Access and terminals (AT) - Analogue access to the Public Switched Telephone Network (PSTN); Subscriber line protocol over the local loop for display (and related) services - Part 3: Data link message and parameter codings (Endorsement of the English version EN 300659-3 V 1.3.1 (2001-01) as German Standard)
接入和终端(AT)-公共交换电话网(PSTN)的模拟接入;显示(及相关)业务本地环路上的用户线路协议.第3部分:数据链路报文和参数编码