NEC a Japanese based technology company in the last forty years is known through acquistions of TIE in Connecticut and their neighbors in the Far East, Nitusko which in the 1980s and 1990s had many American interconnects for Key Telephone Systems. While NEC was knwon for it's reliabilty.. wait there was some crap hardware at one point, another American company NEC bought and remade it for their own existing systems to handle being connected to PC based servers and do IP Telephony. That comapny was called Sphere Communications, and some of their documentation prior to acqusition is on this directory. You see NEC's acquisition and their migration to it becoming Univerge. Ironically NEC has sunsetted their telephony business thanks to cheaper and inferior technologies that lacks reliability and functionality other than standard landlines because the IT guy is stubborn to learn some olkd ideas to apply to modern contextes.