 to compress and
batch normal mail as well.
c) if this performance is about what can be expected, can anybody give
an explanation of why faster transfer just doesn't happen? Our
local PTT is willing to assist, but I need to know what to ask
them.
d) does anybody have a 'genuwine' Multi-Tech V.32 dialler program they
are willing to share? Particularly one that uses parameter tailored
for talking to Telebits...
e) if you could start from scratch, what modems would you use to
maximize the speed of such a link? Would V.42 make any difference,
given that the files to be transferred are already compressed?
The reasoning behind this question is that an improvement in the
performance translates into hard cash, and could write off the
cost of new hardware in a few months.
Thanks in advance for any enlightenment on these points.
--
F.F. Jacot Guillarmod - Computing Centre - Rhodes University - Grahamstown
Internet: ccfj.quagga at f4.n494.z5.fidonet.org uucp: ..!m2xenix!quagga!ccfj
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