Essential requirements for terminal equipment intended for connection to digital leased circuits of the public telecommunications network using a ccitt recommendation x . 21bis interface 使用ccitt推荐标准x . 21bis规定的接口与公共通信网络数字租借线路终端设备相连接的基本要求
2.
Essential requirements for terminal equipment intended for connection to unstructured digital leased circuits of the public telecommunications network using a ccitt recommendation g . 703 interface at a rate of 2048 kbit s with a 75 unbalanced presentation 使用ccitt g . 703推荐标准规定的接口在75欧姆不对称表示的2048 k比特每秒扫描率与公共通信网非结构数字出租电路终端设备相连接的基本要求
3.
Essential requirements for terminal equipment intended for connection to unstructured digital leased circuits of the public telecommunications network using a ccitt recommendation g . 703 interface at a rate of 34368 kbit s with a 75 unbalanced presentation 使用ccitt g . 703推荐标准规定的接口在75欧姆不对称表示的34368 k比特秒扫描率与公共通信网非结构数字出租电路终端设备相连接的基本要求
