It is mainly used for the audio connection between the main distribution frame and the switching bureau user, and can also be used for the audio connection between other communication devices. Can support voice applications, digital telephone, fax, program-controlled switch, data equipment connection, telecommunications integrated wiring branch lines and trunk lines, etc. Tiancheng local telephone cable can transmit audio analog signals below 150 KHZ and digital signals of 2048 Kbit/s and below. In certain cases, digital signals of more than 2,048 Kbit/s can also be transmitted. It can also be used to combine building trunk cabling and 110 wiring frame and other wiring equipment to achieve voice transmission and wiring.