JP5338783B2 - Information communication system, node device, information communication method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information communication system, a node device, an information communication method, a program and the like capable of operating a P2P system even in an environment in which IPv4 and IPv6 coexist. <P>SOLUTION: A contact node device which received a participation message from a participating node device B transmits node information of a first node device stored by the contact node device to a participating node device B. The participating node device B which received the node information of the first node device is connected to the first node. The participating node device B is connected to the first node device based on the IP address included in the node information of the first node device. At this time, a session is established between the participating node device B and the first node device. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a technical field of a peer-to-peer (P2P) communication system including a plurality of node devices that can communicate with each other via a network.

  In recent years, a peer-to-peer communication system as disclosed in Patent Document 1 has attracted attention. The peer-to-peer communication system is attracting attention as a new form that replaces the server client system, which is the mainstream form of current content distribution. In this peer-to-peer communication system, content requests to the server device at the center are not concentrated. Therefore, content can be acquired in a short time compared to the server client method. Specifically, Patent Document 1 discloses a technique in which a plurality of DHT (Distributed Hash Table) routing tables are generated for each group in units of software.

JP 2008-217135 A

  In recent years, with the depletion of IPv4 (Internet Protocol Version 4) address resources, the transition to IPv6 (Internet Protocol Version 6) is progressing. In the process of transitioning from IPv4 to IPv6, both IPv4 and IPv6 protocols may coexist in the network. When a P2P (Peer to Peer) type system operates in a network environment in which IPv4 and IPv6 coexist, different protocols are assigned to node devices connected to the P2P system. For example, IPv4 is assigned to a certain node device A, and IPv6 is assigned to a node device B different from the node device A. In this case, when the node device A and the node device B perform data communication by P2P, they cannot communicate because the protocol is different, and the P2P system cannot be operated.

  The present invention has been made in view of the above points. An object of the present invention is to provide an information communication system, a node device, an information communication method, a program, and the like that can operate a P2P system even in a network environment in which IPv4 and IPv6 coexist.

  According to the first aspect of the present invention, there is provided an information communication system that transmits and receives a plurality of data stored in a distributed manner by an overlay network including a plurality of node devices, and any one of the plurality of node devices. The node device is a first overlay network composed of at least a part of node devices communicable with IPv4, and the location of the node device participating in the first overlay network is determined on the network. A first routing table in which location information to be indicated is registered, or a second overlay network configured by at least a part of node devices of node devices communicable with IPv6, and a node device participating in the second overlay network The second rooty in which the location information is registered A first storage unit that stores one of the routing tables in the routing table, and a second storage device that is capable of communicating with both IPv4 and IPv6, which are any of the plurality of node devices, and the node device can communicate with. A second storage means for storing location information indicating the location of the one-node device in the network; and a participation message transmitted from the participating node device participating in the information communication system and indicating participation in the information communication system, Receiving means for receiving the participation message including protocol information indicating IPv4 or IPv6, which is a protocol with which the participating node device can communicate, and participation from the participating node device participating in the information communication system, indicating participation in the information communication system A protocol that is a participation message that the participating node device can communicate with. A receiving unit that receives the participation message including protocol information indicating IPv4 or IPv6, and a protocol of the routing table in which the protocol information included in the participation message received by the receiving unit is stored in the first storage unit When it is determined by the determination means that it is matched with the determination means, at least a part of the routing table determined to be matched is transmitted to the participating node device, and is determined to be matched by the determination means And a transmission unit that transmits the location information of the first node device stored in the second storage unit to the participating node device when it is not.

  According to a second aspect of the present invention, the participating node device is acquired by the first acquisition unit that acquires the location information of the first node device transmitted by the transmission unit, and the first acquisition unit. A first generation unit configured to generate a session to the first node device indicated by the location information using a protocol communicable with the participating node device, wherein the first node device includes the first generation unit. A request receiving means for receiving a request for the predetermined data from the participating node device for which a session has been generated by the step, and the overlay network in which the second storage means stores the data requested by the request receiving means. A second requesting means for requesting, and any of node devices for connecting the data requested by the second requesting means to the overlay network A second obtaining unit configured to take acquired the said data acquired by the data acquisition unit, characterized in that it comprises a relay means for relaying to the participating node device.

According to a third aspect of the present invention, the participating node device includes a third storage unit that stores the data, and a disclosure unit that discloses the data stored in the third storage unit via the overlay network; Search means for searching the data published by the publication means using the overlay network before the data is published by the publication means;
And when the data to be published is not retrieved by the retrieval means, the publication means publishes the data.

  According to a fourth aspect of the present invention, when the protocol information included in the participation message received by the receiving means indicates that communication is possible with both IPv4 and IPv6, the second storage means The location information of the participating node device is stored using the participating node device as the first node device.

  According to the fifth aspect of the present invention, any one of the plurality of node devices included in an information communication system that transmits and receives a plurality of data stored in a distributed manner by an overlay network including a plurality of node devices. A first overlay network composed of at least a part of node devices that can communicate with IPv4, and the location of the node devices participating in the first overlay network on the network A first routing table in which location information to be indicated is registered, or a second overlay network configured by at least a part of node devices of node devices communicable with IPv6, and a node device participating in the second overlay network The second route where the location information is registered A first storage means for storing one of the routing tables in the routing table and a first storage means capable of communicating with both IPv4 and IPv6, which are any of the plurality of node devices, and the node device can communicate with. A second storage means for storing location information indicating the location of the one-node device in the network; and a participation message transmitted from the participating node device participating in the information communication system and indicating participation in the information communication system, Receiving means for receiving the participation message including protocol information indicating IPv4 or IPv6, which is a protocol with which the participating node device can communicate, and participation from the participating node device participating in the information communication system, indicating participation in the information communication system Prototype message that can be communicated by the participating node device Receiving means for receiving the participation message including protocol information indicating IPv4 or IPv6, and the protocol information included in the participation message received by the receiving means in the routing table stored by the first storage means When it is determined by the determination unit that determines whether or not the protocol matches, the determination unit transmits at least a part of the routing table determined to match to the participating node device. A transmission device that transmits the location information of the first node device stored in the second storage device to the participating node device when the determination is not made.

  According to the sixth aspect of the present invention, a plurality of data stored in a distributed manner is transmitted / received by an overlay network including a plurality of node devices, and is executed by any one of the plurality of node devices. IPv4, which is a participation message transmitted from a participating node device participating in the information communication system and indicating participation in the information communication system, and is a protocol with which the participating node device can communicate Or a reception step of receiving the participation message including protocol information indicating IPv6, and a first overlay network configured by at least some of the node devices communicable with IPv4, wherein the first overlay network includes Location of participating node devices on the network A first routing table in which location information to be indicated is registered, or a second overlay network configured by at least a part of node devices of node devices communicable with IPv6, and a node device participating in the second overlay network The routing table protocol stored in the first storage means for storing any one routing table of the second routing table in which the location information is registered, and the protocol information included in the participation message received in the receiving step; A determination step for determining whether or not the two match, and when it is determined to match according to the determination step, at least a part of the routing table determined to match is transmitted to the participating node device, and it is determined to match according to the determination step Is When this happens, the location information indicating the location in the network of the first node device which is one of the plurality of node devices and which can communicate with both IPv4 and IPv6 which is a protocol with which the node device can communicate is stored. A transmission step of transmitting the location information of the first node device stored in the second storage means to the participating node device.

