YD/T 1686-2007.Speech Quality and Transmission Performance Requirements and Testing Methods for IP T...
YD通讯标准
YD通讯标准
YD通讯标准
YD/T 1686-2011 IP 电话终端设备语音质量及传输性能技术要求和测试方法
YD/T 1686-2011.Speech quality and transmission performance requirements and testing methods for IP t...