I remove the analog phone, and plug in a panasonic wireless phone. The phone has an LED which will blink when there is an incoming call. Now, when I call the google voice number, the panasonic phone's LED is indeed blinking. So, it seems like the call is actually coming to the OBI110-attached panasonic phone, but the phone is just not ringing at all.
What do I need to change in the OBi110 setting to make the phone ring when there is an incoming call?