JP2006101277A - Information communications system, node apparatus, and overlay network forming method or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information communications system capable of collecting information with a higher efficiency from the whole system, without using a management server and to provide a node apparatus, an overlay network forming method, and a log collection processing program, a representative selection processing program, a participation request processing program, and a participation discrimination processing program or the like. <P>SOLUTION: In the information communications system wherein all or parts of a plurality of node apparatuses among a plurality of node apparatuses physically interconnected via a communication means take part in an overlay network to form the overlay network, parts of a plurality of the node apparatuses are selected as representatives from a plurality of the node apparatuses taking part in the overlay network, and a high-order overlay network is formed by the participation of a plurality of the node apparatuses selected as the representatives. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a peer-to-peer (P2P) type in which an overlay network is formed by participation of all or part of a plurality of node devices physically connected to each other via communication means. The present invention relates to technical fields such as information communication systems.

  In recent years, peer-to-peer information communication systems have begun to attract attention in communication networks such as the Internet. This information communication system differs from a client / server type information communication system in that, for example, content data is transmitted and received between node devices as clients.

For example, as this type of information communication system, Patent Document 1 discloses a stream data distribution and delivery system, in which each node device has topology information for recognizing a network connection relationship. Each node device is connected to an upstream (upper layer) node device recognized by the topology information, and receives stream data transmitted from the upstream node device.
JP 2003-169089 A

  By the way, in the peer-to-peer type information communication system in which all the node devices participating in the system have equal functions, the network resources in the system can be used more efficiently than the client / server type information communication system, Each node device knows only the information of its neighboring node devices, and because the entire system operates autonomously as an aggregate, it is necessary to manage the entire system such as billing and authentication. It is unsuitable and, in reality, it is an illegal system under the Copyright Act that does not have such a management process, or a client / server model is used in the process of billing / authentication by building a separate management server. It was either used together.

  The present invention has been made in view of the above points and the like. An information communication system, a node device, and an overlay network that can collect information more efficiently from the entire system without using a management server. It is an object to provide a method, a log collection processing program, a representative selection processing program, a participation request processing program, a participation determination processing program, and the like.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that an overlay network is formed by participation of all or some of a plurality of node devices physically connected to each other via communication means. In the formed information communication system, some of the plurality of node devices selected from among the plurality of node devices participating in the overlay network are selected as representatives, and the plurality of nodes selected as the representatives A higher-level overlay network is formed by the participation of devices.

  According to the first aspect of the present invention, an upper overlay network is formed by the participation of the plurality of node devices selected as representatives from the plurality of node devices participating in the overlay network. The information such as logs can be collected more efficiently by a plurality of node devices selected as representatives without using the management server.

  According to a second aspect of the present invention, in the information communication system according to the first aspect, the overlay network is formed in N layers (N is a natural number of 2 or more), and the Nth layer overlay network is the Nth layer. It is formed by the participation of a part of a plurality of node devices selected as representatives from among the plurality of node devices participating in the -1 layer overlay network.

  According to a third aspect of the present invention, in the information communication system according to the first or second aspect, each of the node devices participating in the overlay network of any one of the other is participating in the overlay network. It is possible to directly communicate with only some of the node devices among all the node devices.

  Invention of Claim 4 is said representative node apparatus contained in the information communication system of Claim 3, Comprising: The log collection means which collects a log from the said other node apparatus which can communicate directly, Collection log transmission means for transmitting the collected log as a collection log to another representative node device, and collection for acquiring the collection log collected in the other representative node device from the other representative node device Log acquisition means.

  According to the invention described in claim 4, the representative node device collects logs from neighboring node devices that can communicate more directly, and exchanges the collected logs with other collected representative node devices. The collection log can be shared between the representative node devices, the log can be collected more efficiently from the entire system without using the management server, and billing information can be generated based on this.

  The invention according to claim 5 is the node device included in the information communication system according to claim 3, wherein the node device is a predetermined one of the other node devices capable of direct communication and a plurality of node devices including itself. Representative candidate selecting means for selecting at least one node device that satisfies the representative candidate selection condition as a representative candidate, and a representative candidate indicating at least one representative candidate node device selected in the other node device capable of direct communication The information is indicated by representative candidate information acquisition means for acquiring information from the other node devices that can communicate directly, the representative candidate node device selected by the representative candidate selection means, and the acquired representative candidate information. A representative selection unit that selects at least one node device that satisfies a predetermined representative selection condition from among the representative candidate node devices; As a representative for the node device selected as a representative by the representative selection means when it is determined that the node device selected as Transmitting means for transmitting representative selection information indicating selection.

