I have two loop start pots lines.
Until asterisk decides to hang up…the lines remain tied up for over a minute (sometimes longer).
Its really apparent when an incoming call is sent to IVR or voice mail.
A call that is answered by a “live” person will hang up if the person on the asterisk side hangs up first but not if the caller hangs up first. (asterisk waits for over a minute or until the user on the asterisk side hangs up. this was done as a test. We don’t normally stay on the line after a customer hangs up.