本标准介绍了出现在网络和双绞线线路远端的高速数字用户线第二代（HDSL2）信号的电气特性。信号的传输介质为单双绞线对或双绞线对（HDSL4），支持负载为1.544 Mbps的全双工传输。本接口标准提供了网络和远程安装之间令人满意的传输的最低要求。设备可以通过附加功能和程序来实现。

This standard presents the electrical characteristics of the High bit rate Digital Subscriber Line - Second Generation (HDSL2) signals appearing at the network and remote ends of the twisted-wire pair line. The transport medium for the signals is, a single twisted-wire pair or two twisted-wire pairs (HDSL4) that supports full-duplex transmission with a payload of 1.544 Mbps. This interface standard provides the minimal set of requirements for satisfactory transmission between the network and the remote installation. Equipment may be implemented with additional functions and procedures.