  According to the fifth aspect of the invention, it is possible to accurately select a representative node device that collects information such as logs from the entire system.

  According to a sixth aspect of the present invention, in the node device according to the fifth aspect, the overlay corresponding to the upper layer of the overlay network in which the self participates when the determination unit determines that the node device is self. Participation request means for making a participation request to another node device participating in the network, and participation notification from the other node device in response to the participation request, participation in the overlay network corresponding to the upper layer And a participation means for performing a participation process.

  According to the sixth aspect of the present invention, the node device selected as a representative can efficiently participate in the overlay network corresponding to the upper layer.

  The invention according to claim 7 is a node device that receives the representative selection information transmitted from the node device according to claim 5, and when the representative selection information is received, A participation request means for making a participation request to another node device participating in the overlay network corresponding to an upper layer of the overlay network, and an acceptance notification for the participation request from the other node device Comprises participation means for performing a participation process for participating in the overlay network corresponding to the upper layer.

  According to the seventh aspect of the present invention, the node device selected as a representative can efficiently participate in the overlay network corresponding to the upper layer.

  The invention according to claim 8 is a node device that receives a participation request from the node device according to claim 6 or 7, and when the participation request is received, whether or not a predetermined participation condition is satisfied. A participation condition determining means for determining; and an acceptance notifying means for notifying the acceptance of the participation request to the node device that has made the participation request when the participation condition is satisfied.

  According to the invention described in claim 8, it is possible to regulate the number of representative node devices participating in the overlay network corresponding to the upper layer.

  The invention according to claim 9 is an information communication system in which an overlay network is formed by participation of all or some of a plurality of node devices physically connected to each other via a communication means. A method for forming a network, comprising: selecting a plurality of node devices as a representative from among the plurality of node devices participating in the overlay network; and selecting the plurality of node devices selected as the representative Forming a higher-level overlay network by participation.

  According to a tenth aspect of the present invention, there is provided a log collecting means for collecting a log from the other node device that can communicate directly with a computer included in the representative node device included in the information communication system according to the third aspect. A collection log transmitting means for transmitting the collected log as a collection log to another representative node device; and a collection log collected by the other representative node device is acquired from the other representative node device. It is made to function as a collection log acquisition means to perform.

  According to an eleventh aspect of the present invention, a computer included in the node device included in the information communication system according to the third aspect can be used as the other node device capable of direct communication and a plurality of node devices including itself. A representative candidate selecting means for selecting at least one node device satisfying a predetermined representative candidate selection condition as a representative candidate, a representative indicating at least one representative candidate node device selected in the other node device capable of direct communication Candidate information is indicated by representative candidate information acquisition means for acquiring from the other node devices that can communicate directly, representative candidate node device selected by the representative candidate selection means, and the acquired representative candidate information. Representative selection that selects at least one node device that satisfies a predetermined representative selection condition from among representative candidate node devices. A determination means for determining whether or not the node device selected as the representative is self; and if it is determined that the node device is not self, the node device selected as a representative by the representative selection means On the other hand, it is made to function as a transmission means for transmitting representative selection information indicating that it has been selected as a representative.

  According to a twelfth aspect of the present invention, when the representative selection information is received by a computer included in the node device that receives the representative selection information transmitted from the node device according to the seventh aspect, the self participates. There is a participation request means for making a participation request to another node device participating in the overlay network corresponding to an upper layer of the overlay network, and there is an acceptance notification for the participation request from the other node device. In such a case, it functions as a participation means for performing a participation process for participating in the overlay network corresponding to the upper layer.

  According to a thirteenth aspect of the present invention, a computer included in a node device that receives a participation request from the node device according to the eighth aspect determines whether or not a predetermined participation condition is satisfied when the participation request is received. A participation condition determination unit for determining, and when the participation condition is satisfied, the node device that functions as the participation request functions as an acceptance notification unit that performs an acceptance notification on the participation request.

  A fourteenth aspect of the invention is characterized in that the program according to any one of the tenth to thirteenth aspects is recorded so as to be readable by a computer.

  According to the present invention, since a higher-level overlay network is formed by the participation of the plurality of node devices selected as representatives from the plurality of node devices participating in the overlay network, the selection is made as the representative. By using the plurality of node devices, information such as logs can be collected more efficiently.

  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 content distribution system.

[1. Content distribution system configuration]
First, with reference to FIG. 1, a schematic configuration and the like of the content distribution system in the present embodiment will be described.

  FIG. 1 is a diagram illustrating a schematic configuration example of a content distribution system according to the present embodiment.

