The impact of national ISDN on commercial and tactical communications

The objectives of a national integrated services digital network (NISDN) are shared by both government and industry. Industry has adopted a set of specifications developed by Bellcore, known as NISDN-1 to allow ISDN services and features to operate transparently among switches of different models or manufacturers. ISDN provides multiple services such as voice, data, video, and graphics, on demand, on the existing telephone wiring we use today. With the recent launch of NISDN-1, the local exchange networks collectively have 22 NISDN-1 switches in the United States and Canada equipped with Common Channel Signaling System 7 (CCSS7) and 64 kb/s clear channel capability. Each switch is connected to at least one interexchange carrier network for voice and circuit switched data, and at least one interexchange carrier for packet data. Tactical users must have an information system that is flexible, mobile, secure and often rugged. It must provide timely, accurate information. NISDN is currently addressing these requirements in the commercial market place. As the industry direction of NISDN develops, it should be recognized that the public switched telephone network (PSTN) is evolving from a circuit switched fixed bandwidth toward a packet switched network with flexible bandwidth. As its various network components (including NISDN) transition to an end-to-end digital network, users and service providers will be increasingly able to access, develop, and offer new types of services and applications that will benefit both commercial and government communications