Modem Configuration

[Rushank]

D-Class 10.20 Configured serial port for Dial-in with security features.

The problem is modem does not answer the second call once I hang up after a dial in. (TR light on modem is not getting ON )
Also I get junk character on password screen

Any clue..?

[Sanjay_6]

Hi Rushank,

I think the session is not getting killed on disconnect from the modem and that could be the source of your problem. The getty process does not get restarted. Try this link for a few suggestions,

http://us-support3.external.hp.com/cki/bin/doc.pl/sid=afb8afd80ecbc3830d/screen=ckiDisplayDocument?docId=200000006446006

Hope this helps.

Regds

[Sanjay_6]

Hi Rushank,

This link walks you through the modem configuration on a D-class system,

http://us-support3.external.hp.com/cki/bin/doc.pl/sid=8b55b4b81740903218/screen=ckiDisplayDocument?docId=200000058669370

Hope this helps.

Regds

[Rushank]

Sanjay,

I've read this before but my problem still persists..

[Sanjay_6]

Hi Rushank,

Make sure that only one getty process is running for the port and that it is using the device file for modem. what is the gettydefs (from /etrc/gettydefs) entry that you are using for this port.

Hope this helps.

Regds

[Rushank]

Hi,

This is my /etc/gettydefs file
19200N # B19200 HUPCL IGNPAR ICRNL IXON OPOST ONLCR CS8 CREAD
ISIG ICANON ECHO ECHOK IXANY TAB3
# B19200 SANE CS8 IXANY TAB3 HUPCL
#login: #300


Here is /etc/inittab

a0:3:respawn:/usr/sbin/getty -t 300 -h ttyd1p0 19200N

I've similar setup on my other server where dial-in modem works absolutely fine.

Strange thing the Terminl Ready light is not getting ON and I've only one getty running

[Sanjay_6]

Hi Rushank,

Modify this entry in gettydefs like this,

19200N # B19200 HUPCL IGNPAR ICRNL IXON OPOST ONLCR CS8 CREAD ISIG ICANON ECHO ECHOK IXANY TAB3 # B19200 SANE CS8 IXANY TAB3 HUPCL #login: #19200N

Note the modification is 19200N in place of 300 at the end of the line. Also make sure your modem speed is set to 19200. What is your current modem speed. Does it work first time before hangup. Also if you kill the getty process or any other process running on the port connected to modem, does the TR light comes on and the login prompt displayed during dialup.

Hope this helps.

Regds

[Rushank]

Hi,

Modem and port are set on speed 19200. Modem never gets TR light ON ,but It connects first time successfully and gives me login prompt and then If I want to try again It just rings.
And If I disconnect and reconnect the modem cable at the server end and reset the power of modem I get connection again.

Secondly I get login prompt correctly but junk charater appears in place of password. This could be a modem issue. I checked with other modem and that works fine.

I want to solve the getty problem first then I'll look in to modem settings.

[Sanjay_6]

Hi Rushank,

Try this entry,

19200N # B19200 SANE CLOCAL CS8 ISTRIP IXANY TAB3 HUPCL # B19200 SANE CLOCAL CS8 ISTRIP IXANY TAB3 HUPCL #login: #19200N

Do a "init q" to make the change effective.

Hope this helps.

Regds

[Rushank]

Hello Sanjy,

TR light on Modem doesn't come up. If I hangup and try second time Server modem doesn't pick up the line.

BTW I no more get junk on password prompt but my TR problem remains

[Sanjay_6]

Hi Rushank,

Is the getty process restarted on the port after you connect and disconnect for the first time. If you kill the getty process and allow another getty process to start, does it work, does the TR light comes on. Do a ps -ef when you are connected at the first time, disconnect and again do a ps -ef and see if the getty restarts. check the TR light. Kill the process (getty or any other process) for that port now and see if the TR light comes on.

Hope this helps.

regds

[A. Clay Stephenson]

This is a classic symptom of a modem nof configured to flag the CD line. You either need to set a dip switch on the modem, configure the modem to flag CD, or make sure that the CD line is not hard-wired to a pin that is always on.

You are close now but a breakout box will help you very quickly diagnose the problem.

[Rushank]

The TR lights is not coming ON at all , even after I kill the getty process. If I remove modem cable and put it back and then if I try I get connection but TR light not even blinks. I don't think it's responding on killing getty process, Matter of fact there is only getty running on the server and I just found getty for console is also not running!. Only getty is running is for the modem port.
I want to see TR light ON

[Rushank]

Clay,

If I replace a different modem the result is same, The TR never comes up. But the same modem works very well on other server.

[Rushank]

This modem problem still persists ant other clue..? What is CD flag..?

Modem does not pickup if you hangup and try to reconnect. Just rings..

[A. Clay Stephenson]

CD is Carrier Detect. Here is what I think is happening: The host never see's a loss of Carrier Detect and thus never spawns a new getty. This can happen when a) the modem assets CD at all times b) the cable is hard-wired so that CD is asserted all the time, or c) you are using a device node that ignores modem control. A breakout box is very useful to display the status of the CD line.

[Rushank]

But this Modem works perfectly on other server.
What is breakout box..?

[A. Clay Stephenson]

Does it work perfectly on the same server with the same cable? You could very easily have an incorrectly wired cable. That is what a breakout box will help you determine. If is a small box with DB25 connectors on each side. It has a number of LED's which can be used to monitor typically a minimum of 8 lines. It simply becomes a cable extension. Typically is has a row of DIP switches that you can close to make a stright-thru connection or open and then patch from one pin to another. It's sort of a baby patch-panel.

---------------------------------------

If the cable is the same and the other server is the same class box with the same tty ports then you need to compare the major/minor device numbers of the working version with those of your bad version. Man 7 termio to get a very good description of the various minor device numbers and how how they effect modem control. I would also look at inittab and gettydefs.

[Rushank]

This is my gettydefs
19200U # B19200 SANE CLOCAL ISTRIP IXANY TAB3 HUPCL
# B19200 SANE CLOCAL CS8 ISTRIP IXANY TAB3 HUPCL
#login: #19200U

This is inittab
a0:3:respawn:/usr/sbin/getty -h ttyd1p0 19200U

[A. Clay Stephenson]

Do an ls -l /dev/ttyd1p0. While I think I know what this device node is, the NAME could be anything, it's those major and minor device numbers that your box cares about. Also, is the machine that this modem works on the same ann using the same cable?

[Rushank]

ls -l /dev/ttyd1p0

crw--w--w- 1 root dialin 1 0x010006 Mar 7 17:26 /dev/ttyd1p0