  A content distribution system S according to the present embodiment includes a communication line (for example, a telephone line or an optical cable) 50, IX (Internet eXchange) 51, 52, ISP (Internet Service Provider) 53, 54, 55, a router (not shown). ) And the like, and a plurality of node devices 1 to 23 physically connected to each other via a communication means (for example, the Internet), as shown in FIG. Has been built.

  The content distribution system S in the present embodiment is a pure P2P type network system that does not require a server that manages the entire system S. Each of the node devices 1 to 23 is assigned a unique manufacturing number and an IP (Internet Protocol) address, and does not overlap among a plurality of node devices. In the following description, when any one of the node devices 1 to 23 is indicated, it is simply referred to as “node device” for convenience.

  Assuming such a physical network 100, as shown in FIG. 1, overlay networks 101, 102, and 103 having a plurality of layers thereon (first, second, and third in the example of FIG. 1) are provided. Are all three layers, but more than this may be formed. These overlay networks 101 to 103 are virtual networks formed by a specific algorithm, for example, an algorithm (for example, Plaxton algorithm) using a distributed hash table (hereinafter referred to as DHT (Distribute Hash Table)). It is formed by participation of all or part of the node devices 1 to 23.

  It should be noted that each node device participates in an overlay network in each layer, a method in which the participating node devices exchange information with each other, and an optimum state of the overlay network in each layer when participation and withdrawal are performed. The method of maintaining (independently maintaining) is based on, for example, the Plaxton algorithm using DHT. However, since this is known, detailed description thereof will be omitted.

  Also, as shown in FIG. 1, the higher the overlay network of the upper layer, the smaller the number of participating node devices. For example, the second-layer overlay network 102 is formed by participation of a plurality of node devices selected as representatives from a plurality of node devices participating in the first-layer overlay network 101. On the other hand, the third-layer overlay network 103 is formed by the participation of some of the node devices selected as representatives from the plurality of node devices participating in the second-layer overlay network 102. It is. Hereinafter, the node device selected as the representative is referred to as a “representative node device”.

  Further, the node ID of each node device participating in the overlay network of each layer is the IP address or serial number, and a hash function common to each overlay network of each layer (that is, for example, with the overlay network 101 of the first layer). The hash function is different from that of the second-layer overlay network 102), and is distributed in one ID space without any deviation. Thus, the node ID obtained (hashed) by the common hash function has a very low probability of having the same value if the IP address or the manufacturing number is different. In the present embodiment, a node ID is a value obtained by hashing an IP address (global IP address) with a common hash function.

  Each node device participating in the overlay network of each layer holds the DHT. In this DHT, a plurality of pieces of path information to other node devices, that is, node IDs and IP addresses of other node devices that are appropriately separated in the node ID space are registered. Such DHT is given when a node device participates in an overlay network of each layer. In the content distribution system S, since the node device 1 is frequently joined or withdrawn, whether or not the DHT needs to be updated regularly (for example, at intervals of several tens of minutes to several hours) is confirmed. The update information is transmitted to the other node device 1 via a route registered in the DHT. This makes it possible to keep the DHT up to date. Since the hash function and DHT generation method are known, detailed description thereof will be omitted.

  In addition, content (for example, movies, music, etc.) data as distribution information is distributed (stored) in all or part of the plurality of node devices 1 to 23. For example, content data of a movie with a title XXX is stored in the node device 1, while content data of movies having a title YYY is stored in the node device 3. Are distributed and stored in a plurality of node devices (however, the same content data may be distributed and stored in a plurality of node devices).

  It is necessary to search and obtain (download) content data stored in a distributed manner in this manner from any node device participating in the overlay network. There are various search methods. For example, a keyword related to content data (for example, a content name (content title), content summary information (synopsis), etc.) is used for the above node of the first layer overlay network 101. Hashing with the same hash function as when obtaining the ID (that is, the hash value of the keyword is placed in the same ID space as the hash value of the IP address) and closest to the hash value of the keyword (for example, the upper digit) The location information (for example, IP address) indicating the location of the node device that stores the content data is stored in the node device having the node ID that matches more.

  Then, the node device that searches for the content data hashes the keyword of the content data, and searches the search request information including the hash value of the keyword and its own IP address with another IP address corresponding to the IP address registered in the DHT. Sent to the node device. In the other node device that has received the search request information, it is determined whether or not its own node ID is closest to the hash value of the keyword (for example, the higher digits match more). The other node device sends the search request information to the other node device corresponding to the IP address registered in the DHT (for example, the hash value of the keyword among the node IDs registered in the DHT). It is transferred to the closest node node (for example, a node device having a node ID that matches more high-order digits). The same processing is performed in the node device that has received the search request information, and the search request information is transferred until a node device having a node ID closest to the hash value of the keyword is searched. Finally, when the node ID is closest to the hash value of the keyword, the location information of the content data (for example, IP addresses of all the node devices storing the content data, etc.) Is the root node device storing the above-described index list), the root node device transmits (replies) the location information to the node device that has transmitted the search request information. Thereby, the node device that has transmitted the search request information receives the location information of the content data, and acquires (downloads) the content data based on the location information (in other words, receives the distribution of the content data). it can.

