ETSI PRETS 300 368-1994 Integrated Services Digital Network (ISDN); Explicit Call Transfer (ECT) Supplementary Service Functional Capabilities and Information Flows
1995ETSI PRETS 300 368-1995 Integrated Services Digital Network (ISDN); Explicit Call Transfer (ECT) Supplementary Service Functional Capabilities and Information Flows
1994ETSI PRETS 300 368-1994 Integrated Services Digital Network (ISDN); Explicit Call Transfer (ECT) Supplementary Service Functional Capabilities and Information Flows