ETSI EN 300 356-14-2001 综合业务数字网(ISDN).7号信令系统(SS7).国际接口的ISDN用户部分(ISUP)版本4.第14部分:显式呼叫转移(ECT)补充业务(版本4.2.1).ITU-T建议Q.732,第7条(1996)和
Integrated Services Digital Network (ISDN); Signalling System No.7 (SS7); ISDN User Part (ISUP) Version 4 for the International Interface; Part 14: Explicit Call Transfer (ECT) Supplementary Service (V4.2.1; ITU-T Recommendation Q.732, Clause 7 (1996) and