The present document specifies the technical requirements and test principles for connection characteristics of ONP 2 048 kbit/s digital unstructured leased lines. A connection is presented via interfaces at Network Termination Points (NTP) 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. Together with the companion standard, EN 300 418 [3] defining the interface presentation, the present document describes the service offered.