david@cgh.UUCP (David Kozinn) (12/08/89)
I recently attached a Telebit Trailblazer Plus modem to my Microport
System V/386 for use with UUCP and the like. Things are working well,
except for one very annoying problem. It seems that while I can send at the
expected high speeds, when a file of any size larger than perhaps about 2 K
is sent to my system, the transfer rate drops from the 1700-1800cps range
down to something like 325cps. Watching the modem, it seems that my system
is holding up things, and since this happens with several systems I'm
pretty confident that the problem is on my end, not on the remote end.
(I've further determined that when I hook up my DOS system directly to the
Unix system and try file xfers at the same 19.2K speed, I run into similar
problems.)
A friend has suggested that there may be some buffers which have filled up
and need to be emptied before the transfer may resume, and that certainly
seems likely, but since I know that I've been able to send to systems that
aren't as speedy as mine (this is a Compaq 386/16, I've sent to 286
machines and they've been able to receive at 19.2Kb just fine), there must
be some way to tune things. Given that Microport isn't exactly providing
customer support, and I haven't (as yet) been able to find anything in the
manuals, I was hoping that someone out there in netland could help me.
Please reply via email to one of the addresses below, I'm on a guest system
right now because my local news feed is currently down (though I'm still
getting mail.) I'll summarize to the net.
David Kozinn | UUCP: {rutgers | uunet}!cbmvax!cgh!monymys!david
MONY Financial Services | UUCP: ...!rutgers!princeton!mccc!monymsys!david
Glenpointe Center West | Internet: cgh!monymsys!david@manta.pha.pa.us
Mail Drop 75-14 | GEnie: D.KOZINN
Teaneck, NJ 07666-6888 | Telephone: +1-201-907-6990johnk@opel.uu.net (John Kennedy) (12/11/89)
Could also be overruns of the TB incoming data at your system's uarts. This would cause your system to ask the distant end to resend much data. Since you're on a 386, I would highly recommend Jim Murray's asy driver and replacing your uarts with 16550's. I'm able to receive 1200-1400 bytes/sec from a TB on a Microport 286. I have ordering information on the 16550s from Arrow Electronics; email if you're interested. John -- John Kennedy johnk@opel.uu.uunet Second Source, Inc. Annapolis, MD