ETSI ETS 300 210-4-1998 综合业务数字网(ISDN).免费电话(FPH)补充业务.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); Freephone (FPH) Supplementary Service; Digital Subscriber Signalling System No. One (DSS1) Protocol; Part 4: Abstract Test Suite (ATS) and Partial Protocol Implementation eXtra Information for Testing (PIXIT) Pr