I always wondered if there really was a Three Stooges Telecom. Whomever put this in was way beyond and idiot. It would have taken 3 idiots to figure this BS out. Now your into Custom Engineering, in which you lose in a MAC situation unless you have done it before or your lucky.
This is when you tell them to call the Genius who set it up or install the proper hardware. Unless you have the time to waste and see it as a challenge. Still the customer would be better served with proper gear.