Persistency is available for subscriber’s ANCP attributes and is stored on the on-board compact flash card. ANCP data stays persistence during an ISSU as well as nodal reboots. During recovery, ANCP attributes are first restored fully from the persistence file and incoming ANCP sessions are temporarily on hold. Afterwards new ANCP data can overwrite any existing values. This new data is then stored into the compact flash in preparation for the next event.