This specifies whether this VLLI group propagates fault indication in only one direction, from a monitored source toward a dependent action point, or bidirectionally, where either side reacts to the other's fault, which determines the actual failover behavior an admin should expect during a real fault. An admin designing a protection scheme where only one side should ever act on the other's failure, say an access device shutting down when it loses its uplink but not vice versa, would configure this as unidirectional rather than bidirectional. For example, a bidirectional configuration on a scheme intended to be one-way could cause an unexpected shutdown on the wrong side when only one direction's failure was actually intended to trigger action.