ETSI PRETS 300 369-2-1995 综合业务数字网(ISDN).显式呼叫转移(ECT)补充业务.数字用户1号信令系统(DSS1)协议.第2部分:协议实现一致性声明(PICS)形式规范
Integrated Services Digital Network (ISDN); Explicit Call Transfer (ECT) Supplementary Service; Digital Subscriber Signalling System No. One (DSS1) Protocol; Part 2: Protocol Implementation Conformance Statement (PICS) Proforma Specification