scope:

The present document defines the atomic functions relevant for the interface presentations of Synchronous Digital Hierarchy (SDH) leased lines at the Network Termination Point (NTP) and the Terminal Equipment (TE). It specifies the technical requirements for electrical, optical, regenerator and multiplex section layer and SDH path layers. The specification is presented as a delta information of the equipment specification of:

− EN 300 417-2-1 [8] for STM-1 electrical and optical and STM-4 optical section layer;

− EN 300 417-3-1 [9] for STM-1 and STM-4 regenerator section and multiplex section layer;

− EN 300 417-4-1 [10] for SDH path layers (VC-4, VC-3, VC-2 and VC-12);

− EN 300 417-6-1 [11] for synchronization layer functions.

The following physical section layers are used:

− STM-1 electrical interface;

− STM-1 optical intra-office interface;

− STM-1 optical short haul interfaces at 1 300 nm;

− STM-4 optical intra-office interface;

− STM-4 optical short haul interfaces at 1 300 nm.

The interface margins are defined such, that interconnection of different optical interfaces is possible when an appropriate attenuation is inserted.

A connection is presented via interfaces at NTPs. The present document defines the network interface as presented by the leased line provider and should be used in conjunction with the companion standard, EN 301 164 [5], specifying the connection characteristics between NTPs of the leased line. The present document and the connection characteristic standard together describe the technical characteristics of the leased line.

The present document 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.

The present document is to ensure that the interface of the terminal equipment is compatible with the SDH leased line interface. The present document is applicable to all interfaces designed for connection to the SDH leased lines.

Customer premises wiring and installation between terminal equipment and the NTP are outside the scope of the present document.

The conformance test of the section and path layer functions will be addressed under work items EN 300 417-x-3 (x = 2, 3, 4 and 6). Some of the tests described in those ENs are not designed to be applied to the interface of an installed leased line; such tests may be applied to equipment of the kind used to provide the interface. The present document does not include extra details concerning the implementation of tests, nor does it include information of any relevant regulations. The present document does not specify the circumstances in which the tests given in EN 300 417-x-3 (x = 2, 3, 4 and 6) are to be performed.