REMOVABILITY CONTROL DEVICE, TREE-TYPE DISTRIBUTION SYSTEM, NODE DEVICE REMOVAL CONTROL METHOD, STORAGE MEDIUM STORING REMOVABILITY CONTROL PROGRAM, AND STORAGE MEDIUM STORING INFORMATION PROCESSING PROGRAM

摘要

A removability control device for controlling the removal timing of a participating node device in the whole of a tree-type distribution system in which the topology connection state is varying constantly and preventing topology collapse to realize a high-stability tree-type distribution system. The removability control device for controlling the removability from a tree-type distribution system acquires the number of node devices participating in the system, determines a simultaneous removal processing upper limit number which is the number of node devices simultaneously removable according to the number of participating node devices, judges if the number of node devices being subjected to removal processing has reached the simultaneous removal processing upper limit or not when receiving a removal request information representing a request of a node device for removal from the system, transmits removal permission notification to permit removal processing to the node device which has transmitted the removal request information when the number of nodes being subjected to removal processing has not reached the simultaneous removal processing upper limit number yet, and does not transmit any removal permission notification when the number has reached the simultaneous removal processing upper limit number.