scope:

The present document specifies the physical and electrical parameters of interfaces based on ITU-T Recommendations G.702 [1], G.703 [2] and G.707 [3] for interconnection of digital network elements: - in-station (i.e. for distances below a few hundred metres); - using metallic (symmetrical or coaxial) pairs; - at 64, 2 048, 8 448, 34 368 and 139 264 kbit/s hierarchical levels of the Plesiochronous Digital Hierarchy (PDH) and at the first level of the Synchronous Digital Hierarchy (SDH) (STM-1 at 155 520 kbit/s). The present document also describes the requirements for the physical and electrical parameters of the 2 048 kHz synchronization interface.