SUMMARY: modem problem

From: scott@ncifcrf.gov
Date: Fri Sep 04 1992 - 22:13:14 CDT


Hello,

Here is the original message:

 I am trying to install a dialin/dialout modem on a sparc2 running a 4.1.1
GENERIC kernal. The modem will dial out fine but it will not work when dialing
in. I have followed the instructions in the systems administrator's manual in
chapter 11 'Adding Hardware to Your System' but it will still not work. I have
even called sun but the could not offer any help.

I am trying to install a DSI 9624LE+ on serial port B. This modem is 9600 baud
with pseudo 19200 capability.

I dial in to the system with kermit and get connected but after the
CONNECT EC notice nothing happens. On a healthy system after you hit carriage
return a few times the login prompt would appear. However, I don't see
anything.

I have tried to run getty at 14400, 9600 and 2400 and all three fail the
same way. I have got the system to log me in one time in about 100 tries.
I don't know if it was luck but it was not reproducible.

After the CONNECT EC message it will usually wait for about 30 seconds or so
and then I will get the NO CARRIER message and get booted off.

I have even tried to run trace -p on the getty and this didn't seem to
lend any useful information. Getty appears to waiting at a read. Sometimes
getty appears to be responding to the carriage returns but even this is
unpredictable and sporadic.

the following is the pertinent lines from the /etc/ttytab file.

#
# @(#)ttytab 1.6 89/12/18 SMI
#
# name getty type status comments
#
console "/usr/etc/getty std.9600" sun on local secure
ttya "/usr/etc/getty D2400" dialup off remote
ttyb "/usr/etc/getty D9600" dialup on remote
cua1 "/usr/etc/getty D2400" unknown off

The following are the lines for the files in /dev.
crw--w--w- 1 root 12, 1 Aug 25 11:23 /dev/ttyb
crw------- 1 uucp 12, 128 Jul 1 15:27 /dev/cua0

A getty does indeed run on ttyb
fcsparc2# ps ax | grep getty
18049 ? S 0:00 - D9600 ttyb (getty)
18051 p6 S 0:00 grep getty

The following is the session where I tried to dial in from an AIX machine.
% ./wermit
C-Kermit 5A(179) BETA, 8 Feb 92, IBM RS/6000 (AIX 3.x)
Type ? or HELP for help
C-Kermit>set line /dev/tty0
C-Kermit>set modem hayes
C-Kermit>set speed 9600
/dev/tty0, 9600 bps
C-Kermit>connect
Connecting to /dev/tty0, speed 9600.
The escape character is ^\ (ASCII 28).
Type the escape character followed by C to get back,
or followed by ? to see other options.
at
OK
atdt6560
CONNECT EC
x # sometimes I get spurious x's and ~
NO CARRIER

END of Original message:

Thanks to all those who responded.

"Adam W. Feigin" <feigin@iis.ethz.ch>
mau@beatles.CSELT.STET.IT
overdijk@ECN.NL (Harrie Overdijk)
 tgsmith@spdev.East.Sun.COM (Timothy G. Smith - Special Projects)
mdl@cypress.com (J. Matt Landrum)
Kevin Cosgrove 642-2676 <qiclab!solomon!kevinc>
kalli!upstage!glenn@fourx.Aus.Sun.COM (Glenn Satchell)
pan@beo.ix.de (Peter S. Berk)
"Gordon C. Galligher" <gorpong@sbcoc.com>
matt@wbst845e.xerox.com (Matt Goheen)
briant@falcon.teleride.on.ca (Brian Taylor)
mrt!mike@suntan.West.Sun.COM (Mike Flynn)
Dwight Ernest <dwight@hyphen.com>

What solved the problem for me was the following:

1. use kermit (or any program that can communicate with the modem) to
    interact with the modem. In kermit do a 'set speed 38400' and then connect
    to the modem. After connecting to the modem the modem will sync with
    kermit at 38400 after you do your first 'at' command.

2. Turn on hardware flow control by using the 'at*F3' command to the modem.
 
3. You can then exit from kermit and the modem will be left at 38400.
    This is the speed you want the modem to use when talking to the sun
    because in step five you will be running getty at 38400.

4. Set the eeprom setting from your serial port to enable hardware
    flow control. See the eeprom man page for details.

5. run getty at a fixed speed with a std.xxxxx entry in the gettytab
    instead of an autobauding type (D38400) of entry. I chose 38400.

note. turn off the getty running on the serial port when trying to connect
to the modem with kermit and then turn back on when finished.

---------------
        E-mail: scott@ncifcrf.gov ,Phone #: (301) 846-5798
        Title: Sr. Systems Manager/Analyst



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:49 CDT