On one phone it is ringing once and that is it. When it happened earlier today to me, I know that my forwarding is off, and there shouldn't be a coverage path for my extension (if I understand it). When someone dials my extension, it does not ring anywhere else. I have since talked to the person that called me. She called, let the phone ring 3 times, and hung up when I didn't answer. Except I did. When I answered I got a dial tone. The caller ID showed it was her, and she dialed my number (so the voicemail shouldn't be involved, if my understanding is correct). Based on other instances of this, I believe that it would not have rang more than just the one time.
