Attachments to the public switched telephone network (PSTN) : category II attachment requirements for 300 bits per second duplex modems standardized for use on the PSTN: NET 21 / European Conference of Postal and Telecommunications Administrations
Attachments to the public switched telephone network (PSTN) : category II attachment requirements for 1200 bits per second duplex modems standardized for use on the PSTN: NET 22 / European Conference of Postal and Telecommunications Administrations
Attachments to the public switched telephone network (PSTN) : category II attachment requirements for 1200 bits per second half duplex and 1200/75 bits per second asymmetrical duplex modems standardized for use on the PSTN: NET 24 / European Conference of Postal and Telecommunications Administrations
Approval requirements for terminal equipment to connect to packet integrated services digital network (ISDN) using ISDN basic access : NET 3 / European Conference of Postal and Telecommunications Administrations