X

Let’s start by getting two pieces of trivia out of the way: First, “xDSL” refers to the type of digital modem, not a line per se. Homes and companies already own ordinary copper pair lines. Put a pair of ADSL modems at either end of them, and you’ve got an asymmetrical digital subscriber line. Put SDSL modems on the same line and you’ve got SDSL service instead of ADSL. Same line, different modems. So, “DSL” is a modem, not a line, and a “line” needs two modems for there to be a “service.”