This reflects whether an operator has administratively enabled this dynamically-signaled co-routed bidirectional tunnel, which also gates whether RSVP-TE is even permitted to attempt signaling both directions of this circuit. An admin disabling this stops signaling attempts for the entire two-way circuit at once, not just one leg, which is the key operational difference from disabling one leg of an associated tunnel pair. For example, disabling this during planned maintenance prevents the circuit from attempting any re-signal in either direction while the admin works on the shared path.