  According to the seventh aspect of the present invention, a plurality of pieces of data stored in a distributed manner are transmitted and received by an overlay network including a plurality of node devices, and the computer of the node device of any of the plurality of node devices A participation message transmitted from a participating node device participating in the information communication system and indicating participation in the information communication system, and protocol information indicating IPv4 or IPv6, which is a protocol with which the participating node device can communicate. A reception step for receiving the participation message, and a first overlay network composed of at least some of the node devices communicable with IPv4, the network of the node devices participating in the first overlay network Location information indicating the above location is registered The first routing table or the second overlay network configured by at least a part of node devices of node devices capable of communicating with IPv6, wherein the location information of the node devices participating in the second overlay network is Whether the protocol of the routing table stored by the first storage means for storing any one of the registered second routing tables matches the protocol information included in the participation message received by the receiving step When it is determined by the determination step and the determination step to match, at least a part of the routing table determined to match is transmitted to the participating node device, and when it is not determined to match by the determination step, Said compound Is stored in second storage means for storing location information indicating the location in the network of the first node device that can communicate with both IPv4 and IPv6, which is a protocol that can communicate with the node device. A transmission step of transmitting the location information of the first node device to the participating node device.

  According to the first aspect of the present invention, the determination unit determines whether the protocol information included in the participation message received by the reception unit matches the protocol of the routing table stored by the first storage unit. When it is determined by the determining means that they match, the transmitting means transmits at least a part of the routing table determined to match to the participating node devices. Then, when the determination means does not determine that they match, the transmission means transmits the location information of the first node device stored in the second storage means to the participating node device. Therefore, when the protocol communicable in the routing table matches the protocol of the participating node device, the participating node device can participate using the acquired routing table using the overlay network. Further, when the protocol that can be communicated in the routing table does not match the protocol of the participating node device, the location information of the node device that can communicate with both IPv4 and IPv6 can be acquired. As a result, even a node device that can communicate only with either IPv4 or IPv6 can operate the 2P system in a network environment in which IPv4 and IPv6 coexist.

  According to a second aspect of the present invention, the first node device includes second acquisition means for acquiring the data requested by the second request means from any of the node devices connected to the overlay network. Also. The first node device includes a relay unit that relays the data acquired by the data acquisition unit to the participating node device. Therefore, even if the protocol that can be communicated with the routing table does not match the protocol of the participating node device, a session is generated with the node device that can communicate with both IPv4 and IPv6, and communication is performed. be able to. As a result, a node device that can communicate with both IPv4 and IPv6 can relay data to a node device that can communicate only with either IPv4 or IPv6. Therefore, the 2P system can be operated in a network environment where IPv4 and IPv6 coexist.

  The participating node device may be a node device that can communicate only with either IPv4 or IPv6. Therefore, it is necessary to relay data to the participating node devices. In order to communicate data stably, the participating node devices should refrain from uploading data as much as possible. According to a third aspect of the present invention, the participating node device comprises a publishing unit that publishes the data stored in the third storage unit on the overlay network. Further, when the data disclosed by the search means is not searched, the release means releases the data. As a result, when the data cannot be retrieved by the retrieval means, the data is released, so that the participating node devices can refrain from uploading data as much as possible, prevent occurrence of relay processing, and communicate efficiently.

  According to the fourth aspect of the present invention, when the protocol information included in the participation message received by the receiving unit indicates that communication is possible in both IPv4 and IPv6, the second storage unit stores the participating node device. As the first node device, location information of the participating node device is stored. As a result, when the node device participates in the information communication system, it is possible to know the node device that can communicate with both IPv4 and IPv6.

  According to the fifth aspect of the present invention, the determination unit determines whether the protocol information included in the participation message received by the reception unit matches the protocol of the routing table stored by the first storage unit. When it is determined by the determining means that they match, the transmitting means transmits at least a part of the routing table determined to match to the participating node devices. Then, when the determination means does not determine that they match, the transmission means transmits the location information of the first node device stored in the second storage means to the participating node device. Therefore, when the protocol communicable in the routing table matches the protocol of the participating node device, the participating node device can participate using the acquired routing table using the overlay network. Further, when the protocol that can be communicated in the routing table does not match the protocol of the participating node device, the location information of the node device that can communicate with both IPv4 and IPv6 can be acquired. As a result, even a node device that can communicate only with either IPv4 or IPv6 can operate the 2P system in a network environment in which IPv4 and IPv6 coexist.

  According to the sixth aspect of the present invention, the transmission step transmits at least a part of the routing table determined to be coincident to the participating node device when it is determined to coincide with the decision step. In addition, when the transmission step is not determined to match by the determination step, the first node is one of a plurality of node devices and can communicate with both IPv4 and IPv6, which are protocols with which the node device can communicate. The location information of the first node device stored in the second storage means for storing the location information indicating the location of the device in the network is transmitted to the participating node device. Therefore, when the protocol communicable in the routing table matches the protocol of the participating node device, the participating node device can participate using the acquired routing table using the overlay network. Further, when the protocol that can be communicated in the routing table does not match the protocol of the participating node device, the location information of the node device that can communicate with both IPv4 and IPv6 can be acquired. As a result, even a node device that can communicate only with either IPv4 or IPv6 can operate the 2P system in a network environment in which IPv4 and IPv6 coexist.

  According to the seventh aspect of the present invention, the transmission step transmits at least a part of the routing table determined to be coincident to the participating node device when it is determined to coincide with the decision step. In addition, when the transmission step is not determined to match by the determination step, the first node is one of a plurality of node devices and can communicate with both IPv4 and IPv6, which are protocols with which the node device can communicate. The location information of the first node device stored in the second storage means for storing the location information indicating the location of the device in the network is transmitted to the participating node device. Therefore, when the protocol communicable in the routing table matches the protocol of the participating node device, the participating node device can participate using the acquired routing table using the overlay network. Further, when the protocol that can be communicated in the routing table does not match the protocol of the participating node device, the location information of the node device that can communicate with both IPv4 and IPv6 can be acquired. As a result, even a node device that can communicate only with either IPv4 or IPv6 can operate the 2P system in a network environment in which IPv4 and IPv6 coexist.

It is a figure which shows an example of the connection mode of each node apparatus Tm-n in the information communication system S in this embodiment. It is explanatory drawing which shows description of the participating process of the participating node apparatus A and the participating node apparatus B. FIG. 6 is an explanatory diagram illustrating a description of a participation process of a participating node device C. FIG. It is a block diagram which shows the electrical constitution of the contact node of this embodiment. It is a block diagram which shows the electric constitution of the node apparatus of this embodiment, and a 1st node apparatus. It is a flowchart which shows the process sequence of the contact node main operation | movement in a contact node. It is a flowchart which shows the process sequence of the node apparatus main operation | movement in a node apparatus and a 1st node apparatus. It is a flowchart which shows the process sequence of a participating message process. It is a flowchart which shows the process sequence of a publish process.

[Best Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to a peer-to-peer information communication system.

[Outline configuration of information communication system]
First, the schematic configuration of the information communication system S in the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a connection mode of each node device in the information communication system S according to the present embodiment.

  As shown in FIG. 1, the information communication system S is composed of a plurality of node devices Tm-n (any of n = 1, 2, 3,...). The plurality of node devices Tm-n can communicate with each other via the network NW. This network NW is a real-world communication network. For example, the Internet.

The network NW is a network for interconnecting the base networks NLm (m = 1, 2, 3,...). The network NW is, for example, the Internet or a WAN (Wide Area Network). The network NW is, for example,
It is constructed by IX (Internet Exchange), ISP (Internet Service Provider), DSL (Digital Subscriber Line) line provider equipment, FTTH (Fiber To The Home) line provider equipment, communication lines, and the like. The network NW may be a network dedicated to the information communication system S.

