When I a made a call with a ip phone to the fxo port, i get no call tone, but the "other side" phone rings and can hang up.
During a call, there is only one way voice, the phone on the public voice network "can listen" and the local phone "can talk" but no "listen".
Config on the router:
dial-peer voice 1 pots
description Trucades entrants
incoming called-number .