Summary

This ITU-T Recommendation is only applicable to international leased circuits that are supported by a data transmission system. The requirements described in this ITU-T Recommendation should ensure that an international leased circuit meets performance limits and is fully tested prior to restoration into service after a fault.

The Maintenance tests described in this ITU-T Recommendation should ideally include periods of normal industrial activity to be representative of typical network conditions. This ITU-T Recommendation has been developed to be consistent with ITU-T Recommendation M.1375 that describes the Maintenance of international data transmission systems.

ITU-T Recommendation M.1380 covers Bringing-Into-Service issues for international leased circuits that are supported by a data transmission system.

This ITU-T Recommendation addresses the Maintenance requirements of leased circuits with a PDH digital presentation at the Customer's premises. Another ITU-T Recommendation is being developed for Bringing-Into-Service and Maintenance procedures for SDH leased circuits.

For leased circuits with an analogue presentation, the Maintenance procedures given in ITU-T Recommendation M.1060 apply, with performance achievement in accordance with ITU-T Recommendations M.1020, M.1025 or M.1040 as appropriate.