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) - 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 6: Test Suite Structure and Test Purposes (TSS&TP) specification for the general protocol; English version ETS 300402-6:1997
Edition 1997-11

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Signalling network layer for circuit-mode basic call control - Part 4: Test Suite Structure and Test Purposes (TSS&TP) specification for the user; English version ETS 300403-4:1997
Edition 1997-11

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol; signalling network layer for circuit-mode basic call control - Part 5: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user; English version ETS 300403-5:1997
Edition 1998-08

Broadband Integrated Services Digital Network (B-ISDN) - B-ISDN Operation and Maintenance (OAM) principles and functions; English version ETS 300404:1997
Edition 1998-07

Network Aspects (NA) - Metropolitan Area Network (MAN) - Interconnection of MAN Switching Systems (MSS) based on an Asynchronous Transfer Mode (ATM) interface; English version ETS 300405:1995
Edition 1995-11

Corrigendum to DIN ETS 300405:1995-11 (ETS 300405:1995/Corrigendum:1995)
Edition 1996-05

Methods for Testing and Specification (MTS) - Protocol and profile conformance testing specifications - Standardization methodology; English version ETS 300406:1995
Edition 1996-01