This is a weird request that I got from an engineer I work with. Basically we have an in-house device that connects over a T-1 line to an SX-2000 via an NSU. When I try to send an ARS code and the additional digits this phone call is immediately terminated. If I use direct trunk access I can access the trunk, so I don't believe there are any restrictions from this working. Basically we want to be able to call from one trunk using ARS out on an outside CO trunk.