Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Data link layer - Part 1: General aspects [ITU-T Q.920 (1993), modified]; English version ETS 300402-1:1995
Edition 1996-06

European digital cellular telecommunications system (Phase 2) - Data Link (DL) layer - General aspects; English version ETS 300554:1994
Edition 1995-01

Integrated Services Digital Network (ISDN) - Specification of the Remote Frame Handler Interface (RFHI); English version ETS 300458:1995
Edition 1996-04

Integrated Services Digital Network (ISDN); user-network interface data link layer specification; application of CCITT recommendations Q.920/I.440 and Q.921/I.441; english version ETS 300125:1991
Edition 1992-05

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Data link layer - Part 3: Frame relay protocol specification; English version ETS 300402-3:1996
Edition 1997-04

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Data link layer - Part 5: Protocol Implementation Conformance Statement (PICS) proforma specification for the frame relay protocol; English version ETS 300402-5:1996
Edition 1997-04

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Data link layer - Part 2: General protocol specification [ITU-T Q.921 (1993), modified]; English version ETS 300402-2:1995
Edition 1996-06

Integrated Services Digital Network (ISDN) - Autographic conference teleservice - Service description; English version ETS 300675:1996
Edition 1997-11

Integrated Services Digital Network (ISDN) - Videoconference teleservice - Service description; English version ETS 300678:1996
Edition 1997-11

Private Integrated Services Network (PISN) - Inter-exchange signalling protocol, Circuit mode basic services, Data Link Layer (DLL) - Part 2: Abstract Test Suite (ATS) specification; English version ETS 300804-2:1998
Edition 1998-12