This value specifies, together with tmnxDot1agCfmMepFacilityIfIndex and tmnxDot1agCfmMepFacilityVlanId, whether a MEP is a facility MEP and if so what kind: nonFacilityType(0) meaning it isn't one, port(1) for a port/LAG-level MEP, or interface(2) for a router-interface-level MEP; it can't be changed once set. An admin sets this when creating a facility MEP to declare exactly what class of underlying transport the MEP monitors, as distinct from monitoring a specific customer-facing service. A value of nonFacilityType(0) is the default for ordinary (non-facility) MEPs attached via the usual interface or service objects instead.