Synchronous Digital Hierarchy (SDH) is a standard for transport of digital signals with different capacities. In SDH technology management, functionality for service provisioning, fault management and restoration is built into the transport network.
SDH equipment and networks are currently undergoing a major evolution to 'data over SDH' or 'next-generation SDH' to transport data services more effectively. This encompasses both new SDH technologies, such as Virtual Concatenation and GFP/LAPS encapsulation, as well as significant changes to network equipment architectures.
