This ETS specifies the technical requirements and test principles for connection characteristics of Open Network Provision (ONP) 2 048 kbit/s digital structured leased lines. The leased line operates at 2 048 kbit/s and provides an information transmission capability@ without restriction on binary content@ of 1 984 kbit/s. The remaining 64 kbit/s provides a 8 kHz framing structure in accordance with ETS 300 167 and CCITT Recommendations G.704 and G.706. 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 this ETS. Together with the companion standard@ ETS 300 418 defining the network interface presentation@ this ETS describes the technical characteristics of the leased line service offered to the user. The tests specified in this ETS cannot be carried out by the leased line provider@ while the leased line is in service@ i.e. carrying users' traffic. Thus the tests are designed for bringing into and returning into service@ although there is no obligation to perform these tests each time a leased line is brought into or returned into service. However@ because the connection is structured@ the error performance may be monitored by the leased line provider while the line is in service. This ETS is applicable for leased lines@ including part time leased lines@ for which the establishment or release does not require any protocol exchange or other intervention at the NTP. This ETS specifies the compliance tests for the connection requirements. This ETS does not include details concerning the implementation of the tests@ nor does it include information on any relevant regulations.