Abstract: 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.

Abstract: The present invention provides a distribution system in which even in the case where the content distributability varies among content holders, desired content can be promptly and efficiently received by a requester. To index information recorded in a root node or cache node so that it can be referred to from the requester, in addition to content ID and IP address of a content holder, easiness information indicative of easiness of distribution of content from the content holder are added. When the requester determines a content holder as a distribution source, a content holder having high distributability is preferentially selected with reference to the easiness information and content is distributed from the selected content holder.

Abstract: In a first node in a system having nodes connected to each other as a network, request information including identification information and request number of location information indicating a location in the network of information saving nodes is transmitted to a second node. In the second node, the location information and identification information are saved. At least the location information whose number corresponds to the request number is transmitted to the first node when the number of the saved location information meets the request number. Otherwise, the location information whose number corresponds to the number of the saved location information is transmitted to the first node. The received request information is transferred when the second node itself is not a management node, to a node interposed between the second node and the management node, or to the management node when there is no node therebetween.

Abstract: The present invention enables replicas of the necessary number in a distribution system to be disposed autonomously in proper positions in the distribution system without providing a server or the like and enables necessary content to be distributed more efficiently. One or plural pieces of content is/are recorded in nodes N1 to N4 as components of a distribution system in which content C1 to C4 to be distributed are directly transmitted/received among the nodes N via a network. An evaluation value having a value based on at least the number of distribution requests is generated and stored for each piece of the content C1 to C4.

Abstract: The present invention provides a distribution system in which even in the case where the content distributability varies among content holders, desired content can be promptly and efficiently received by a requester. To index information recorded in a root node or cache node so that it can be referred to from the requester, in addition to content ID and IP address of a content holder, easiness information indicative of easiness of distribution of content from the content holder are added. When the requester determines a content holder as a distribution source, a content holder having high distributability is preferentially selected with reference to the easiness information and content is distributed from the selected content holder.

Abstract: In an information delivery system including a plurality of node devices connected each other to thereby configure a network, a first node device includes a device for transmitting request information based on unique identification information corresponding to specific common information and request number information indicative of request number of node information to a second node device to thereby request transmission of the node information concerning a plurality of information saving node devices, included in the plurality of node devices and saving specific common information, which is specified out of common information to be shared among the plurality of node devices, and the second node device includes : a device for searching node information corresponding to the identification information and indicated by request number information included in the request information as many as request number upon receipt of request for the specific common information and a device for transmitting the node informati

Abstract: 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.