scope:

This European Telecommunication Standard (ETS) specifies the characteristics of an access digital section for the Integrated Services Digital Network (ISDN) basic access between the user-network interface (at T reference point, as defined in ETS 300 012 [6] and the local exchange (at V₁ reference point defined in CCITT Recommendation Q.512 [4]) supporting the basic access interface channel structure (defined in CCITT Recommendation I.412 [1] and ETS 300 012 [6]) and the additional functions required for operation and maintenance of the access digital section. This ETS is based on CCITT Recommendation G.960 [7].

The requirements of this ETS and subsequently for the transmission systems based on this ETS, satisfy network performance requirements of CCITT Recommendation G.821 on error performance as well as CCITT Recommendations G.801 and I.350 with regard to availability. Annex A to this ETS is normative and specifies requirements for working with the Exchange Termination (ET) and the definition of the ET layer 1 state machine which are outside the scope of this ETS, but nevertheless are important for the understanding of the behaviour of the access digital section.

Annex B specifies an optional procedure for partial activation and deactivation of the access digital section.

Annex C provides a bibliography of informative references used in this ETS.

A further annex is under development which will specify conformance testing for this ETS. This will be added to this ETS using the ETSI standards maintenance procedures.