I have a good size network of CSE/BCM's and I have some overlaps with a few sites that are coming on board. I would like to change the BCM's so that they can dial a couple of the other sites. If I go into Dialing Plan/DN's and change the DN's that list a DN Type of Set and a Model of ISDN will it cause issues with anything else. What are the DN's with a Model of ISDN used for?