  As described above, in the present embodiment, since the IP address (or manufacturing number) and the keyword are hashed by the hash function of the overlay network 101 of the first layer, the search and distribution of the content data as described above are performed in the first order. It is performed within the one-layer overlay network 101 and is functionally completed. That is, the first-layer overlay network 101 is mainly intended for the content data distribution function.

  On the other hand, the overlay networks 102 of the second and third layers are mainly intended to manage the entire content distribution system S. That is, in a pure P2P type network system such as the content distribution system S, all the node devices have an equivalent function, and the network resources in the system S can be used efficiently, but each node device has its own function. Since only the information of neighboring node devices is grasped, and the entire system operates autonomously as an aggregate, it is unsuitable for managing the entire system such as billing and authentication. For this reason, the representative node device selected from the first-layer overlay network 101 further forms the second-layer overlay network 102 above the first-layer overlay network 101, whereby the entire content distribution system S Can be managed efficiently. Further, the third node overlay network 103 is further formed above the second layer overlay network 102 by the representative node device selected from the second layer overlay network 102, thereby the content distribution system S. It is possible to manage the whole more efficiently.

  Here, the neighboring node device refers to a node device with which a certain node device can directly communicate. In the example of FIG. 1, node devices connected by a solid line are neighboring node devices.

  For example, when viewed from a certain node device, the number of HOPs is 1 (for example, one router in the communication path between one node device and another node device), or the node ID is close (for example, A node device whose upper-order predetermined digit matches is a neighboring node device. Each node device acquires the node ID, IP address, and the like of a neighboring node device when participating in the first layer overlay network 101.

  Then, the representative node device in the second layer overlay network 102 operates logs (for example, content data acquisition (download) history, viewing (reproduction output) history, etc.) from neighboring node devices in the first layer overlay network 101. ) Is collected. Furthermore, the representative node device in the third layer overlay network 103 plays a role of collecting operation logs from neighboring representative node devices in the second layer overlay network 102. In this way, the operation logs collected in the overlay network of each hierarchy are, for example, sucked up from the lower hierarchy to the hierarchy. Then, the collected operation log generates, for example, billing information including information on the content usage fee imposed on the user of each node device.

[2. Node device configuration]
Next, the configuration and functions of the node device will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a schematic configuration example of the node device (common to the node devices 1 to 23).

  As shown in FIG. 2, the node device includes a control unit 111 as a computer composed of a CPU having a calculation function, a working RAM, a ROM for storing various data and programs, the content data, the DHT, the program, and the like. A storage unit 112 including an HDD or the like for storing and storing (stores the content data may be a node device that is not stored), a buffer memory 113 that temporarily stores received content data, and a content Decoder 114 for decoding (data decompression, decoding, etc.) encoded video data (video information) and audio data (audio information) included in the data, and predetermined rendering for the decoded video data A video processing unit 115 that performs processing and outputs the video signal; A display unit 116 such as a CRT or a liquid crystal display for displaying an image based on the video signal output from the processing unit 115, and the decoded audio data after D (Digital) / A (Analog) conversion into an analog audio signal. An audio processing unit 117 that is amplified and output by an amplifier, a speaker 118 that outputs an audio signal output from the audio processing unit 117 as a sound wave, and encodes video data, audio data, and the like included in content data (data compression or (Encryption etc.) encoder unit 119, communication unit 120 for performing communication control of information between other node devices through communication means, and a control unit that receives an instruction from the user and receives an instruction signal according to the instruction Input unit (for example, a keyboard, a mouse, or an operation panel) ) And 121, is configured to include a control unit 111, storage unit 112, a buffer memory 113, a decoder unit 114, an encoder unit 119, and the communication unit 120 are connected to each other via a bus 122.

  Then, the CPU in the control unit 111 executes various programs stored in the storage unit 112 and the like so as to control the entire node device, and in accordance with an instruction signal from the input unit 121, Each process to be described later is performed.

[3. Operation of content distribution system]
Next, the operation of the content distribution system S will be described. In the following description, it is assumed that each node device has already participated in the first-layer overlay network 101, and at least one of the second-layer overlay network 102 and the third-layer overlay network 103 is included. Assume that two node devices participate.

(Representative selection process)
First, the representative selection process will be described with reference to FIG.

