ADSL（Asymmetrical Digital Subscriber Line）是一种高速数字接入技术，又称为非对称式数字用户线路，是xDSL的一种。xDSL是DSL（Digital Subscriber Line）的统称，意即数字用户线路，是以铜质电话线为传输介质的传输技术的组合，其中“x”代表着不同种类的数字用户线路技术 ADSL (Asymmetrical Digital Subscriber Line) is a high-speed digital access technology, also known as asymmetric digital subscriber line, is a kind of xDSL. xDSL is the collective name for DSL (Digital Subscriber Line), which means digital subscriber line, a combination of transmission technologies using copper telephone lines as the transmission medium, where “x” stands for different kinds of digital subscriber line technologies