"Breaking The Digital Barrier: ISDN History"

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An examination of Integrated Services Digital Networks (ISDN) history includes taking a step back into a look at the original analog telecommunication services, better known to the industry as Plain Old Telephone System (POTS). A massive interconnection of wires comprised the early phone network that connected telecommunications customers across the world.

Purely mechanical in nature, these copper wires served as the beginnings of the telecommunications industry, but it did have its limitations. The wires had issues of breakdown, and static interference "line noise" was quite common. Long distance telephone services had to be routed through operators and multiple switchboards, making long distance communication difficult, and often time-consuming.

As early as the 1960s, the telecommunications industry began converting its internal analog systems to those of digital switching, based on transmitting "packets" of digitized data. Almost every internal telecommunication services system today has converted to this digital switching technology. But the POTS lines still dominate the industry from the internal switches to the telecommunications customers.

Digitizing Networks - ISDN History

The Internal Telephone and Telegraph Consultative Committee (CCITT) began a movement that included recommendations and guidelines for digitizing the telecommunication services networks to the customer. Initiated in 1984, the telecommunications industry was proactive in praise for the ISDN system, but slow to act in implementation.

Two of the major networks at the time, Northern Telecomm and AT&T, chose to implement digital networking that fit within the parameters of the recommendations, but involved proprietary equipment that created incompatibilities in the varying telecommunication services.

It was not until the early 1990s that the telecommunications industry finally came to an agreement on how to proceed in a singular forward motion of digital telecommunications technology, and set a standard to be used by all. The rest is ISDN history.