  FIG. 3 is a flowchart showing representative selection processing in the control unit 111. The representative selection process shown in FIG. 3 is performed by a representative selection processing program stored and stored in the storage unit 112 or the like being read and executed by the control unit 111, whereby the control unit 111 can It functions as a representative candidate selection means, a representative candidate information acquisition means, a representative selection means, a discrimination means, and a transmission means. The representative selection processing program may be downloaded from a predetermined server on the Internet, for example, or may be recorded on a recording medium such as a CD-ROM and read via a drive of the recording medium. It may be.

  This representative selection processing is performed at substantially the same timing in a plurality of node devices (for example, all node devices participating in the first-layer overlay network 101). When a representative selection command is executed in a node device (for example, a super node device to be described later) (for example, according to an operation instruction from an administrator who is a user of the node device), the arbitrary node device changes to a neighboring node device. The start command is transmitted to the entire node devices in the first layer overlay network 101 in a sequential manner.

  Each node device starts the representative selection process upon receiving the start command. Here, the node device 10 will be described as an example.

  When the representative selection process is started in the node device 10 in the first-layer overlay network 101, the control unit 111 acquires an IP address of a neighboring node device that can directly communicate with itself (step S1). As described above, the IP addresses of neighboring node devices are obtained when participating in the first-layer overlay network 101 and are stored in the storage unit 112.

  Next, the control unit 111 selects, as a representative candidate selection unit, at least one node device that satisfies a predetermined representative candidate selection condition from among neighboring node devices and a plurality of node devices including itself as a representative candidate (step S2). ). As the representative candidate selection conditions, for example, the node ID (which may be a serial number or IP address; the same applies hereinafter) has a maximum or minimum numerical value, or a constant or average value with a node ID numerical value (average value of node IDs). The conditions such as near. In the present embodiment, for example, one node device having a node ID having the largest node ID value is selected.

  Next, the control unit 111 communicates with each neighboring node device, and represents representative candidate information (for example, a node device having a node ID having the largest node ID) (for example, the node device having the largest node ID). The node IDs of the representative candidate node devices are exchanged (step S3). In other words, the node device 10 serves as representative candidate information acquisition means for representing the representative candidate information about the representative candidate node device selected in each of the neighboring node devices 2, 9, 11, and 18 into the neighboring node devices. Will get from. For example, in the node device 11 as well, a representative candidate node device is selected and the information is exchanged with the neighboring node devices 3, 10, 12, and 19.

  Next, the control unit 111 satisfies a predetermined representative selection condition among the representative candidate node device selected by the control unit 111 and the representative candidate node device indicated by the acquired representative candidate information. At least one node device is selected as a representative (step S4). As this representative selection condition, for example, whether or not a plurality of node devices (self and its neighboring node devices) that have selected these representative candidates are selected as representative candidates in a node device of a predetermined ratio (for example, half) or more. Such conditions are listed. For example, the node device 10 selects itself as a representative candidate, the node device 2 selects the node device 3 as a representative candidate, the node device 9 selects the node device 10 as a representative candidate, and the node device 11 selects the node device 12 as a representative candidate. Assuming that the node device 18 is selected as a representative candidate and the node device 18 has selected the node device 10 as a representative candidate, the node device 10 is selected as a representative candidate in more than half of the node devices.

  Next, the control unit 111 uses the node device selected as a representative (for example, a node device selected as a representative candidate in more than half of the plurality of node devices that have selected representative candidates) as a determination unit. It is determined whether or not the node device 10) (step S5). If it is determined that the node device 10 is not self (step S5: N), the node device selected as the representative is selected as the representative as the transmission means. Representative selection information indicating that this has been done is transmitted (step S6). If the selected node device is not a neighboring node device of the node device 10, the representative selection information is transmitted to the selected node device via the neighboring node device (passing). Become.

  On the other hand, if it is determined that the representative (node device 10) is selected as the representative (step S5: Y), the process proceeds to the participation request process shown in FIG. 4 (step S7).

  In this way, a plurality of representative node devices are determined at several locations (ranges) of the first-layer overlay network 101.

  In the above description of the representative selection process, the case where the representative node device is selected in the first layer overlay network 101 has been described, but the case where the representative node device is selected in the second layer overlay network 102 is also described. The representative selection process is performed.

(Participation request processing, participation determination processing)
Next, the participation request process and the participation determination process will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a flowchart showing participation request processing in the control unit 111, and FIG. 5 is a flowchart showing participation determination processing in the control unit 111.