  In the present embodiment, one or more base networks NLm are formed in the network NW. In addition, a plurality of node devices Tm-n (n = 1, 2, 3...) Are connected to each base network NLm. Each base network NLm is a network constructed in the site of the base m. The bases include, for example, a company, a school, a hospital, a cram school, and a karaoke box. This base network NLm is constructed by a LAN or the like, for example. Alternatively, the base network NLm may be a network constructed by interconnecting a plurality of LANs. In this case, the plurality of LANs are connected via a network device such as a router. An example of a network in which a plurality of LANs are interconnected is CAN (Campus Area Network). A firewall FW or a broadband router BR is connected to each base network NLm. The firewall FW or the broadband router BR is a communication device that enables communication between a node device Tm-n connected in the base and a node device Tm-n other than the node device Tm-n connected to the base. Since the firewall FW or the broadband router BR is publicly known, detailed description thereof is omitted. Which of the firewall FW and the broadband router BR is installed at a base is arbitrarily determined for each base. The base network NLm of this embodiment is, for example, a LAN (Local Area Network).

  In addition, a center server and an input server are connected to the network NW. The center server and the input server are not particularly shown. The center server stores the original content data transmitted / received in an overlay network OL described later. Further, the center server transmits the content catalog information to the node device Tm-n. Details of the content catalog information will be described later. The input server is a server device that inputs content data to an overlay network OL described later. Here, the input of content data refers to placing content data in a state where it can be acquired from the node device Tm-n. The content data is referred to as “content”.

  Each node device Tm-n is assigned a unique serial number and an IP (Internet Protocol) address. In the present embodiment, the node device Tm-n includes a node device that can communicate only with IPv4, a node device that can communicate only with IPv6, and a node device that can communicate with both IPv4 and IPv6.

  Each node device Tm-n connected to the information communication system S is assigned a node ID, which is unique identification information having a predetermined number of digits. In the information communication system S of the present embodiment, an overlay network OL for content distribution is constructed. The overlay network OL is an overlay network constructed on the network NW. In other words, the overlay network OL is a logical network generated on a physical network. The overlay network OL is realized by a specific algorithm, for example, an algorithm using a distributed hash table. Hereinafter, the distributed hash table is referred to as “DHT (Distributed Hash Table)”. Note that a routing table using DHT is known in Japanese Patent Application Laid-Open No. 2006-197400.

  In the present embodiment, port forwarding may be set in the broadband router BR and the firewall FW so that each node device Tm-n can perform communication in a peer-to-peer manner. For example, in the case of a broadband router BR, it is preferable to set port forwarding automatically using a UPnP (Universal Plug and Play) function or the like. Hereinafter, the node device Tm-n is simply referred to as a node device.

[How to participate in Overlay Network OL]
Each node device participating in the overlay stores a routing table using DHT. This routing table defines the transfer destinations of various control messages on the information communication system S. The control message is a message for controlling the operation of the P2P information communication system. In other words, the control message is a message for use in content search or content acquisition in a P2P information communication system. The control message is a message transmitted / received according to the DHT routing table. Specifically, a plurality of pieces of node information including node IDs, IP addresses, and port numbers of node devices that are moderately separated in the ID space are registered in this routing table. One node device connected to the information communication system S stores the minimum necessary node information of the node device as a routing table. By transferring control messages between the node devices, node information about node devices that do not store node information is acquired. Further, the information communication system S can operate as a peer-to-peer type information communication system by transmitting and receiving the control message by each node device.

  In the present embodiment, the overlay network OL is formed by participation of node devices that can communicate with IPv4. Therefore, a node device that can communicate only with IPv6 cannot participate in the overlay network OL. In this embodiment, the overlay network OL is formed by node devices that can communicate with IPv4. However, the present invention is not limited to this. For example, the overlay network OL may be formed by node devices that can communicate with IPv6. In this case, a node device that can communicate only with IPv4 cannot participate in the overlay network OL. In addition, when there are more node devices to which IPv6 is assigned than IPv4 among node devices participating in the information communication system S, the overlay network OL may be formed by node devices that can communicate with IPv6. When there are more node devices to which IPv4 is assigned than IPv6 among node devices participating in the information communication system S, the overlay network OL may be formed by node devices that can communicate with IPv4.

  In connection with the information communication system S, a node device not connected to the information communication system S transmits a participation message indicating a request to participate in the information communication system S to any connected node device. Is done by. Participation in the information communication system S means that the node device is connected to the information communication system S and can acquire content data from the information communication system S. The arbitrary node device is, for example, a contact node that is always connected to the information communication system S. The node device that participates in the information communication system S transmits a participation message to the contact node, so that the node device can acquire the DHT routing table from the contact node. Hereinafter, an outline of the participation process of the present embodiment will be described.

[About the participation process overview]
2 and 3 are explanatory diagrams for explaining the participation process of the present embodiment. In the present embodiment, a node device newly participating in the overlay network OL is referred to as a participating node device. The participating node devices of the present embodiment include node devices that can communicate only with IPv4, node devices that can communicate only with IPv6, and node devices that can communicate with both IPv4 and IPv6. First, a description will be given of a node device participation process capable of communicating only with IPv4. Hereinafter, as shown in FIG. 2, a participating node device capable of communicating only with IPv4 is referred to as a participating node device A.

(Participation processing of participating node device A)
First, in order for the participating node device A to participate in the overlay network OL, the participating node device A transmits a participation message to the contact node (FIG. 2: arrow (1)). The participation message of this embodiment includes node information of the participating node device A and version information of the node device Tm-n that has transmitted the participation message. The version information is information indicating the protocol of the node device. For example, the participating node device A is a node device that can communicate only with IPv4. In this case, the version information of the participating node device A is information indicating IPv4. The participating node device B is a node device that can communicate only with IPv6. In this case, the version information of the participating node device B is information indicating IPv6. In addition, the participating node device C is a node device that can communicate with both IPv4 and IPv6. For this reason, the version information of the participating node device C is information indicating IPv4 and IPv6. By including the version information in the participation message, the contact node can grasp a protocol with which the participating node device can communicate. The version information of the participating node device A indicates IPv4. Therefore, the contact node device receives a participation message including version information indicating IPv4 from the participating node device A. Note that the contact node of the present embodiment is a node device that can communicate with both IPv4 and IPv6. The version information of this embodiment is an example of the protocol information of the present invention.

  Then, the contact node that has received the participation message determines whether there is information that matches the version information of the node device forming the overlay network OL in the version information included in the participation message. Specifically, in this embodiment, the overlay network OL is formed by node devices that can communicate with IPv4. Therefore, it is determined whether there is information that matches IPv4 in the version information included in the participation message. When it is determined that there is information that matches IPv4 in the version information, the DHT routing table stored in the contact node is transmitted to the participating node device A. In the present embodiment, since the participating node device A is a node device that can communicate only with IPv4, a DHT routing table is transmitted from the contact node device to the participating node device A (FIG. 2: arrow (2)). In this embodiment, the participating node device A receives the DHT routing table from the contact node, but is not limited to this. For example, the participating node device A may receive a part of the DHT routing table from the contact node. In this case, based on the received part of the DHT routing table, the participating node device A may acquire the remaining DHT routing tables from other node devices.

  Then, based on the DHT routing table, the participating node device A participates in the overlay network OL (FIG. 3: arrow (3)). Note that to participate in the overlay network OL means to operate in a state where various messages can be transmitted to and received from other node devices via the overlay network OL based on a routing table using DHT.

(Participation processing of participating node device B)
Next, an outline of the participation process of the participating node device B will be described. In order for the participating node device B shown in FIG. 2 to participate in the overlay network OL, the participating node device B transmits a participation message to the contact node (FIG. 2: arrow (4)). The version information of the participating node device B indicates IPv6. Therefore, the contact node receives a participation message including version information indicating IPv6 from the participation node apparatus B.

