GB/T 9541-1988
Active2400 bits per second duplex modem using the echo cancellation technique standardized for use on the general switched telephone network and on point-to-point 2 wire leased telephone-type-circuits
在普通电话交换网和点对点二线租用电话型电路上使用标准化的回波抵消技术的2400比特/ 秒双工调制解调器