scope:

The present document specifies the technical requirements and test principles for the connection characteristics and the physical and electrical characteristics (except safety, overvoltage and EMC aspects) of the network interface presentation of special quality, voice bandwidth, 4-wire, analogue leased lines, provided as part of the minimum set under the Council Directive on the application of Open Network Provision (ONP) to leased lines (92/94/EEC) (see annex E). A connection is presented via interfaces at Network Termination Points (NTPs) and includes any equipment that may provide the NTP. Signals between terminal equipments are subject to impairments during their transfer over the connection. The limits to these impairments are stated in the present document although in practice the overall performance may be considerably better.