[comp.mail.uucp] modems

greid@adobe.com (Glenn Reid) (08/16/89)

I have a NeXT cube running UUCP.  Everything works okay,
but the two computers with which I have connections seem
to have a very high failure rate logging in.  It isn't
broken, because the connection is always made eventually,
but it seems to hang an awful lot.  To be more precise,
their system calls mine, the modem answers and the connection
is established, but there is basically no response from
the "getty" process on my system, the receive and transmit
lights on the modem do nothing, and after about 30 seconds
the calling system hangs up with a FAILED (LOGIN) message
in the log file.

Similarly, trying to log in through tip(1) from the remote
machine often is greeted with null behavior.  I am now
attributing this to a weird modem.  I bought a brand new
(and brand X) Avatex 2400 baud Hayes-compatible modem.  I
haven't had any problems with it when I dial out, but maybe
its auto-answer behavior is not up to spec, especially when
the calling modem has to go through some baud rate
negotiations or something.

Has anyone had any similar experiences, or have any
suggestions?  Should I spend three times what I paid for this
modem and get a real Hayes modem?  Should I spend ten
times it and get a Trailblazer :-?  Is the problem my
modem or "getty" on the NeXT?

Thanks for any insights,

Glenn Reid
Adobe Systems

eht@f.word.cs.cmu.edu (Eric Thayer) (08/16/89)

After spending some time working on uucp here, you might want to make sure
your modem is connected to the Serial A port if you are going to be doing
both dial in and dial out.  The reason being is that Serial A is the only
one which supports carrier detection.  Also, along these lines, you will
want a cable that takes carrier detect from your modem to pin 7 of the
Serial A connector. (Thus, a Mac cable won't do if you want modem control.
For just dial out, a Mac cable would work fine on Serial B).

Aside from these things, we've found that it was possible for getty to think
that the serial port was in use, when in reality nobody was using the port.
I called up NeXT support on this one and they told me that this was
a known bug under 0.9.  One grotesque way of getting around this one was to
craft a script which attempted to see if anyone had dialed out/in and if not,
kill and restart the getty associated with the serial port.  This cleared out
the pending open that getty had and allowed the serial port to function
properly for a while.

Aside from these things, using the -x9 arg and being able to look at some uucp
sources helped me out tremendously.   The sources were very useful in tracking
down modem config problems because I then could figure out what the dialer
was doing.

Hope this helps some harried individuals out there.
-- 
Eric H. Thayer      School of Computer Science, Carnegie Mellon
(412) 268-7679      5000 Forbes Ave, Pittsburgh, PA 15213

jbayer@ispi.UUCP (Jonathan Bayer) (08/16/89)

greid@adobe.com (Glenn Reid) writes:

>attributing this to a weird modem.  I bought a brand new
>(and brand X) Avatex 2400 baud Hayes-compatible modem.  I
>haven't had any problems with it when I dial out, but maybe
>its auto-answer behavior is not up to spec, especially when

Unless you are getting a Trailblazer stick with the Avatex.  The
Avatex is a good modem.  We have them installed at all our customer
sites, and do not have any trouble with them.


JB
-- 
Jonathan Bayer			      Beware: The light at the end of the
Intelligent Software Products, Inc.	      tunnel may be an oncoming dragon
500 Oakwood Ave.				...uunet!ispi!root
Roselle Park, NJ   07204    (201) 245-5922    jbayer@ispi.UUCP