Hello,
I have a FreePBX PBX (v. 15.0.38) with two HT813 trunks (one for incoming calls and one for outgoing calls). I configured call forwarding for incoming calls, but when a call arrives and is forwarded to the number configured as “Custom Destinations,” even if the call is disconnected, both HT813 devices remain in the “In Use” state, blocking any incoming and/or outgoing calls.
For the incoming HT813, I configured the PSTN disconnect tone as “f1=400@-30,f2=400@-30,c=3000/0;” and for the outgoing HT813, I configured the PSTN disconnect tone as “f1=480@-32,f2=620@-32,c=500/500;”
It has to be the disconnect tone, if you hang up the call, do you still see any active channel if you run asterisk -x ‘core show channels’ ?
Did you try to enable PSTN Disconnect tone detection in the HG813 ?
There are some settings you can test with, like Polarity Reversal, but if i have to bet, it’s the disconnect tone.
Temporarily disconnect the FXO port on an HT and connect a line-powered corded phone in its place. Confirm that you hear a disconnect tone when an incoming or outgoing call is ended by the remote party. To determine the frequencies and cadence, record it (for example with your smartphone) and analyze the file (for example with Audacity).
Or, try to find the data at
Search for Disconnect Tone.
If you can’t get the disconnect tone working properly, you can use a loop current drop or polarity reversal, if provided by the line connected to the HT.
If that is also unavailable, be aware that many FXO devices (but not the HT813) can detect (for example) a minute of silence and disconnect the call. You may also do this in Asterisk, though it’s not a built-in feature.
If you still have trouble, please post: What country is the HT in? What is it connected to (copper pair from central office, cable MTA, fiber ONT, etc.)? Who is the carrier? What have you tried so far?
Thanks @Stewart1 for your reply.
HT is in Italy, with the operator Wind, the telephone cable comes out of the Wind router and arrives at the HT, on the FXO port.
I’ll try to find out how to configure polarity reversal.
Thanks @slobera for your reply. I thought PSTN disconnect tone detection was enabled, but it was actually set to “Off” (by default). My bad!!! I’ve now set it to “On.”
Disconnect supervision isn’t something that you can rely on from analogue interfaces, particularly ones not intended for use with a PABX. If you are lucky, the router will provide it, but really, historically, you would want ISDN or an earth start PABX line, and nowadays, SIP connectivity.
I’m not familiar with the Italian situation, but in some contexts, the line to the provider is SIP, and thre is an FXS ATA in the router, do you up doing VoIP, a short bit of copper, and back to VoIP. Unfortunately, the provider may not allow you to go VoIP all the way, and might not allow you to port the number to someone who will.
If it works, great. Otherwise, listen on an analogue phone to hear whether a disconnect tone is present. If yes, find the frequency / cadence as I described previously. If not, see whether loop current drop or polarity reversal is present.