I had this same issue with the first Vodavi the company I used to work for put in this same set up on a DMS. We fought and fought with Vodavi and the carrier. THe high voltage reading may have been from the fact the PRI was running across a HDSL T-1 circuit. It is true however, that the carrier would see the D-channel and the B channel trunk groups go down in the switch. I worked in a CO for 2 years, and if a circuit dropped, we would know it. The MCC would light up like a Christmas tree. It is possible if the rep from Cox you were working with was monitoring the wrong span. It doesn't matter if the circuit is passing through 5 different LECs, the switch is always monitoring the span, no matter how many DACS or slicks it passes through.
