Did that many years ago for a Mitel client. It took a lot of looking in phone books for area codes (no internet back then) plus we had to change routing via time of day for the least cost.
Is this for least cost or for what caller ID number is being pushed out? If what I think you're doing is correct, you will have to spend a lot of time sorting through the area codes and matching it to the number or numbers you want it to go out on. My advice plan it out all on paper first and then program it one state at a time.


John 807