ETSI EN 300 141-6-1998 综合业务数字网(ISDN).呼叫保持(HOLD)补充业务.1号数字用户信令系统(DSS1)协议.第6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); Call Hold (HOLD) Supplementary Service; Digital Subscriber Signalling System No. One (DSS1) Protocol; Part 6: Abstract Test Suite (ATS) and Partial Protocol Implementation eXtra Information for Testing (PIXIT)