  Then, the contact node that has received the participation message determines whether there is information that matches the version information of the node device forming the overlay network OL in the version information included in the participation message. Specifically, in this embodiment, the overlay network OL is formed by node devices that can communicate with IPv4. Therefore, it is determined whether there is information that matches IPv4 in the version information included in the participation message. In this embodiment, since the participating node device B is a node device that can communicate only with IPv6, the participating node device B cannot participate in the overlay network OL. At this time, the contact node transmits the node information of the first node device to the participating node device B. The first node device according to the present embodiment is a node device that can communicate with both IPv4 and IPv6. The contact node stores node information of the first node device. The contact node that has received the participation message from the participating node device B transmits the node information of the first node device stored in the contact node to the participating node device B. (FIG. 2: Arrow (5)).

  The participating node device B that has received the node information of the first node device connects to the first node (FIG. 2: arrow (6)). Based on the IP address included in the node information of the first node device, the participating node device B connects to the first node device. At this time, a session is established between the participating node device B and the first node device (FIG. 2: arrow (7)).

  Hereinafter, the session establishment of this embodiment will be specifically described. The participating node device B that has established the session transmits and receives a P2P control message to and from the first node device that has established the session. Once the session is established, the participating node device B and the first node device hold the session even after receiving or transmitting the control message. The session is held by registering session information in a socket table provided in a predetermined storage area of the first node device. The session information may include, for example, the node information of the first node device itself that stores the socket table, the node information of the connecting node device B that is the connection destination, and the socket identifier. Note that the “socket table” here is not a well-known one, but is implemented for the present embodiment. The socket table is information in which an IP address is associated with a node ID.

  A plurality of session information can be registered in the socket table. Thereby, a session with a plurality of node devices can be held. However, the number of sockets is limited. For example, it is about 60-120. Therefore, when the number of session information registered in the socket table exceeds a predetermined number, it is deleted from the least used session information. For example, the session information is deleted from the socket table by an LRU (Last Recently Used) method.

  Specifically, a socket table is set in the first node device. When the participating node device B receives the transmission source message, the first node device associates the node ID of the transmission participating node device B with the IP address and port number of the participating node device B in the socket table. sign up. For example, it is assumed that the first node device accepts a session start from the participating node device B and a session is established. At this time, it is assumed that a control message addressed to a node device other than the first node device, which is a control message having the participating node device B as a transmission source, is received by the first node device. In this case, the first node device associates the node ID of the participating node device B with the IP address and port number of the participating node device B and registers them in the socket table.

  Then, the first node device rewrites the IP address included in the node information of the participating node device B that is the transmission source included in the control message with the IP address of the first node device. That is, the first node device uses the IP address of the source node device included in the control message as the IP address of the first node. By rewriting the IP address in this way, the node device that has received the relayed control message can return the control message to the first node device.

  In addition, the first node device may receive a control message that is transmitted from any one of the node devices participating in the overlay network OL. At this time, the first node determines whether or not the received control message is a control message transmitted to the participating node device B in session holding state with the first node device. First, it is determined whether the node ID indicating the destination of the received control message matches the node ID of the first node device. If they do not match, it is determined whether or not the node ID indicating the destination of the received control message is registered in the socket table. If registered in the socket table, it is determined that the received message is a message addressed to the participating node apparatus B. Then, the first node device relays the control message to the participating node device B indicated by the IP address registered in the socket table. On the other hand, if it is not registered in the socket table, the received control message is transferred to another node device based on the DHT routing table.

  Thus, the destination of the control message is rewritten by the first node device to the node information of the participating node device B registered in the socket table in association with the node ID of the participating node device B. As a result, the control message transmitted with the participating node device B as the destination is relayed by the first node device and transmitted to the participating node device B.

  Note that the node ID, IP address, and port number of the participating node device B registered in this way are used when the session with the participating node device B is disconnected, the first node device with the participating node device B Delete information from the socket table. The disconnection of the session means that the session information is deleted from the storage unit of the first node device. Thus, even a node device that cannot communicate with IPv4 that can communicate with the overlay network OL can communicate with the overlay network OL by forming a session with the first node device.

(Outline of participation process of participating node apparatus C)
FIG. 3 is an explanatory diagram showing an outline of the participation process of the participating node device C. First, in order for the participating node device C to participate in the overlay network OL, the participating node device C transmits a participation message to the contact node (FIG. 2: arrow (8)). The participation message of this embodiment includes node information of the participating node device C and version information of the node device that has transmitted the participation message. The version information of the participating node device C indicates IPv4 and IPv6. Therefore, the contact node device receives a participation message including version information indicating IPv4 and IPv6 from the participating node device C.

  Then, the contact node that has received the participation message determines whether there is information that matches the version information of the node device forming the overlay network OL in the version information included in the participation message. Specifically, in this embodiment, the overlay network OL is formed by node devices that can communicate with IPv4. Therefore, it is determined whether there is information that matches IPv4 in the version information included in the participation message. When it is determined that there is information matching IPv4 in the version information, the DHT routing table stored in the contact node is transmitted to the participating node device C. In this embodiment, since the participating node device C is a node device that can communicate with both IPv4 and IPv6, the DHT routing table is transmitted from the contact node device to the participating node device C (FIG. 2: arrow (9)). ). In addition, the contact node that has received the participation message determines whether the version information indicates both IPv4 and IPv6. When it is determined that the version information indicates both IPv4 and IPv6, the contact node registers the participating node device C as the first node device. Specifically, the contact node stores the node information of the participating node device C included in the participation message as the first node device. In this way, the contact node device can transmit the node information of the first node device to the participating node device B.

  Then, based on the DHT routing table, the participating node device C participates in the overlay network OL (FIG. 3: arrow (10)).

[Outline of content acquisition operation]
In the information communication system S, various content data having different contents are distributed and stored in a plurality of node devices. Each content data is provided with a content ID that is unique identification information for each content name and content data. Attribute information such as content name and content ID of each content is described in the content catalog information. The content catalog information is created by the center server and distributed to all node devices. Each content is divided into a plurality of data. This divided data is called “chunk”. Each chunk is generated, for example, by dividing the content with a predetermined data size by the center server. In the present embodiment, the minimum data size of a chunk is 2 MB (Mega Byte). The maximum data size of the chunk is 128 MB. However, as a result of division into chunks, some chunks may be smaller than 2 MB. In addition, if the data size before being divided into chunks is originally smaller than 2 MB, the chunk may have a data size of less than 2 MB. In the present embodiment, the content data is divided into a plurality of chunks. As described in the present embodiment, the content data may not be divided into a plurality of chunks. Content data that is not divided may be applied to the present embodiment.

  Each chunk is distributed and stored in a plurality of node devices. As a result, the original content is distributed and stored in a plurality of node devices. The original of each chunk is stored in the center server. Each chunk is given a sequence number and a chunk ID. The sequence number corresponds to, for example, an arrangement order when a plurality of divided chunks are arranged so as to constitute the original content. The chunk ID is identification information unique to each chunk.

  When each node device acquires a content ID of a certain content, each node device can acquire the chunk ID of each chunk constituting the content in association with the sequence number. For example, in the content catalog information, the chunk ID of each chunk constituting the content may be described in association with the sequence number in the attribute information of the original content.

  A node device that stores chunks is referred to as a “content holding node”. Further, the location of the chunk is stored as index information by the node device that manages (stores) the location of the chunk. Hereinafter, the node device that manages the location of the chunk is referred to as a “root node”. The index information includes a set of node information of the node device that stores the chunk, a chunk ID of the chunk, and the like. Such a root node is determined to be a node Nn having a node ID closest to the chunk ID, for example. The node ID closest to the chunk ID is, for example, a node ID with the highest number of upper digits of the ID.

