Access and Terminals (AT) - Special quality voice bandwidth 4-wire analogue leased line (A4S) - Connection characteristics and network interface presentation (Endorsement of the English version EN 300452 V 1.2.1 (2001-07) as German Standard)
接入和终端(AT).特殊质量语音带宽4线模拟租用线路(A4S).连接特性和网络接口表示(认可英语版EN 300452 V 1.2.1(2001-07)为德国标准)