  The participation request process shown in FIG. 4 is performed by the participation request processing program stored and stored in the storage unit 112 or the like being read and executed by the control unit 111, whereby the control unit 111 can It functions as a participation request means and a participation means. Further, the participation determination processing shown in FIG. 5 is performed by the participation determination processing program stored and stored in the storage unit 112 or the like being read and executed by the control unit 111, whereby the control unit 111 can It functions as a participation condition determination means and an acceptance notification means.

  The participation request processing program and the participation determination processing program may be downloaded from a predetermined server on the Internet, for example, or may be recorded on a recording medium such as a CD-ROM and the drive of the recording medium may be used. It may be configured to be read through.

  First, the participation request process shown in FIG. 4 is transmitted, for example, in step S6 in the representative selection process, and the node apparatus that has received the representative selection information or the representative selection process is selected as the representative. This is performed by the node device that is determined to be. Here, the node device 10 will be described as an example.

  When the participation request process is started in the node device 10 in the first layer overlay network 101, the control unit 111 transmits another node device (for example, a super node described later) participating in the second layer overlay network 102. The IP address of the device is acquired (step S11). For example, one or a plurality of super node devices that always exist in the system S and preferentially function as connection destinations when a representative node device participates in an upper layer, are present in each layer from the beginning. All node devices store information (for example, node ID and IP address) related to the super node device in the storage unit 112 as a setting file. This setting file exists, for example, at the time of shipment of the node device or at the initial state when the software is first installed. It is also possible to distribute and update the entire system S using the data distribution function.

  Next, the control unit 111 notifies the participation request to other node devices (for example, super node devices) participating in the second-layer overlay network 102 based on the acquired IP address as a participation request unit. (Step S12).

  On the other hand, another node device (for example, super node device) that has received the participation request starts the participation determination process shown in FIG. 5, and the control unit 111 sets a predetermined participation condition as a participation condition determination unit. Whether or not it is satisfied is determined. For example, the control unit 111 acquires information on the current maximum number of connections stored in the storage unit 112, for example (step S21), and determines whether the maximum number of connections has been reached (step S22). Note that the participation condition is not limited to the condition indicating whether or not the maximum number of connections has been reached. For example, whether or not the participation condition is the maximum number of participation in the overlay network of the layer may be set as the participation condition. .

  When the control unit 111 of another node device (for example, a super node device) determines that the maximum number of connections has not been reached (step S22: N), the node that has made a participation request as an acceptance notification unit An acceptance notification for the participation request is sent to the device 10 (information indicating the acceptance is transmitted) (step S23). On the other hand, when the control unit 111 determines that the maximum number of connections has been reached (step S22: Y), the control unit 111 notifies the node apparatus 10 that has made the participation request a rejection of the participation request (step S24). .

  On the other hand, the control unit 111 of the node device 10 that has made the participation request receives the acceptance notification or the rejection notification, and determines whether or not the participation request is accepted in the process of FIG. 4 (step S13). If it is determined that the request is not accepted (step S13: N), that is, if there is a rejection notice (received), the process is terminated. On the other hand, when it is determined that the control unit 111 has been accepted (step S13: Y), that is, when there is an acceptance notification (received), the overlay network 102 of the second layer corresponding to the upper layer is used as a participation means. A participation process for participating in the process is performed (step S14). Specifically, in the participation process, the node device 10 obtains information (node ID, IP address, etc.) regarding the node device that is in the vicinity of the node device from the node device (for example, the super node device) that has accepted the participation request. In addition, the DHT in which the node ID hashed by the hash function of the second-layer overlay network 102 is registered is acquired. As a result, the node device 10 participates in the second-layer overlay network 102.

  In the description of the participation request process and the participation determination process, the case where a node device selected as a representative in the first layer overlay network 101 participates in the second layer overlay network 102 has been described. Even when a node device selected as a representative in the hierarchical overlay network 101 participates in the third hierarchical overlay network 102, the participation request processing and participation determination processing are performed.

(Log collection processing)
Next, the log collection processing will be described with reference to FIG.

  FIG. 6 is a flowchart showing log collection processing in the control unit 111. The log collection processing shown in FIG. 6 is performed by reading and executing a log collection processing program stored and stored in the storage unit 112 or the like by the control unit 111, whereby the control unit 111 can It functions as a log collection unit, a collection log transmission unit, and a collection log acquisition unit.

  The log collection processing program may be downloaded from a predetermined server on the Internet, for example, or may be recorded on a recording medium such as a CD-ROM and read via a drive of the recording medium. It may be.

  This log collection processing is performed at substantially the same timing in a plurality of node devices (for example, all node devices participating in the first-layer overlay network 101). When a log collection command is executed in a node device (for example, a super node device) (for example, according to an operation instruction of an administrator who is a user of the node device), an arbitrary node device to a neighboring node device The start command is transmitted and transmitted to all the node devices in the first layer overlay network 101 in a sequential manner. Each node device starts log collection processing upon receipt of the start command. Here, the node device 12 will be described as an example.

