From Ethernet to Synchronous Ethernet

This article presents a comprehensive overview on the upcoming migration from the current Ethernet infrastructure towards synchronous Ethernet. It first presents within a synchronization perspective a brief description of the current Ethernet and compares it to the SDH/SONET technology. The intent is to outline the current Ethernet gaps in terms of network synchronization. Secondly, it describes the key additional functional blocks, as specified by the ITU-T (study group 15, question 13), enabling Ethernet to support frequency synchronization (or syntonization) and thus yielding to the standardized synchronous Ethernet. Finally, it points out some possible migration scenarios by putting the stress on both technical difficulties and operational investments foreseen during the implementation phase.