802.3ah is a link level Metro Ethernet OAM which is used for the last mile monitoring purpose. It cannot scale more than a single hop. It can transmit at max rate of 10 frames per second which is equivalent to 100ms transmission time for single frame. At least we need 3 frames to detect the link loss with high cpu usage which will contribute almost 300ms to acheive only link level convergence time.
Remote Failure Indication remote loopback
Port Level Loopback
Perfomrance and Status Monitoring