Analog PSTN channel remain active after call disconnection

I found this common issue on all version of asterisk that calls on analog (FXO) PSTN lines remain active in asterisk server while the caller has already terminated the call. It takes some more time to disconnect the call. This cause to keep busy the pstn lines for a while and the concurrent call capacity is highly effected.

Please suggest possible settings for DAHDI or any other suggestion to solve this.

For outgoing calls, this is how analogue PSTN lines normally work, when calling other land lines.

For incoming calls, how does your PSTN operator signal disconnects? The only options Asterisk has are a brief removal of battery voltage from the line, and busy tone applied to the line.

well outgoing is fine and this problem is only in incoming.
Is there a way to find the PSTN operator signal disconnects ?
PSTN operators are providing standard phone lines and I don’t expect that they will do some customization or settings particular for the asterisk PBX.

You need to speak to you operator and as for CPC signal to be applied to the line, this isnt normal on a domestic pstn line but if you explain that you connecting the line to a BX then they should enable it as ALL pbx’s expect to have some kind of clearing signal.

Can you please brief more about CPC signalling or can refer some links or materials so that I can look into it before I ask operator.

I had this problem and i solved with this

;Uncomment these lines if you have problems with the disconection of your analog lines on the chan_dahdi.conf


But you have to check with your telco because in other location i still have the problem and it is a PSTN Line issue

That’s a second best option, and depends on the network operator putting busy tone on the line.