  When a user of a certain node device wants to acquire desired content, the node device searches for a content holding node that stores each chunk constituting the desired content. Hereinafter, a node device that a user desires to acquire a chunk is referred to as a “user node”. Specifically, the user node transmits a search message. This search message includes the chunk ID of the chunk desired to be acquired and the node ID of the user node. This search message is transmitted to other node devices according to the DHT routing table stored in the user node. That is, the user node transmits a search message toward the root node. As a result, the search message finally arrives at the root node by DHT routing using the chunk ID as a key. The DHT routing is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  The root node that has received the search message acquires one or more index information corresponding to the chunk IDs included in the search message from the index information cache. The acquired index information is returned to the user node that is the source of the search message. The user node that has acquired the index information in this way acquires (downloads) a chunk based on the index information. Specifically, the user node transmits a chunk request message to the content holding node based on the IP address and port number of the content holding node included in the index information. The chunk request message includes the node information of the user node, the content ID of the desired content, and the chunk ID of the chunk that is desired to be acquired. The content holding node that has received the chunk request message transmits (uploads) the chunk corresponding to the chunk ID included in the chunk request message to the user node. On the other hand, when there is no content holding node that stores a desired chunk, the user node cannot acquire the index information of the content holding node. In this case, the user node acquires a chunk from the center server.

  Alternatively, the root node transmits a chunk transmission request message to the content holding node indicated by the IP address or the like included in the index information. The chunk transmission request message includes node information of a transmission source of the chunk transmission request message. The content holding node that has received the chunk transmission request message starts transmission (upload) of content data to the user node indicated by the node information included in the received chunk transmission request message. As a result, the user node can acquire content data from the content holding node.

  Then, when the user node acquires the chunk from the content holding node and stores it, the user node discloses the chunk. Chunk disclosure refers to notifying a root node that a user node has saved a chunk as a content holding node. By publishing the chunk, other node devices can acquire the published chunk from the published content holding node. Specifically, the user node that stores the chunk transmits a publish message. The publish message includes the chunk ID of the chunk and the node information of the user node storing the chunk. The publish message is sent toward the root node. As a result, the publish message arrives at the root node by DHT routing using the chunk ID as a key, like the search message. The root node stores index information including a set of node information and chunk ID included in the received publish message in the index information cache. Thus, the user node becomes a new content holding node for storing the chunk. As described above, in the present embodiment, the control message includes the node information of the transmission source of the control message.

[How to relay content data]
Next, a content data relay method to the participating node device B will be described. The participating node device A and the participating node device C of the present embodiment acquire content by the content acquisition operation described above. On the other hand, when the participating node device B acquires content, the participating node device B transmits a search message to the first node device. The first node device that has received the search message transfers the search message based on the DHT routing table stored in the first node device. The first node device registers the node ID of the participating node device B in association with the IP address and port number of the participating node device B in the socket table.

Then, the first node device rewrites the IP address included in the node information of the participating node device B that is the transmission source included in the search message with the IP address of the first node device. That is, the first node device transmits the search message with the IP address of the source node device included in the search message as the IP address of the first node. Then, the root node that has received the search message acquires one or more index information corresponding to the chunk IDs included in the search message from the index information cache. The acquired index information is returned to the first node device set as the transmission source of the search message. The first node device that has received the returned index information first determines whether the node ID indicating the destination of the received index information matches the node ID of the first node device. If they do not match, it is determined whether or not the node ID indicating the destination of the received index information is registered in the socket table. If registered in the socket table, the received index information is determined to be index information addressed to the participating node apparatus B. Then, the first node device relays the index information to the participating node device B registered in the socket table. This is similar to relaying control messages.

Then, the participating node device B that acquired the index information acquires (downloads) the chunk based on the index information. At the time of downloading, the first node device relays the same as the control message and the search message. When the participating node device B acquires a chunk based on the index information, the participating node device B transmits a chunk request message to the first node device. The first node device that has received the chunk request message transfers the chunk request message to the content holding node that is the transmission destination of the chunk request message. The first node device registers the node ID of the participating node device B in association with the IP address and port number of the participating node device B in the socket table. Then, the first node device rewrites the IP address included in the node information of the participating node device B that is the transmission source included in the chunk request message with the IP address of the first node device. That is, the first node device transmits the chunk request message with the IP address of the transmission source node device included in the chunk request message as the IP address of the first node. Then, the content holding node that has received the chunk request message returns a chunk corresponding to the chunk ID included therein to the first node device set as the transmission source of the chunk request message. The first node device that has received the returned chunk first determines whether the node ID indicating the destination of the received chunk matches the node ID of the first node device. If they do not match, it is determined whether or not the node ID indicating the destination of the received chunk is registered in the socket table. If it is registered in the socket table, it is determined that the received chunk is a chunk addressed to the participating node apparatus B. Then, the first node device relays the chunk to the participating node device B indicated by the IP address registered in the socket table. This is similar to relaying control messages and search messages. The same relay is performed for the chunk transmission request message. Note that the control message relayed in this embodiment includes the search message, index information, chunk request message, chunk transmission request message, and chunk described above.

[Electric configuration of node device and first node device]
Next, the electrical configuration of the node device and the first node device will be described with reference to FIG. FIG. 4 is a block diagram illustrating an electrical configuration of the node device and the first node device according to the present embodiment. As illustrated in FIG. 4, the node device and the first node device according to the present embodiment include a CPU 1 that controls the node device and the first node device. An HDD 2, a RAM 3, a decoder unit 4, and a communication unit 9 are electrically connected to the CPU 1. The storage means such as the HDD 2 and the RAM 3 and the CPU 1 constitute a computer of the node device and the first node device. The CPU 1, HDD 2, RAM 3, decoder unit 4, and communication unit 9 are connected to each other via a bus. As the node device and the first node device, a personal computer, an STB (Set Top Box), or the like can be applied.

  The HDD 2 includes a program storage area 21 and a routing table storage area 25. The program storage area 21 includes a node device main operation processing program 22, a participation message processing program storage area 23, and a relay processing program storage area 24.

  The node device main operation processing program storage area 22 stores a node device main operation processing program. The node device main operation processing program is a program that causes the node device to execute main operation processing.

  The participation message processing program storage area 23 stores a participation message processing program. The participation message processing program is a program that causes the node device to execute participation processing.

  The relay processing program storage area 24 stores a relay processing program. The relay processing program is a program that causes the node device to execute a relay processing operation. The node device main operation processing program, the participation processing program, and the relay processing program may be downloaded from a predetermined server on the network NW, for example, or may be recorded on a recording medium such as a CD-ROM. It may be recorded and read via a drive of the recording medium.

  The routing table storage area 25 stores a DHT routing table and version information of the DHT routing table. In this embodiment, the overlay network OL is constructed by node devices that can communicate with IPv4. Therefore, version information indicating IPv4 is stored in the routing table storage area 25 together with the DHT routing table. The routing table storage area 25 of this embodiment is an example of a first storage unit of the present invention.

  The RAM 3 includes a content data temporary storage area 31, a relay message temporary storage area 32, a socket table temporary storage area 33, a first node device information temporary storage area 34, a version information temporary storage area 35, and an address information temporary storage area 36. .

  The content data temporary storage area 31 temporarily stores content transmitted and received by the overlay network OL. Further, the content data temporary storage area 31 temporarily stores the content relayed to the participating node device B. The content data temporary storage area 31 of the present embodiment is an example of a third storage unit.

  The relay message temporary storage area 32 temporarily stores a control message relayed to the participating node apparatus B or a control message relayed from the participating node apparatus B to another node apparatus.

  The socket table temporary storage area 33 temporarily stores a socket table. When the first node device is determined among the plurality of node devices connected to the information communication system S, the socket table is temporarily stored in the socket table temporary storage area 33.

  The first node device information temporary storage area 34 temporarily stores node information of the first node device. The node information of the first node device transmitted from the contact node is temporarily stored in the first node device information temporary storage area 34. The first node information temporary storage area 34 of this embodiment is an example of the second storage means of the present invention.

