Problems with asterisk and tdm04b cards

I am having problems where asterisk does not answer inbound calls. I have asterisk set up as an automated attendant attached to a Toshiba Strata pbx. I am using two tdm04b cards in a hp proliant dl380 server running slackware v.10. Due to my lack of experience with running linux, I had assistance from a fellow employee who no longer works here.

This issue has been going on for quite some time. I am just finally fed up with having to reboot the system. Stopping and restarting asterisk does not resolve the problem, so the system has to be rebooted. The initial setup was configured by me with the assistance of Digium tech support. Nothing had been changed to the system - I just learned to deal with it. It is to the point where management has been on my back to resolving this problem.

Any assistance would be greatly appreciated.


Just to clarified things, I want to make sure on what you’re talking about.
So you have a 2 TDM400 card with 4 FXO modules on each right ?

You’re problem is that once in a while asterisk stop responding from calls received on the TDM cards. Do I still right ?

If I got correct all you’re problem, here is first solution and reason. It is the zaptel driver for the TDM card that’s causing you trouble. I know I experience it myself :wink:

Now, first, you don’t need to restart the server, you just have to stop asterisk, then unload the driver, reload it, then restart asterisk.

Second, you can probably fix your problem by updating your asterisk version. By the way what version do you currently use ?

If you need more help, ask, I’ll check what I can do.

Good luck !



How do I unload the driver?

If I am reading it correctly, 1.0.1 dated 10/08/2004. I guess I will try to update my asterisk installation to the latest version.

To unload the driver, you this is what I normally do :

stop asterisk (on the CLI: stop now)
rmmod wctdm (or rmmod wcfxs depends on your version of asterisk)
rmmod zaptel

Then reload them :

modprobe zaptel
modprobe wctdm (or modprobe wcfxs)

Start asterisk

Hope this help !

Have you set the Rx/Tx levels on the card. I believe if the Rx levels are too low the card will not answer. You may be right on the edge.

Here is a procedure. For starters I would set RX to 8.0 and TX to 0.0 … x1695.html