ETSI PRETS 300 359-4-1997 综合业务数字网(ISDN).忙时用户呼叫接通(CCBS)补充业务.数字用户1号信令系统(DSS1)协议.第4部分:用户的抽象测试套件和部分协议额外测试信息实现
Integrated Services Digital Network (ISDN); Completion of Calls to Busy Subscriber (CCBS) Supplementary Service; Digital Subscriber Signalling System No. One (DSS1) Protocol; Part 4: Abstract Test Suite (ATS) and Partial Protocol Implementation eXtra Info