CEPT NET 1 E-1988 连接到电路转换公共数据网张的数据终端设备以及使用CCITT建议X.21接口(T/TE 04-07E)的租赁电路的批准要求
Approval Requirements for Data Terminal Equipment to Connect to Circuit Switched Public Data Networks and Leased Circuits Using CCITT Recommendation X.21 Interface (T/TE 04-07E)