A 48 56 64 kbit s data circuit termination equipment standardized for use on digital point - to - point leased circuits 点对点数字租用电路上使用的48 56 64kbit s数据电路终接设备技术要求
3.
Interface between data terminal equipment and data circuit termination equipment employing serial binary data interchange 使用串行二进制数据交换的数据终端设备和数据电路终接设备之间的接口