An international communications standards developed within ANSI, ISO, and CCITT for sending voice, video, and data over digital telephone lines. ISDN requires special metal wires and supports data transfer rates of 64 Kbps(64,000 bits per second). Most ISDN lines offered by telephone companies supply two lines at once, called B channels . One line may be used for voice and the other for data , or both lines can be used for data to obtain data rates of 128 Kbps.

【通讯】整体服务数位网路。缩写为 ISDN。一个国际通讯标准由 ANSI、ISO、及 CCITT 所制定，在数位电话线路上用以传输音响、电传视讯、数据传输等功能。ISDN 需使用特殊的线路，传输率达到 64 Kbps.