"This TBR specifies the attachment requirements and corresponding test principles for a terminal equipment interface for connection to the Network Termination Points (NTPs) of ONP 2 048 kbit/s digital structured leased lines (D2048S) using 120 ? interfaces with an information rate of 1 984 kbit/s without restriction on binary content. A terminal equipment interface that conforms to this TBR will also conform with TBR 012 for connection to an ONP 2 048 kbit/s unstructured leased line. The term ""attachment requirements"" in the context of this TBR describes the essential requirements for access which have to be fulfilled under the Second Phase Directive (91/263/EEC). Conformance to these requirements does not guarantee end-to-end interoperability. This TBR is applicable to all interfaces designed for connection to the ONP 2 048 kbit/s structured leased line. It covers the essential requirements for the physical and electrical characteristics of the terminal equipment interface. Customer premises wiring and installation between the terminal equipment and the NTP are outside the scope of this TBR."