YD/T 992-2006.Technical Requirements and Testing Methods of Telephone Additional Functions. 1范围 YD/T...
YD通讯标准
YD通讯标准
YD通讯标准
YD/T 992-1998 电话机附加功能的基本技术要求及检验方法
YD/T 992-1998.Technical requirments and test methods of telephone additional functions. 1范围 YD/T 992...