This European Telecommunication Standard (ETS) defines the physical layer interface to be applied to the SB and TB reference points of the reference configurations of the Broadband Integrated Services Digital Network (B-ISDN) User Network Interface (UNI) at 2048 kbit/s. It addresses separately the physical media and the transmission system used at these interfaces and addresses also the implementation of UNI related Operation Administration and Maintenance (OMA) functions. The physical medium for the interfaces at the SB and TB reference points should take into account that only electrical wires are to be used to cable customer equipment. This ETS mainly is based on ETS 300 300 [13]@ being responsible for the bit rates 155 520 kbit/s and 622 080 kbit/s and the ITU-T Recommendation I.432 [8] being responsible for the bit rates 622 080 kbit/s@ 155 520 kbit/s@ 2048 kbit/s and 1 544 kbit/s.