Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!uwm.edu!psuvax1!hsdndev!husc6!ddl
From: ddl@husc6.harvard.edu (Dan Lanciani)
Newsgroups: comp.dcom.modems
Subject: Re: Telebit T2500 hangs as answering modem with V.32/V.42bis connect
Summary: yes
Message-ID: <5082@husc6.harvard.edu>
Date: 16 Dec 90 01:20:25 GMT
References: <3628@orbit.cts.com>
Organization: Harvard University, Cambridge MA
Lines: 31

In article <3628@orbit.cts.com>, pj@pnet51.orb.mn.org (Paul Jacoby) writes:
| 
|   I have been experiencing a problem with a local system I call. The system is
| running a Telebit T2500, and is setup for V.32 connects.  Calling with my
| shiny new Practical Peripherals 9600SA modem (which, incidentally, works
| great when properly configured), I can make a V.32/V.42bis connection with no
| problems.
|   After that, I can generally do my thing for a number of minutes. Then, with
| no real warning, the T2500 will lock up completely. I cannot even drop the
| connection by popping back to command mode and typing ATh.  I must cycle power
| on my end to clear the connections.

	I see a similar problem with two T2500s running in V.32 mode.  (That
should avoid finger-pointing at the-other-modem-maker...)  I find that
a retrain operation (AT&R) will "fix" the situation every time.  The
line-quality register is 100 before, during, and after the problem
appears so I don't think it is really the retrain operation that
fixes it, but rather some side effect.  The whole thing happens at 
least every few hours of use.  There does seem to be a bug in the
T2500's V.32 mode.
	Telebit technical support wasn't very helpful on this.  They
first suggested sending ^Q (I mentioned I had already tried that)
and then said that it sounded too hard to reproduce the problem.  Odd
that they couldn't leave a couple of modems up for a few hours...  I
appreciate the fact that Telebit got stuck with a bad V.32 chip
set in the T2500, and that the T1600 is their hope for the future, but
I also think they might still support the (relatively new) T2500s
out there.  (Unless there is a free upgrade that I missed... :)

				Dan Lanciani
				ddl@harvard.*