Integrated Services Digital Network (ISDN) - Direct Dialling In (DDI) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 1: Protocol specification
Edition 1998-09-01

Integrated Services Digital Network (ISDN) - Direct Dialling In (DDI) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 2: Protocol Implementation Conformance Statement (PICS) proforma specification (incl. Diskette!!!)
Edition 1998-10-01

Integrated Services Digital Network (ISDN) - Direct Dialling In (DDI) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 3: Test Suite Structure and Test Purposes (TSS&TP) specification for the user
Edition 1998-09-01

Integrated Services Digital Network (ISDN) - Direct Dialling In (DDI) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user (incl. Diskette!!!)
Edition 1998-10-01

Integrated Services Digital Network (ISDN) - Direct Dialling In (DDI) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 5: Test Suite Structure and Test Purposes (TSS&TP) specification for the network
Edition 1998-09-01

Integrated Services Digital Network (ISDN) - Direct Dialling In (DDI) 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) proforma specification for the network (incl. Diskette!!!)
Edition 2000-01-01

Integrated Services Digital Network (ISDN); Direct Dialling In (DDI) supplementary service; service description; english version ETS 300062:1991
Edition 1992-09

Integrated Services Digital Network (ISDN); Direct Dialling In (DDI) supplementary service; functional capabilities and information flows; english version ETS 300063:1991
Edition 1992-09

Integrated Services Digital Network (ISDN); Direct Dialling In (DDI) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 1: Protocol specification (Endorsement of the English version EN 300064-1 V 1.3.4 (1998-06) as German standard)
Edition 1999-12

Broadband Integrated Services Digital Network (B-ISDN) - Digital Subscriber Signalling System No. two (DSS2) protocol; Direct Dialling In (DDI) supplementary service - Part 1: Protocol specification [ITU-T-Recommendation Q.2951, clause 1 (1995), modified] (Endorsement of the English version ETS 300661-1:1997 as German Standard)
Edition 2000-05