  The version information temporary storage area 35 temporarily stores version information. The version information is a protocol with which the node device can communicate. When the node device can communicate with both IPv4 and IPv6, version information indicating IPv4 and IPv6 is temporarily stored in the version information temporary storage area 35. When the node device can communicate only with IPv4, version information indicating IPv4 is stored in the version information temporary storage area 35. When the node device can communicate only with IPv6, version information indicating IPv6 is stored in the version information temporary storage area 35. The version information of this embodiment may be set in advance in each node device, or may be acquired by directly connecting from another device. Further, the version information may be acquired from another device via the network NW.

  The address information temporary storage area 36 stores the IP address of the contact node. For example, when a P2P software program is downloaded by a node device, the IP address of the contact node is acquired. The acquired IP address of the contact node is temporarily stored in the address information temporary storage area 36.

  The communication unit 9 controls communication of information with a node device or an external device through the network NW.

  The node device and the first node device perform a reception process for receiving content transmitted in response to a request via the communication unit 9. The contents of this embodiment are transmitted in packets. Each packet is received through the communication unit 9 and temporarily stored in the RAM 3. The content temporarily stored in this manner is read from the RAM 3 and reproduced and output through the decoder unit 4, the video processing unit 5, the audio processing unit 7, the display 6, and the speaker 8. Alternatively, the content stored in the RAM 3 may be read from the RAM 3 and stored in the HDD 2. Alternatively, the content may be stored directly in the HDD 2 without going through the RAM 3. Thereafter, the content is read from the HDD 2 in accordance with an operation instruction from the user. The read content is reproduced and output through the decoder unit 4, the video processing unit 5, the audio processing unit 7, the display 6, and the speaker 8. Thereby, the user can view the content.

[Electrical configuration of contact node]
Next, the electrical configuration of the contact node will be described with reference to FIG. FIG. 5 is a block diagram showing an electrical configuration of the contact node of the present embodiment. Basically, the electrical configuration of the contact node is the same as that of the node device and the first node device. Therefore, only different points will be described.

  The contact node HDD 2 includes a program storage area 21 and a routing table storage area 25 in the same manner as the node apparatus and the first node apparatus. Unlike the node device and the first node device, the contact node program storage region 21 includes a contact node main operation processing program storage region 26. The contact node main operation processing program storage area 26 stores a contact node main operation processing program. The contact node main operation processing program is a program for causing the contact node device to execute a main operation. Note that the contact node main operation processing program may be downloaded from a predetermined server on the network NW, for example, or recorded on a recording medium such as a CD-ROM via a drive of the recording medium. May be read.

  The contact node RAM 3 includes a participation message temporary storage area 37 and a first node information temporary storage area 34. The participation message temporary storage area 37 temporarily stores a participation message. The participation message transmitted by the participating node device is received by the contact node. The received participation message is temporarily stored in the participation message temporary storage area 37. The first node device information temporary storage area 34 of the contact node temporarily stores the node information transmitted from the participating node device as the node information of the first node device. Specifically, when the version information included in the participation message received by the contact node device indicates that communication is possible in both IPv4 and IPv6, the node information of the participating node device that transmitted the participation message is the first information. The node information of one node device is temporarily stored in the first node device information temporary storage area 34. The first node information temporary storage area 34 of this embodiment is an example of the second storage means of the present invention.

[Description of contact node main operation processing]
The operation and action of the contact node of the present embodiment having the above-described configuration will be described with reference to the accompanying drawings. FIG. 6 is a flowchart showing a processing procedure of contact node main operation processing in the contact node. The contact node main operation process of the contact node device is performed when an external power source such as a commercial power source and the node device are connected via a power source or an outlet and determined as the contact node device. The processing shown below is processed by the CPU 1.

  In step S101, it is determined whether or not a participation message has been received from the participating node device. If it is determined that the participation message has been received (step S101: YES), step S102 is executed. If it is not determined that the participation message has been received (step S101: NO), step S107 is executed. When the participation message is received, the received participation message is temporarily stored in the participation message information temporary storage area 37. The computer of this embodiment and step S101 are an example of the receiving means of this invention. Moreover, step S101 of this embodiment is an example of the receiving step of this invention.

  In step S102, it is determined whether there is information that matches the version information of the routing table in the version information of the participating node devices. Specifically, the version information stored in the routing table storage area 25 is compared with the version information included in the participation message. The participation message version information is temporarily stored in the participation message temporary storage area 37. As a result of the comparison, if it is determined that there is information that matches the version information of the routing table in the version information of the participating node devices (step S102: YES), step S103 is executed. If it is not determined that there is information that matches the version information in the routing table among the version information of the participating node devices (step S102: NO), step S104 is executed. The computer of this embodiment and step S102 are examples of the determination means of this invention. Moreover, step S102 of this embodiment is an example of the determination step of the present invention.

  In step S103, a participation process is executed. Specifically, the DHT routing table stored in the routing table storage area 25 is transmitted to the participating node devices. The computer of this embodiment and step S103 are an example of the transmission means of this invention. Moreover, step S103 of this embodiment is an example of the transmission step of this invention.

  In step S104, the node information of the first node device temporarily stored in the first node device information temporary storage area 34 is transmitted to the participating node devices. The computer of this embodiment and step S104 are an example of the transmission means of this invention. Moreover, step S103 of this embodiment is an example of the transmission step of this invention.

  In step S105, it is determined whether or not the participating node device can communicate with both IPv4 and IPv6. Whether or not the participating node device can communicate with both IPv4 and IPv6 is determined based on the version information stored in the participation message information temporary storage area 32. When the version information indicates IPv4 and IPv6, it is determined that the participating node device can communicate with both IPv4 and IPv6. When it is determined that the participating node device can communicate with both IPv4 and IPv6 (step S105: YES), step S106 is executed. If it is not determined that the participating node device can communicate with both IPv4 and IPv6 (step S105: NO), step S107 is executed.

  In step S106, the node information included in the participation message stored in the participation message information temporary storage area 37 is temporarily stored in the first node apparatus information temporary storage area 34 as the node information of the first node apparatus.

  In step S107, it is determined whether or not the contact node is powered off. When it is determined that the power is turned off (step S107: YES), the contact node main operation process of the contact node is ended. If it is not determined that the power has been turned off (step S107: NO), step S101 is executed again.

[Description of node device main operation processing]
With reference to FIG. 7, operation | movement and an effect | action of the node apparatus of this embodiment and a 1st node apparatus are demonstrated with reference to an accompanying drawing. FIG. 7 is a flowchart showing a processing procedure of node device main operation processing in the node device and the first node device. The node device main operation processing of the node device and the first node device is performed by the CPU 1 executing the installed P2P software program by connecting the external power source such as a commercial power source to the node device and the first node device via a power source or an outlet. It is carried out by being done.

  In step S201, it is determined whether a participation message is transmitted. When it is determined that the participation message is transmitted (step S201: YES), step S202 is executed. If it is not determined that the participation message is transmitted (step S201: NO), step S203 is executed.

  In step S202, a participation message process is executed. Details of the participation message processing will be described later.

  In step S203, it is determined whether a control message is transmitted. When it is determined that the control message is transmitted (step S203: YES), step S204 is executed. If it is not determined that the control message is transmitted (step S203: NO), step S207 is executed.

  In step S204, it is determined whether or not the node device that executes step S204 participates in the overlay network OL. Whether or not it participates in the overlay network is determined, for example, by whether or not the DHT routing table is stored in the routing table storage area 25. If the DHT routing table is stored in the routing table storage area 25, it is determined that the mobile terminal is participating in the overlay network OL. When the DHT routing table is not stored in the routing table storage area 25, it is determined that the DHT does not participate in the overlay network OL. When it is determined that the node device that executes Step S204 participates in the overlay network OL (Step S204: YES), Step S205 is executed. When it is not determined that the node device that executes Step S204 participates in the overlay network OL (Step S204: NO), Step S206 is executed.

