asterisk users - Dec 2004 - ANALOG FXO ZAPTEL & WCFXO & WCTDM module issues seen with intermittent analog lines

Hello, I have found a "bug", I think in the way TDM400P cards handle
FXO
interface disconnect/re-connect problems. Normally I do keep all the wires
connected from my CO / PABX quite securely, but I had a need to re-route the
cable from one side of the desk to another, and I simply disconnected the
RJ-45 connector and plugged it back in. THIS PROMPTLY RESULTED IN VERY VERY
SCRATCHY AUDIO CONNECTIONS WHEN USING THE FXO PORT. Incoming calls were
erratic, outbound calls were almost unuseable, dialled digits were
almost unrecognizable.

Basically after some difficult troubleshooting the fix was:

before disconnecting cable
kill asterisk process
remove WCTDM module
remove WCFXO module
remove ZAPTEL module
and then, reconnect cable,
and then, install ZAPTEL, WCTDM, WCFXO, start asterisk once again.

Apparently during operation of the zaptel driver, disconnect of the cables
to the ports is not recommended. I can replicate this condition easily, and
if other users have any trouble with their analog ports due to the fact that
their connections are flaky after some change (while asterisk is running) I
would love to know how they coped with it.

-samudra



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Hi Samudra,

It is known behaviour for TDM400P card Rev E/F with FXO module. 
Apparently it is a driver issue, which is yet to be fixed (confirmed 
with Digium support).
I had this happening  in about 6-8 hours after normal work, all channels 
would become unusable. No re-wiring of physical lines was needed to 
replicate this situation in my case.

What I am doing to prevent it is described here:

My script to start asterisk is called from inittab, so if the Asterisk 
quits for any reason, it would be restarted promptly.

1) run_asterisk:

#!/bin/bash

/sbin/modprobe zaptel debug=1
/sbin/modprobe wctdm debug=1
/usr/sbin/asterisk -vvvf
/sbin/rmmod wctdm
/sbin/rmmod zaptel
sleep 1
 
2) /etc/inittab entry to run asterisk:

ax:2345:respawn:/usr/sbin/run_asterisk

If you want it to take effect right away (and if your asterisk is stopped):

kill -HUP 1

That will force init process to re-read inittab.

3) Now here is my command restarting Asterisk periodically that would 
remove/reload all the modules, add this line to your crontab:

07 7,11,15,18,22 * * * /usr/sbin/asterisk -rx "stop when convenient"

This way Asterisk will only restart when no calls are in progress. Your 
phone users should not even notice this.

Sincerely,
Andrei

Samudra E. Haque wrote:
>Hello, I have found a "bug", I think in the way TDM400P cards
handle FXO
>interface disconnect/re-connect problems. Normally I do keep all the wires
>connected from my CO / PABX quite securely, but I had a need to re-route the
>cable from one side of the desk to another, and I simply disconnected the
>RJ-45 connector and plugged it back in. THIS PROMPTLY RESULTED IN VERY VERY
>SCRATCHY AUDIO CONNECTIONS WHEN USING THE FXO PORT. Incoming calls were
>erratic, outbound calls were almost unuseable, dialled digits were
>almost unrecognizable.
>
>Basically after some difficult troubleshooting the fix was:
>
>before disconnecting cable
>kill asterisk process
>remove WCTDM module
>remove WCFXO module
>remove ZAPTEL module
>and then, reconnect cable,
>and then, install ZAPTEL, WCTDM, WCFXO, start asterisk once again.
>
>Apparently during operation of the zaptel driver, disconnect of the cables
>to the ports is not recommended. I can replicate this condition easily, and
>if other users have any trouble with their analog ports due to the fact that
>their connections are flaky after some change (while asterisk is running) I
>would love to know how they coped with it.
>
>-samudra
>
>
>
>---
>Outgoing mail is certified Virus Free.
>Checked by AVG anti-virus system (http://www.grisoft.com).
>Version: 6.0.804 / Virus Database: 546 - Release Date: 11/30/2004
>
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> cable from one side of the desk to another, and I simply disconnected the
> RJ-45 connector and plugged it back in. THIS PROMPTLY RESULTED IN VERY VERY
> SCRATCHY AUDIO CONNECTIONS WHEN USING THE FXO PORT. Incoming calls 
I had this kind of problem early on too. At the time I rebooted to fix
it, but I later observed the driver reload would fix it too. The next
step is to imaging that the drivers don't linkstuff being unplugged
and replugged when they are running

Sorta like changing horses in the middle of the stream :)