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Synchronous Digital Hierarchy - the standard for transmitting digital information over optical networks such as SONET.
Synchronous Digital Hierarchy. Before SDH, networks were extremely rigid and creating a new link between two points was time consuming.
Posted by waqasahmad
For details :
en.wikipedia.org/wiki/Synchronous_optical_networking
Posted by sagitraz
SDH or synchronous digital hierarchy standard developed by the International Telecommunication Union (ITU), documented in standard G.707 and its extension G.708
Posted by tom
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