The Cisco 6100 system is part of the Cisco DSL product family that provides end-to-end service by carrying data between a subscriber's home or office, a telephone central office (CO), and various networks. The Cisco 6100 system sends and receives subscriber data (often Internet service) over existing copper telephone lines, concentrating all traffic onto a single high-speed trunk for transport to the Internet or a corporate intranet. Asymmetric digital subscriber line (ADSL) and symmetrical digital subscriber line (SDSL) customer premises equipment (CPE) devices, which are connected to PCs or routers at the subscriber site, modulate data so that the data can travel over telephone lines to the Cisco 6100 Series digital subscriber line access multiplexer (DSLAM) at the CO.