Integrated Services Digital Network ( ISDN ): Narrowband and Broadband Services and Applications
John Thompson · The Internet Encyclopedia · 2004
Abstract Integrated Services Digital Network (ISDN) began development as a set of international standards in the 1960s, well before the conversion of the analog public switched telephone network to digital technology. Its promises were uniform, high‐function services to end users, common interfaces for network components that assured interoperability for service providers, and standards for products that would simplify markets for equipment vendors. This vision was never fully realized for ISDN because of slow and incomplete deployment. Nevertheless, ISDN, ISDN standards, and the standards development process have had a significant impact on telecommunications well beyond the magnitude of its deployment. This chapter explores both the narrowband definition of ISDN that is deployed today in telephone administrations around the world and the broadband definitions that have appeared in the form of Asynchronous Transfer Mode (ATM) products and services. It also discusses the other key services and technologies derived from ISDN that have helped shape telecommunication networks today and for the future.