A supervisor entity comprises an entity status module for maintaining status of its subordinate entities and updating the supervisor entity with status updates for itself and the subordinate entities. The entity status module comprises an entity status controller for receiving a status message from a first subordinate entity, a subordinate determination module for determining a second subordinate entity that is subordinate to the first subordinate entity, a status update module for updating the status of the second subordinate entity based on the received status message from the first subordinate entity, a status reporting module for reporting the updated status of the second subordinate entity to a supervisor entity and a status storage for storing the status of the second subordinate entity.