A first node device transmits to a second node device unique identification information corresponding to specific common information, receives from the information saving node device the relevant information regarding the information saving node device, and requests to a selected information saving node device delivery of the specific common information, the second node device searches the node information and, in a case where there is node information, transfers the identification information to the information saving node device, which is indicated by node information, and the information saving node device, in a case where the transmission of the specific common information indicated by the identification information is available, transmits to the first node device the relevant information regarding the information saving node device, and, in a case where delivery request for the specific common information is received from the first node device, delivers specific common information.