Correct. The remote ring signal (90VAC @ 20Hz IIRC) that causes their phone's bell to ring is generated by their central office. However, I believe (it's been a

Correct. The remote ring signal (90VAC @ 20Hz IIRC) that causes their phone's bell to ring is generated by their central office. However, I believe (it's been a long time since I did anything phone related) that the "ringback" that the caller hears is only generated when the remote switch verifies that it can complete the call, so it's probably synchronized that way.