  In step S205, a control message is transmitted to the node device registered in the DHT routing table.

  In step S206, a control message is transmitted to the first node device. Specifically, the control message is transmitted to the first node device based on the IP address included in the node information stored in the first node device information temporary storage area 34.

  In step S207, it is determined whether a control message has been received. The control message received in step S207 includes a chunk request message. If it is determined that the control message has been received (step S207: YES), step S208 is executed. If it is not determined that the control message has been received (step S207: NO), step S215 is executed. Step S207 for receiving a control message including a chunk request message and the computer of this embodiment are an example of a request receiving means of the present invention.

  In step S208, it is determined whether or not the node device that executes step S208 is the first node device. Specifically, based on the version information stored in the version information temporary storage area 35, it is determined whether or not the node device that executes Step S208 is the first node device. When the version information temporarily stored in the version information temporary storage area 35 indicates that communication is possible with both IPv4 and IPv6, it is determined to be the first node device. When it is determined that the node device that executes Step S208 is the first node device (Step S208: YES), Step S209 is executed. If it is not determined that the node device that executes step S208 is the first node device (step S208: NO), step S214 is executed.

In step S209, it is determined whether or not the transmission source of the control message received in step S207 is a node device that needs to be relayed. Specifically, it is determined whether or not the node ID of the node information in the received control message is registered in the socket table. When it is determined that it is registered in the socket table, it is determined that the node device needs to be relayed. On the other hand, if it is not determined that it is registered in the socket table, it is determined that the node device does not require relay. When it is determined that the transmission source of the control message received in step S207 is a node device that requires relay (step S209: YES), step S210 is executed. When it is not determined that the transmission source of the control message received in step S207 is a node device that needs to be relayed (step S209: NO), step S211 is executed.

  In step S210, relay processing is executed. Specifically, the IP address of the node information included in the control message received in step S207 is rewritten with the IP address of the node device that executes step S210. Then, the node ID of the node device that is the transmission source of the control message and the IP address and port number of the transmission source of the control message are associated and registered in the socket table.

In step S211, it is determined whether or not the destination of the control message received in step S207 is a node device that needs to be relayed. Whether the node device needs to be relayed is determined based on the node ID included in the control message. When the node ID included in the participation message is stored in the socket table temporary storage area 33, it is determined that the control message received in step S207 is a message addressed to the node device that needs to be relayed. If it is determined that the destination of the control message received in step S207 is a node device that needs to be relayed (step S211: YES), step S212 is executed. If it is not determined that the destination of the control message received in step S207 is a node device that needs to be relayed (step S211: NO), step S213 is executed. If it is determined that the destination of the control message received in step S207 is a node device that needs to be relayed, the control message received in step S207 is temporarily stored in the relay message temporary storage area 32. If the control message received in step S207 is a chunk, the chunk received in step S207 may be temporarily stored in the content data temporary storage area 31. The computer of this embodiment and step S211 are an example of the 2nd acquisition means of this invention.

  In step S212, the control message received in step S207 is relayed to the node device that needs to be relayed. Specifically, in step S211, it is determined whether a node ID that matches the node ID added to the control message received in step S207 is registered among the node IDs registered in the socket table. . If it is determined that a matching node ID is registered, in step S212, an IP address corresponding to the node ID determined to match is acquired from the node information registered in the socket table. Then, the control message is relayed to the node device indicated by the acquired IP address. The computer of this embodiment and step S212 are an example of the relay means of this invention.

  In step S213, the control message is transmitted to the node device registered in the DHT routing table.

In step S214, processing corresponding to the control message received in step S207 is executed. For example, if the destination of the control message is not the node device that received the control message in step S207, the control message is transferred. If the destination of the control message is the node device that has received the control message in step S207, processing corresponding to the control message is executed.

  In step S215, it is determined whether or not the power of the node device or the first node device has been turned off, or whether or not the leaving process has been executed. The leaving process means that the node device or the first node device leaves the overlay network OL. Specifically, the leaving process is a case where activation of the P2P software program installed in the node device or the first node device is stopped. When it is determined that the power is turned off or the disconnection process is executed (step S215: YES), the main operation process of the node device and the first node device is ended. When it is not determined that the power is turned off or the separation process is executed (step S215: NO), step S201 is executed again.

[Description of participation message processing]
Next, the processing procedure of the participation message processing operation of this embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the participation message processing operation of the present embodiment. First, in step S301, connection to a contact node is executed. Based on the IP address stored in the address information temporary storage area 36, connection to the contact node is executed.

  In step S302, it is determined whether or not a DHT routing table has been received from the contact node. If it is determined that the DHT routing table has been received (step S302: YES), step S303 is executed. If it is not determined that the DHT routing table has been received (step S302: NO), step S304 is executed.

  In step S303, a process for joining the overlay network OL is executed. Specifically, the DHT routing table received in step S302 is stored in the routing table storage area 25. Then, communication is possible using the overlay network OL. If a part of the DHT routing table is received in step S302, the remaining DHT routing tables are acquired from other node devices based on the received part of the DHT routing table in step S303. Also good.

  In step S304, it is determined whether node information of the first node device has been received. If it is determined that the node information of the first node device has been received (step S304: YES), step S305 is executed. If it is not determined that the node information of the first node device has been received (step S304: NO), step S302 is executed. When node information of the first node device is received in step S304, the received node information is temporarily stored in the first node device information temporary storage area 34. The computer of this embodiment and step S304 are an example of a first acquisition unit of the present invention.

In step S305, a session with the first node device is generated. Specifically, a session with the first node device is generated based on the node information received in step S304. The computer of this embodiment and step S305 are an example of the 1st production | generation means of this invention.

  Hereinafter, modifications of the present embodiment will be described. As a modification, in the present embodiment, a node device that needs to relay does not necessarily have to transmit a publish message. FIG. 9 is a flowchart of a publishing process according to a modification of the present embodiment. The publishing process is a process periodically executed by a node device that needs to be relayed in this embodiment. The publishing process is started every predetermined time by a timer provided in the node device. The publishing process is started when content is stored in the content data temporary storage area 31 by the node device.

  In step S501, a content ID that needs to be published among the content stored in the content data temporary storage area 31 is determined. Then, a search message for the determined content ID is transmitted. The content ID that needs to be published is, for example, content that is close to the release start time. The near release start time indicates that the time difference or date difference between the current time and the content release start time is within a predetermined period. The content ID that needs to be published is a content in which content is newly stored in the content data temporary storage area 31. In step S501, the timer operation is started by a timer provided in the node device. The computer of this embodiment and step S501 are an example of the search means of this invention.

  In step S502, it is determined whether an index cache corresponding to the search message transmitted in step S501 has been received. If it is determined that the index cache has been received (step S502: YES), the publishing process is terminated. If it is not determined that the index cache has been received (step S502: NO), step S503 is executed.

  In step S503, it is determined whether or not a predetermined time has elapsed since the timing operation was started in step S501. If it is determined that the predetermined time has elapsed (step S503: YES), step S504 is executed. If it is not determined that the predetermined time has elapsed (step S503: NO), step S502 is executed.

  In step S504, a publish message including the content ID determined in step S501 is transmitted. The computer of this embodiment and step S504 are an example of the disclosure means of the present invention.

  In this modification, it is necessary to relay content to a node device that requires relay. In order to communicate content stably, it is better for node devices that require relaying to refrain from uploading data as much as possible. When a node device requiring relaying publishes content, the content index cache is searched by the overlay network OL. Since the publish message is transmitted when the search cannot be performed, it is possible to refrain as much as possible so that the node device that needs to relay can upload the content. As a result, occurrence of relay processing can be prevented and communication can be performed efficiently. In this modification, the publish message is transmitted when the index cache cannot be searched or received. However, the present invention is not limited to this. An index cache may be retrieved or received. The publish message may be transmitted when the number of content holding nodes included in the retrieved or received index cache is a predetermined number or less.

