CFS has an obligation to notify NPWS of any fire in or adjoining their parks, including the dispatch of NPWS crews.
They are a great resource, although not always there for the initial attack, as they are paid they are there to do the mop up and patrolling to let us get home, back to work or to get a life.
Great cooperation is probaly because many of them are already CFS members. Further as registered CFS brigades the NPWSA crews will fit into any operations.