Broadband Integrated Services Digital Network

In the 1980s the telecommunications industry expected that digital services would follow much the same pattern as voice services did on the public switched telephone network, and conceived an end-to-end circuit switched services, known as Broadband Integrated Services Digital Network (B-ISDN).

Before B-ISDN, the original ISDN attempted to substitute the analog telephone system with a digital system which was appropriate for both voice and non-voice traffic. Obtaining worldwide agreement on the basic rate interface standard was expected to lead to a large user demand for ISDN equipment, hence leading to mass production and inexpensive ISDN chips. However, the standardization process took years while computer network technology moved rapidly. Once the ISDN standard was finally agreed upon and products were available, it was already obsolete. For home use the largest demand for new services was video and voice transfer, but the ISDN basic rate lacks the necessary channel capacity.