start-ups used stored program controlled analog switching machines. Data services were almost exclusively facilitated with private line- services over bandwidths ranging between 2.4 and 56 Kbs. In rare situations, 56-Kbs data traffic would be aggregated and carried on T1 backbone facilities. Figure 4-7 shows a high-level topology for the US Public Communications or common carrier network around the time of the break-up and divestiture of AT&T, and the beginning of communications deregulation in the United States. During the course of significantly less than 20 years, the communi- cations landscape changed dramatically. PDH transmission, limited 4 NETWORK TECHNOLOGY AND METHODOLOGY To Hawaii, Guam & Far East To Europe & Middle East International International Gateway Gateway Inter-Exchange Carriers AT&T, MCI, Sprint & Others To Central & Latin America Competitive Access Provider Local Exchange Carriers (RBOCs, GTE, Continental & Others) Private Voice FIGURE 4-7 US Public Communications Network, C. 1984 to approximately 1 Gbs using proprietary techniques, would be re- placed by standardized byte-interleaved, synchronous transmission running at 40 Gbs. Voice traffic was being rapidly overtaken by data traffic. Something called the Internet was 20-plus years out of a Department of Defense initiative, the objective of which was to create a survivable network in the event of catastrophic damage to a single site housing network components passing inter-nodal traffic. By the turn of the 20th century, it seemed like everything using wired transmission was going wireless and everything using wireless was going wired. Standards development that took three to five years was eliminated or brought to reality in drastically reduced time frames driven by special interest groups and new players. Rigid, government- regulated, tariff-based services crumbled in the face of new classes and groups of service providers built around incumbent service providers and their new competitors. Traditional PDH facilities, in particular private 