I have a 2 - 2 port FXO modules. On one of these I have two lines from PSTN. Both ports are configured the same (as far as I can tell), port 1/0/1 works fine, but port 1/0/0, when a call is received continues to ring even though the user (Cisco phone) has answered. The caller continues to hear ringback, but the user can faintly hear the caller talk. I have switched the connection from the PSTN and the problem stays on that port. So I know it is not the line cord, jack, or problem with the business line from the PSTN.
Any idea? Please let me know.