Before I shell out for one of these, could the collected wisdom confirm or deny whether this is likely to work? I want to connect a Patton 4554 to one of the outbound ISDN trunk lines on our existing PABX. All the words I've read about the Patton have it functioning as a terminal with an ISDN line coming from the outside world plugged into it; I want to replace one of our existing real ISDN lines with the Patton so that we can call out using a SIP provider instead. Is this possible using the patton or do I need to look at something else? Thanks, Neil.