ation, across two pairs of copper wire; repeaters were needed every 6,000 feet. The D-series channel banks at each end mapped voice into fixed channels using time division multiplexing (TDM). To this day, the de facto standard for carrying telephone lines across T1 is based on the way the D3 and D4 channel banks did so. The actual T1 transmission system has, however, been supplanted by newer technologies such as high-bit-rate digital subscriber line (HDSL), which carry DS-1; T1 remains a nickname. ITU-T Recommendation G.711 describes 64 Kbps pulse code modulation schemes for voice digitization. (ITU-T stands for International Telecommunications Union Telecom- munications Standardization Sector.) The encoding used in the United States, Canada, and a few other countries is different from the one used in Europe and most other countries. There were three Dimension variants. Dimension 100, with a nominal 100-line capacity, and Dimension 400, with a nominal 400-line capacity, were essentially two packages of the same basic design. Dimension 2000, with a somewhat more powerful processor, was built out of multiple interconnected switching nodes. Because these VTPP rates were, on the whole, usually higher than the two-tier rates that they replaced, VTPP was sometimes said to mean "virtually twice the present price." No connection to the later Z-TEL, a competitive local exchange carrier. The original Ztel's name was an acronym of its four founders' names, Zannini, Tao, Epstein, and Lento. The Great Telecom Meltdown [10] 77 FCC 2d 384 (1980). [11] See, for instance, Cannon, R., "The Legacy of the Federal Communications Commission's Computer Inquiries," Federal Communications Law Journal, Vol. 55, No. 2, March 2003, http://www.law.indiana.edu/fclj/pubs/v55/no2/cannon.pdf. In re Amendment of Sections 64.702 of the Commission's Rules and Regulations (Third Com- puter Inquiry) and Policy and Rules Concerning Rates for Competitive Common Carrier Serv- ices and Facilities Authorizations Thereof Communications Protocols under Sect