From: gam@sun_jimh.mentorg.com (Gary Merrick)
Subject: Hayes modem on a Sun: HELP!
Date: Sat, 17 Oct 1992 01:20:31 GMT
Organization: mentor

I have a pair of Hayes Optima Smartmodems that I want to install with dial-in/dial-out
capabilities on a Sun3 with SunOS 4.1.1. This should be no big deal, right? Wrong.

I have read the Sun Sys Admin manual repeatedly, as well as all related Usenet articles
over the past several months. Technical support from both Sun and Hayes was of absolutely
no help. I'd REALLY appreciate it if somebody out there could give me some advice.

Here's the situation:
I am attempting to test my modem configuration by dialing out on one port and into the
other, all on the same computer (it's easier to change configurations on one system rather
than two, and it shouldn't matter whether I use one computer or two separate ones).

With gettys turned off both modem serial ports, I can successfully dial out (using tip)
from one modem and connect to the other, and can echo characters across the connection.
But as soon as I spawn a getty on the answering port, I can no longer establish the
connection; the answering modem picks up the connection and immediately drops it -- no
connection tones, or any of the standard sounds associated with normal modem connecting.

Things I've tried:
As a test, I tried directly connecting the two ports together with an RS232 cable
(no modems), and can successfully tip into one port and get a login prompt from the
answering one; ie., the connection works without the modems. Another test I did was to
call the answering modem using an analog telephone, and I was able to get the connection
tones.

(As a side note, as soon as I spawn a getty on either of the modem ports, the modem SD
and RD lights flicker as though data is being exchanged. This continues until I stop the
getty. The Hayes manual says that this indicates a problem with flow control.)

I initially tried using a hardware carrier by appropriately configuring my /etc/remote
file (for tip) and /etc/gettytab file (for login), ttysoftcar -n, and used "at" commands
to make the modem compatible. I believe the cables have all 25 pins asserted.
This configuration does not work.

Somebody on Usenet said that Suns don't work well with the hardware carrier, so I tried
XON/XOFF instead by changing the parameters in the same places I did for the hardware
carrier (/etc/remote, /etc/gettytab, ttysoftcar -y, & modem "at" commands).
This configuration doesn't work either. Somebody else on Usenet said that modems don't
like a configuration like the one I'm using for testing (originating and answering on
the same system), so I tried splitting up the modems between two computers. No dice.
I also tried disabling the return of result codes, as well as numerous variations of
modem configurations. None of these worked.

All tests were run in standard asynchronous mode (no error control,etc.). It would be
wonderful if I could get it working at 38.4K (v.42bis), but at this point I would be
satisfied with anything. Can somebody please tell me what I'm doing wrong? It really
shouldn't be this difficult...

 ____________________________________________________________
| Gary Merrick                System/Network Admin from Hell |
| gam@sje.mentorg.com    alt email: gary_merrick@mentorg.com |
|____________________________________________________________|


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