  When the log collection processing is started in the node device 12, the control unit 111 first determines whether or not it is a representative node device of the log aggregation hierarchy (here, the overlay network 101 of the first hierarchy). (Step S31) When the node device is not a representative node device (Step S31: N), the process ends.

  On the other hand, if it is a representative node device in the log aggregation hierarchy (step S31: Y), the control unit 111 obtains IP addresses of neighboring node devices that can directly communicate with itself in the overlay network 101 in the first hierarchy. (Step S32).

  Next, the control unit 111 communicates with each neighboring node device corresponding to the acquired IP address, and collects the above-described operation log stored in the neighboring node device as a log collecting unit (Step S110). S33). For example, the node device 12 acquires an operation log from each of the neighboring node devices 4, 11, 13, and 20.

  Next, the control unit 111 collects all collected operation logs as a collection log as a collection log transmission unit, and collects the collected logs, for example, neighboring nodes to which the node device 12 can directly connect in the second layer overlay network 102. It transmits to the representative node devices 4, 10, 14, 20 (step S34).

  Next, the control unit 111 uses other representative node devices (for example, neighboring representative node devices 4, 10, 14, and 20 to which the node device 12 can be directly connected in the second-layer overlay network 102) as a collection log acquisition unit. The collected logs collected in step S35 are acquired from the other representative node device (step S35), and the collected logs and the collected logs acquired from the other representative node devices are totaled and stored in the storage unit 112 (for example, A table in which the node ID and IP address of each node device and the operation log are associated is created and stored). Thereby, each representative node device can share the collected log with neighboring node devices.

  Next, based on the operation log of each node device included in the collection log, the control unit 111 generates billing information including information related to the content usage fee charged to the user of each node device (step S36). For example, a fee set for the acquired content data or a fee proportional to the viewing time of the content data is calculated as the content usage fee and is included in the billing information. The billing information generated in this way is transmitted to each node device from the representative node device that generated it, for example.

  In the above description of the log collection processing, the case where the representative node device in the second-layer overlay network 102 collects logs has been described. However, the representative node device in the third-layer overlay network 103 collects logs. In such a case, the log collection process is performed. In this case, the node device 12 acquires a collection log from each of the neighboring representative node devices 4, 10, 14, 20 that can be directly connected in the second layer overlay network 102, and further, the third layer overlay network 103. The collected logs are exchanged with the neighboring representative node devices 4, 8, 16, and 20 that can be directly connected to each other. Therefore, the higher the overlay network of the upper layer, the more the operation log of a wider range (more node devices) can be collected and shared by the representative node device in the content distribution system S.

  As described above, according to the above-described embodiment, only a specific node device selected as a representative in the lowest layer (first layer) overlay network 101 is extracted and newly placed on the lowest layer overlay network 101. Therefore, each representative node device collects neighboring operation logs as collection logs and exchanges them with the collected logs collected in other representative node devices. The collection log can be shared between the node devices, the log can be collected more efficiently from the entire system S without using the management server, and the billing information can be generated based on this.

  In addition, by constructing an overlay network with three or more layers as necessary, the operation logs of the node devices of the entire system S are eventually collected as compared with collecting all node devices in the overlay network 101 in the lowest layer. The higher the hierarchy, the more efficiently it can be collected and aggregated from a very small number of node devices.

  In addition, since the operation log collected in each representative node device is exchanged and shared with a neighboring representative node device, the operation log of a specific node device is stored and saved redundantly in a plurality of representative node devices. Log reliability can be improved by collating duplicate contents.

  Further, system management information such as billing information generated in the representative node device is accessed from the node device in the lower layer overlay network not participating in the layer overlay network in which the representative node device participates. As a result, the representative node device can behave as if it has acquired the administrator authority. A major feature of P2P type systems is that all node devices participating in the overlay network are functionally equivalent. However, when it is necessary to manage the entire system, the node devices or user It is necessary to separate the authority into administrator authority for security. However, according to the above-described embodiment, the node device has an equivalent function, but since the administrator authority is acquired only after participating in the overlay network of a higher hierarchy, all the node devices have the same function. Can be designed with.

  In the above embodiment, the administrator authority and role may be set differently for each overlay network in each layer. For example, the representative node device in the second layer overlay network 102 and the representative node device in the third layer overlay network 103 differ in the contents of logs to be collected and the contents of logs to be collected, or the collection ranges are different. You may comprise so that it may. According to this configuration, the security of management information such as system management and billing information can be improved.