  In this embodiment, the peer-to-peer communication system using the DHT routing table is applied to the overlay network OL. However, the present invention is not limited to this. The present invention may be applied to other peer-to-peer communication systems or systems using overlay networks. For example, the present invention may be applied to a communication system using a routing table other than DHT or a peer-to-peer communication system. An example of a peer-to-peer communication system that does not use DHT is a hybrid peer-to-peer communication system. The present invention may be applied to a hybrid peer-to-peer communication system or a pure peer-to-peer communication system.

  In the present embodiment, the overlay network OL is configured by a node device that can communicate with IPv4, but is not limited to this. For example, the overlay network OL may be configured by a node device that can communicate with IPv6. In this case, a session is generated between the node device that can communicate only with IPv4 and the first node device. Further, a DHT routing table in which node information of node devices capable of communicating with IPv6 is registered is generated and stored in the routing table storage area.

1 CPU
2 HDD
3 RAM
4 Decoder unit 5 Video processing unit 6 Display 7 Audio processing unit 8 Speaker 9 Communication unit Tm-n Node device NW Network FW Firewall BR Broadband router S Information communication system OL Overlay network NLm Base network 21 Program storage area 22 Node device main operation processing Program storage area 23 Participation message processing program storage area 25 Routing table storage area 26 Contact node main operation processing program storage area 31 Temporary content data storage area 32 Relay message temporary storage area 33 Socket table temporary storage area 34 First node device information temporary storage Area 35 Version information temporary storage area 36 Address information temporary storage area
37 Participation Message Temporary Storage Area

Claims (7)

An information communication system for transmitting and receiving a plurality of data distributed and stored by an overlay network composed of a plurality of node devices,
The node device of any of the plurality of node devices is
Location information indicating a location on the network of node devices participating in the first overlay network, which is a first overlay network composed of at least a part of node devices communicable with IPv4, is registered. The first routing table or the second overlay network configured by at least a part of node devices communicable with IPv6, wherein the location information of the node devices participating in the second overlay network is registered. First storage means for storing any one of the second routing tables,
A second storage that stores location information indicating a location of the first node device in the network, which is one of the plurality of node devices and can communicate with both IPv4 and IPv6, which are protocols that the node device can communicate with. Means,
A participation message transmitted from a participating node device participating in the information communication system and indicating participation in the information communication system, including protocol information indicating IPv4 or IPv6 which is a protocol with which the participating node device can communicate Receiving means for receiving a participation message;
Determining means for determining whether the protocol information included in the participation message received by the receiving means matches the protocol of the routing table stored by the first storage means;
When it is determined by the determination means that they match, at least a part of the routing table determined to match is transmitted to the participating node devices,
A transmitting means for transmitting the location information of the first node device stored in the second storage means to the participating node device when it is not determined to match by the determining means;
An information communication system comprising: The participating node device is:
First acquisition means for acquiring the location information of the first node device transmitted by the transmission means;
First generation means for generating a session using a protocol communicable with the participating node apparatus to the first node apparatus indicated by the location information acquired by the first acquisition means;
With
The first node device is
Request receiving means for receiving a predetermined request for the data from the participating node device for which a session has been generated by the first generating means;
Second acquisition means for acquiring the data requested by the request reception means from any of the node devices connected to the overlay network;
Relay means for relaying the data acquired by the second acquisition means to the participating node device;
The information communication system according to claim 1, further comprising: The participating node device is:
Third storage means for storing the data;
Publishing means for publishing data stored in the third storage means on the overlay network;
Search means for searching the data published by the publication means using the overlay network before the data is published by the publication means;
With
The information communication system according to claim 2, wherein when the data to be disclosed is not searched by the search means, the release means releases the data.   When the protocol information included in the participation message received by the receiving unit indicates that communication is possible in both IPv4 and IPv6, the second storage unit sets the participating node device as the first node device. The information communication system according to any one of claims 1 to 3, wherein the location information of the participating node devices is stored. The node device of any of the plurality of node devices included in an information communication system that transmits and receives a plurality of data stored in a distributed manner by an overlay network composed of a plurality of node devices,
Location information indicating a location on the network of node devices participating in the first overlay network, which is a first overlay network composed of at least a part of node devices communicable with IPv4, is registered. The first routing table or the second overlay network configured by at least a part of node devices communicable with IPv6, wherein the location information of the node devices participating in the second overlay network is registered. First storage means for storing any one of the second routing tables,
A second storage that stores location information indicating a location of the first node device in the network, which is one of the plurality of node devices and can communicate with both IPv4 and IPv6, which are protocols that the node device can communicate with. Means,
A participation message transmitted from a participating node device participating in the information communication system and indicating participation in the information communication system, including protocol information indicating IPv4 or IPv6 which is a protocol with which the participating node device can communicate Receiving means for receiving a participation message;
Determining means for determining whether the protocol information included in the participation message received by the receiving means matches the protocol of the routing table stored by the first storage means;
When it is determined by the determination means that they match, at least a part of the routing table determined to match is transmitted to the participating node devices,
A transmitting means for transmitting the location information of the first node device stored in the second storage means to the participating node device when it is not determined to match by the determining means;
A node device comprising: An information communication method for transmitting and receiving a plurality of data distributed and stored by an overlay network composed of a plurality of node devices and executed by any one of the plurality of node devices,
A participation message transmitted from a participating node device participating in the information communication system and indicating participation in the information communication system, including protocol information indicating IPv4 or IPv6 which is a protocol with which the participating node device can communicate A receiving step for receiving a participation message;
Location information indicating a location on the network of node devices participating in the first overlay network, which is a first overlay network composed of at least a part of node devices communicable with IPv4, is registered. The first routing table or the second overlay network configured by at least a part of node devices communicable with IPv6, wherein the location information of the node devices participating in the second overlay network is registered. It is determined whether the protocol of the routing table stored by the first storage unit that stores one of the routing tables stored in the second routing table matches the protocol information included in the participation message received by the receiving step Do And a constant step,
When it is determined to match by the determination step, at least a part of the routing table determined to match is transmitted to the participating node device,
In the network of the first node device that can communicate with both IPv4 and IPv6, which is one of the plurality of node devices and the node device can communicate with when it is not determined to match in the determination step A transmitting step of transmitting the location information of the first node device stored in second storage means for storing location information indicating the location to the participating node device;
An information communication method including: By transmitting and receiving a plurality of data stored in a distributed manner by an overlay network composed of a plurality of node devices, the computer of the node device of any of the plurality of node devices,
A participation message transmitted from a participating node device participating in the information communication system and indicating participation in the information communication system, including protocol information indicating IPv4 or IPv6 which is a protocol with which the participating node device can communicate A receiving step for receiving a participation message;
Location information indicating a location on the network of node devices participating in the first overlay network, which is a first overlay network composed of at least a part of node devices communicable with IPv4, is registered. The first routing table or the second overlay network configured by at least a part of node devices communicable with IPv6, wherein the location information of the node devices participating in the second overlay network is registered. It is determined whether the protocol of the routing table stored by the first storage unit that stores one of the routing tables stored in the second routing table matches the protocol information included in the participation message received by the receiving step Do And a constant step,
When it is determined to match by the determination step, at least a part of the routing table determined to match is transmitted to the participating node device,
In the network of the first node device that can communicate with both IPv4 and IPv6, which is one of the plurality of node devices and the node device can communicate with when it is not determined to match in the determination step A transmitting step of transmitting the location information of the first node device stored in second storage means for storing location information indicating the location to the participating node device;
A program characterized by having executed.