TDM04B card issue


I have TDM04B card with 4FXO modules on my Asterisk. When i get a call from PSTN and the the caller disconnects the call the zap channel stays busy forever and when the called party for example any extension disconnects the call the zap trunk releases the channel.

Please advise. Thanks.

what country are you in and what signalling standard do they use there?
What line mode have you set in /etc/zaptel.conf ?

Many countries use some form of timed break, so kewlstart is a good option to try, like


(I’ve only used the TDM2400, but I believe the 400 uses the same options).

This is a good reference for setting country-specific modes, it’s for the UK but gives info on where country codes can be set. The country code lists can be found in the module source .c file

This is a general reference on detecting disconnect: