Data communication - Use of the X.25 packet level protocol in local and metropolitan area networks; identical with ISO/IEC 8881:1989 (status of 1991)
Edition 1996-01

Integrated Services Digital Network (ISDN) - Attachment requirements for terminal equipment to connect to an ISDN using ISDN basic access - Layer 3 aspects; English version ETS 300104:1991/A1:1994
Edition 1994-11

Integrated Services Digital Network (ISDN); support of CCITT recommendation X.21, X.21bis and X.20bis based Data Terminal Equipments (DTEs) by an ISDN; synchronous and asynchronous terminal adaption functions; english version ETS 300103:1990
Edition 1992-02

Private Telecommunication Network (PTN); signalling protocol at the S-reference point; circuit mode basic services; English version ETS 300192:1992
Edition 1993-09

Open Systems Interconnection - Protocol for providing the connectionless-mode network service - Part 3: Provision of the underlying service by an X.25 subnetwork; identical with ISO/IEC 8473-3:1995
Edition 1996-06

Private Telecommunication Network (PTN) - Signalling protocol at the S-reference point - Circuit mode basic services; English version ETS 300192/A1:1996
Edition 1996-08

Terminal Equipment (TE) - Test procedures for teletex; English version ETS 300017:1994
Edition 1995-02

Integrated Services Digital Network (ISDN); user-network interface layer 3; specification for basic call control; english version ETS 300102-1:1990
Edition 1992-02