802.3ah EFM OAM declares a link fault when any of the following occurs:
loss of OAMPDU for a certain period of time
receiving OAMPDU with link fault flags from the peer
When 802.3ah EFM OAM declares a fault, the port goes into operation state down. The SMGR communicates the fault to CFM MEPs in the service. OAM fault propagation in the opposite direction (SMGR to EFM OAM) is not supported.