Analogue Fixed-Line Access


Before 1988, there were many national specifications for analogue access to the telephone network. In 2003, a stable and widely harmonized set of standards became available. The interfaces referred to could be public or private, switched or non-switched, seen from either the network or the terminal side.

They used well-established analogue technologies including:

  • analogue conventional technologies
  • analogue aspects of new technologies, e.g. xDSL
  •  compatibility studies between plain old telephone service (POTS)/public switched telephone service (PSTN) and other technologies, particularly those sharing the same infrastructure

Our Role & Activities

ETSI merged two committees to form technical committee Access, Terminals, Transmission and Multiplexing (ATTM). This committee was responsible for the standards for analogue presented wired interfaces of telecommunications networks.

In the interests of worldwide harmonization, the committee also seeked to promote the basic standards globally, as well as encouraging a consistent approach to standardization of emerging technologies and services.

The fixed network analogue technologies normally did not include radio-specific matters, nor core network and access network issues. However some aspects of terminals and corresponding interfaces using such technologies were to be considered.

POTS/PSTN analogue interface

For access by terminals the former Technical Basis for Regulation TBR 021 content was updated in ETSI Standard ES 203 021.

The attachment requirements for simple voice terminals in TBR 038 are basically still valid. ETSI Standard ES 201 970 provides a harmonized specification of physical and electrical characteristics at a 2-wire analogue presented Network Termination Point (NTP).

Enhanced Features for PSTN over analogue interface

The multi-part ETSI Standard ES 200 778 defines terminal protocols. The multi-part European Standard EN 300 659 specifies subscriber line display services.

The multi-part ETSI Standard ES 201 912 defines the short message service (SMS) communication with the SMS service centre


The following is a list of recently published and frequently downloaded standards. Please use the ETSI standards search to find further related standards in the public domain or to subscribe for alerts on updates of ETSI standards.
For work in progress see the ETSI Work Programme on the Portal.

Standard No.Standard title
ES 203 021 parts 1-3 Harmonized basic attachment requirements for Terminals for connection to analogue interfaces of the Telephone Networks; Update of the technical contents of TBR 021, EN 301 437, TBR 015, TBR 017;
ES 201 970 Public Switched Telephone Network (PSTN); Harmonized specification of physical and electrical characteristics at a 2-wire analogue presented Network Termination Point (NTP)
ES 200 778 parts 1-5 Analogue access to the Public Switched Telephone Network (PSTN); Protocol over the local loop for display and related services; Terminal equipment requirements
EN 300 659 parts 1-3 Analogue access to the Public Switched Telephone Network (PSTN); Subscriber line protocol over the local loop for display (and related) services
ES 201 912 Short Message Service (SMS) for PSTN/ISDN; Short Message Communication between a fixed network Short Message Terminal Equipment and a Short Message Service Centre