 Electric D3 channel bank essentially became the North American standard for digital telecommunications. Indeed that was how most of the day's standards were set, by AT&T fiat. It was not until divestiture that a formal American tele- communications standards body, Committee T1 [19], was established. Come divestiture, the short-haul digital links became the backbone of the RBOC intraLATA networks. A number of new 4ESS digital switches were installed by the RBOCs in major markets to function as access tandems; Nortel's DMS-200 was also a popular digital tandem. Digital switches used T1 ports for their trunks, rather than analog, reducing the need for channel banks and thereby simplifying network operations. AT&T's Long Lines division, renamed AT&T Communications after divestiture, had replaced most of its analog switches with the 4ESS. Most customer owned PBX systems, other than the installed base of AT&T Dimensions, were digital. The last major bastion of analog switching was the end office, and that was gradually changing. One major impetus behind that change was the need to modernize Centrex by adding ISDN. The First Fiber-Optic Boom Optical fiber had been known for many years, but it was not always a very effec- tive conductor of light over long distances. It was useful for specialty applica- tions like desk lamps and flexible point-illumination devices, but it originally had no applications in telecommunications. Corning Glass began work in 1967 on reducing impurities in glass, which led to the development of fiber-optic communications systems. A number of manufacturers became involved in The Great Telecom Meltdown similar developments, working on problems such as the appropriate format of the fiber itself and creating long-life semiconductor lasers to drive the system [20]. In 1977, GTE installed the first such system in practical network use, car- rying 6 Mbps between Long Beach and Artesia, Calif. [21], followed shortly by a Bell System link within Chicago. By the early 1980s, commercial systems were appea