Synchronous Ethernet is an ITU-T standard that provides mechanisms to transfer frequency over the Ethernet physical layer, which can then be made traceable to an external source such as a network clock.
On this case Ethernet links are part of the synchronization network. The proposal to specify the transport of a reference clock over Ethernet links was brought by operators to ITU-T Study Group 15 in September 2004. The aim of Synchronous Ethernet is to avoid changes to the existing IEEE Ethernet, but to extend to work as a proper synchronous netwerk.
PRODUCTLIJST Sync Ethernet
Multitechnology tester to install and troubleshoot telecom networks