Delay in Internal Extension Hanging Up After External Call Ends


I am slowly building up my Asterisk box for home use. It is pretty basic and uses a Digium analog card with an FXS card connected to the PSTN and two FXO modules for internal extensions. Here is the incoming call handler from extensions.conf:

exten => s,1,Answer
exten => s,2,Set(CallerIDString=${CALLERID(all)})
exten => s,3,Dial(DAHDI/1&DAHDI/2,20,rt)

No voicemail for the moment as I am continuing to use an analog cordless with built in answering machine as one of the extensions.

What I am observing is that when the PSTN hangs up as the answering machine answers, the internal extension remains connected for several seconds after the the external line has hung up. Is there any way to force the extension to hang up when the external call hangs-up?



Just a small correction FXO is used to connect the PSTN line, FXS modules are the one to use analog phones as extensions. And related to the Hangup issues , Asterisk need time to detect the hangup by busy tone.Ob the Asterisk side you can Uncomment these lines on your /etc/asterisk/chan_dahdi.conf


Also you can do a quick search on the forum with the keyword disconnect supervision and you will fine a lot information related to your issue

Basically, if you want reliable disconnect supervision, you need to use ISDN or VoIP. The fact that the line is clearing after a few seconds suggests you may already have busy detect.

I’m still trying to get a handle on the terminology! What I understood from setting up the chan_dahdi.conf file was on the PTSN side is that it is a FXS card (as it is a station to the PTSN line) using FXO signalling and the extensions connected to FXO cards (FXS signalling) as the Asterisk box looks like the central office to the extensions. I went as far as to put the colors of the cards in the comments!! I will review!

Speaking of terminology, thanks for the keyword suggestions! I find half my battle is figuring out my search terms. For this little activity I seemed to keep going down the path of “hang-up.” The trials and tribulations of being a newbie!

Your suggestions and patience are appreciated!



Based on your comments and ambiorixg12, looks like I need to do some research on busy detect.



You appear to have FXO and FXS mixed up. FXO cards internconnect with foreign exchange offices, i.e. they are on the PSTN side. They use FXS signalling, because asterisk is then acting as a station (i.e. as a phone).