Overview of Y.1731
Ethernet in the First Mile (EFM) and Connectivity Fault Management (CFM) are used to detect link faults for carriers. Y.1731, an enhancement of CFM, can be configured to monitor service performance.
Hierarchical Ethernet operation, administration and maintenance (OAM) needs to be provided based on the network architecture, as shown in Figure 1.
Y.1731 is an OAM protocol defined by the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T). It covers items defined in IEEE 802.1ag and provides additional OAM messages for fault management and performance monitoring. Fault management includes alarm indication signal (AIS), remote defect indication (RDI), locked signal (LCK), test signal, automatic protection switching (APS), maintenance communication channel (MCC), experimental (EXP) OAM, and vendor specific (VSP) OAM. Performance monitoring includes frame loss measurement (LM) and delay measurement (DM).