I have a POTS line that is supposed to ring on a telephone set. Doesn't that have to be programmed as a PVR/PVN key? when i call the POTS line it rings to one of my atty's rollover DN (I called it three times and all three times it went there). this is for a remote site. how do i track down what DN this POTS line is on without actually being there? PS: this website is the greatest thing to happen to my career since the invention of the no-desi-required M3900 sets!