This read-only value reports whether the PNNI controller referenced in a trap is active, standby, or unavailable, and the MIB explicitly notes that performing a plain SNMP get on it is meaningless -- it only has meaning as a variable bound to a trap. It lets an admin's trap-receiving system determine, at the moment a PNNI controller event fires, exactly which role that controller held. For example, a network management station receiving a controller-switchover trap would read this varbind to log whether the reporting controller had just become active or gone unavailable.