Inside The Box

For years, routing high-quality video over phone lines was the impossible dream: telecom operators could not feed the copper wires that run into offices and homes fast enough. But the dream has finally come true, thanks to a series of technical advances, most notably a piece of networking gear called a Digital Subscriber Line Access Multiplexer (DSLAM, pronounced dee slam). This refrigerator-sized box deftly flips video data from the speedy fiber-optic networks that form the backbone of the phone system to the "final mile" of copper wires. DSLAMs have been around since 1997, but until two years ago they couldn't handle...