The Synchronous Ethernet (SyncE) MIB is defined for monitoring network synchronization based on ITU-T G.781 clock selection.
Synchronous Ethernet (SyncE) is a standard defined for delivering timing to the remote NEs through a Packet Network. SyncE is well defined by ITU-T which included G.8261, G.8262, G.8264 and G.781. It leverages the PHY layer of Ethernet to transmit frequency to the remote sites. Its functionality and accuracy mimics that of the SONET/SDH network because of its physical layer characteristic. In order to allow best clock source traceabiliy, correctly define the timing source and helps preventing timing loop, Synchronization Status Message is required for SyncE. This is similar to SONET/SDH. However, since SONET/SDH use 4 bits from the two S bytes in the SONET/SDH overhead frame for such message, Ethernet relies on a different channel called ESMC (Ethernet Synchronization Messaging Channel) which is based on IEEE 802.3 Organization Specific Slow Protocol.
Glossary: AIS: Alarm Indication Signal ATM: Asynchronous Transfer Mode EEC: Ethernet Equipment Clock ESMC: Ethernet Synchronization Messaging Channel QL: Quality Level SASE: Stand Alone Synchronization Equipment SSM: Synchronization Status Messaging