Hi!
We have a problem with a fresh new installed Asterisk 14.0.3.6, related to ALL LINE BUSY message when someone try to make a call.
This don’t happen always, but almost, expecially when someone try to make a call very quickly after a call is terminated. Is like the call remain ‘active’ for a sort of time.
If you are using Asterisk 14 then be aware it is not supported for bug fixes and hasn’t been touched in that regard for quite awhile.
As for your problem without a console log showing an attempt and it failing noone can really answer. You also haven’t stated what technology is in use - SIP or PRI/Analog? If it’s SIP do you have a SIP trace showing the problem?