ETSI EN 300 267-4-2000 综合业务数字网(ISDN).7khz电话,可视电话,声像会议和视频会议电信业务.1号数字用户信令系统(DSS1)协议.第4部分:抽象测试套件(ATS)和部分协议额外测试信息实现(PIXIT)形式规范
Integrated Services Digital Network (ISDN); Telephony 7 kHz, Videotelephony, Audiographic Conference and Videoconference Teleservices; Digital Subscriber Signalling System No. One (DSS1) Protocol; Part 4: Abstract Test Suite (ATS) and Partial Protocol Imp