9600 Dialup line on SPARCstation 1

[K. Dorian Flowers]

Hi, I've been trying to install a Practical Modem 9600SA
(Hayes-compatible) as a dialup line on one of the serial ports of a
SPARCstation 1.  (We have the SunOS 4.1.1 installed right now).  I've
followed the manual instructions, creating the proper device files with
the minor device numbers, editing the /etc/ttytab file and sending a
HUP signal to the init process.

I get the following problem, however. I can call out on the modem just
fine, at all baud rates. When I try to call into the modem from another
system, the carrier is lost almost _immediately_ after a carrier is
detected. Even when the switch settings on the modem are set to ignore
the DTR signal from the SPARCstation, this behavior occurs.

There are a few exceptions to this behavior. I can log on at 300 baud,
or once at any baud rate if the workstation has been booted since my
last attempt to log on.

Does anybody have any idea of what kind of problem I might be having?
Should I give more information?

Kim Flowers
kimf at tybalt.caltech.edu