voice troubleshooting case debrief-connection plar opx

connection plar: on fxo port router goes off hook when ring voltage
detected and places the call to the number configured. If the calling party
hangs up, you can end up with the called phone continually ringing.
- connection plar opx: router places call to configured number when ring
detected but does not go off-hook. Once the called party answers, the fxo
port goes off-hook. If ringing stops (ie calling party hangs up) prior to
the called party answering, call is dropped. Hence no infinite ringing
phone as described above.

When you have the "opx" statement removed, the calling party will hear telco ringback stop immediately when our FXO port seizes the line, but called party hasn't answered yet. In effect, two stage dialing. This may annoy some callers when the called party never answers but billing has begun because the telco thinks the called party has answered. "OPX" fixes this problem, but of course you have some other problem to debug in your situation ...