ISDN: from custom to commodity service

With a toehold in specialized applications, ISDN is poised for takeoff as the all-digital telephony service affordable by everyone. ISDN has been on the worldwide telecommunications agenda for the last decade and is one of the most important junctions of the Information Superhighway. Despite early satire of the network as the Interface Subscribers Don´t Need, operators have diligently brought it to market as an outstanding telephony service capable of revolutionizing users´ lives. The ISDN options added by vendors to their product lines are costly because of low installed volume. And high tariffs deter many users who could get ISDN services in their area, however much they appreciate all its technical goodies. Still, from a technological point of view, ISDN is well prepared for mass-market deployment in commodity applications. It needs only a further push by operators (lower tariffs, better geographical coverage) to become in reality the Interface all Subscribers Definitely Need