Hey Bill,
I agree that mis-optioning will not block a signal, but the signal will not be clean in any way, shape or form. The end devices will always give plenty of indication that something is amiss.
Coding does not usually come into play for cross-connects on high-speed cards (In a Titan 5500 for example, CST to CST cross-connects require you to specify only framing).
LECs are not always passive. Run a circuit through a Fuji or a DDM-1000 and you add devices that must have some sort of coding specified.
The surest way I can think of to prove the CPE is to swap the suspect circuit and a known working circuit, and see how the problem moves.
If the problem follows the card, replace it. If the problem follows the circuit, have the LEC fix their problem.
Paul
