dia Bureau. http://www.fcc.gov/Bureau/cable. Sixth Annual Report on Competition in Video Markets, FCC, 99-418, January 2000. Annual Assessment of the Status of Competition in Markets for the Delivery of Video Program- ming, Fourth Annual Report, FCC, 97-423, December 1997. DLECs and ELECs: An Exercise in Oversupply Perhaps the most important real innovation that the telecom industry brought to market during the boom years was DSL service. DSL, broadly construed, is a family of technologies that extend the capabilities of copper local loops to deliver high-speed data service, bypassing the switched telephone network. The introduction of DSL provided the telecom industry with a way to compete with cable modems, without requiring large-scale capital investment to replace the local loop with optical fiber. It also nearly coincided with the passage of the Telecom Act, which led to a highly competitive market. For the sake of clarification, it should be noted that there are several differ- ent DSL technologies, which tend to address different market requirements. Asymetric Digital Subscriber Line (ADSL) is the mass-market offering. It pro- vides downstream (CO-to-subscriber) data speeds of up to 6 Mbps on the best short local loops, with maximum speed declining rapidly with distance; its upstream speed can be as high as 640 Kbps, though much lower rates are more common. ADSL's key feature is that it can share the local loop with an analog phone line. HDSL is the modern substitute for T1 transmission, providing 1.544 Mbps on a 12-kilofoot loop [1]. HDSL is extensively used inside ILEC networks, primarily for T1 service delivery, but it rarely sold as a DSL service per se. Symmetric DSL (SDSL) provides two-way capabilities at maximum speeds that again vary with the loop length, typically a bit over 2 Mbps on short loops but falling to the 300-Kbps range on very long loops. VDSL potentially delivers up to 50 Mbps over short distances, such as a "fiber-to-the-curb" or neighborhood-node scenario. ISDN DSL (IDSL) delivers ab