  In addition, by using a known theory (CDHT, Pastry, Coral) that takes into account regional attribute information related to the physical connection position between each node device on the content distribution system S, the selected node device is It is also possible to collect regional data by representing a geographical area. For example, when a node device (participating) in the lowest layer overlay network is compared to each household, a representative node device selected in consideration of regional characteristics from the lowest layer (first layer) directly joins the node device. The overlay network of the hierarchy (second hierarchy) is the town council, the overlay network of the hierarchy immediately above (third hierarchy) is the city council, the overlay network of the hierarchy immediately above (fourth hierarchy) is the prefectural council, and the hierarchy immediately above The (5th layer) overlay network can also be configured as a set of regional representative node devices such as the Diet. In this case, logs and billing information collected in the overlay network in each hierarchy are aggregated by town, aggregated by city, aggregated by prefecture, and aggregated by country.

It is a figure showing an example of outline composition of a contents distribution system concerning this embodiment. 2 is a diagram illustrating a schematic configuration example of a node device 1. FIG. It is a flowchart which shows the representative selection process in the control part. It is a flowchart which shows the participation request process in the control part 111. It is a flowchart which shows the participation determination process in the control part 111. FIG. 5 is a flowchart showing log collection processing in a control unit 111.

Explanation of symbols

1 to 23 Node device 111 Control unit 112 Storage unit 113 Buffer memory 114 Decoder unit 115 Video processing unit 116 Display unit 117 Audio processing unit 118 Speaker 119 Encoder unit 120 Communication unit 121 Input unit 122 Bus S Content distribution system

Claims (14)

An information communication system in which an overlay network is formed by the participation of all or part of a plurality of node devices physically connected to each other via communication means,
A plurality of node devices are selected as representatives from among the plurality of node devices participating in the overlay network, and an upper overlay network is formed by the participation of the plurality of node devices selected as the representatives. An information communication system. The information communication system according to claim 1,
The overlay network is formed of N (N is a natural number of 2 or more) layers,
The Nth layer overlay network is formed by the participation of some of the plurality of node devices selected as representatives from among the plurality of node devices participating in the N-1th layer overlay network. A characteristic information communication system. The information communication system according to claim 1 or 2,
Each of the node devices participating in any one of the overlay networks can directly communicate with only some of the node devices among all the other node devices participating in the overlay network. An information communication system. The representative node device included in the information communication system according to claim 3,
Log collection means for collecting logs from the other node devices capable of direct communication;
Collection log transmission means for transmitting the collected log as a collection log to another representative node device;
Collection log acquisition means for acquiring the collection log collected in the other representative node device from the other representative node device;
A node device comprising: The node device included in the information communication system according to claim 3,
Representative candidate selection means for selecting at least one node device that satisfies a predetermined representative candidate selection condition from among the other node devices that can directly communicate with each other and a plurality of node devices including itself;
Representative candidate information acquisition means for acquiring representative candidate information indicating at least one representative candidate node device selected in the other node device capable of direct communication from the other node device capable of direct communication;
At least a node device that satisfies a predetermined representative selection condition among the representative candidate node device selected by the representative candidate selection unit and the representative candidate node device indicated by the acquired representative candidate information. Representative selection means to select one,
Determining means for determining whether the node device selected as the representative is self;
When it is determined that it is not self, a transmission unit that transmits representative selection information indicating that it is selected as a representative to the node device selected as a representative by the representative selection unit;
A node device comprising: The node device according to claim 5, wherein
If it is determined by the determination means that it is self, a participation request for requesting participation to other node devices participating in the overlay network corresponding to a higher layer of the overlay network in which the self participates Means,
When there is an acceptance notification for the participation request from the other node device, a participation unit for performing a participation process for participating in the overlay network corresponding to the upper layer,
A node device comprising: A node device that receives the representative selection information transmitted from the node device according to claim 5,
When the representative selection information is received, a participation request unit that makes a participation request to another node device participating in the overlay network corresponding to an upper layer of the overlay network in which the participant participates,
When there is an acceptance notification for the participation request from the other node device, a participation unit for performing a participation process for participating in the overlay network corresponding to the upper layer,
A node device comprising: A node device that receives a participation request from the node device according to claim 6 or 7,
When receiving the participation request, participation condition determining means for determining whether or not a predetermined participation condition is satisfied,
If the participation condition is satisfied, an acceptance notification means for performing an acceptance notification for the participation request to the node device that has made the participation request;
A node device comprising: A network formation method in an information communication system in which an overlay network is formed by participation of all or some of a plurality of node devices physically connected to each other via a communication means,
A plurality of node devices selected from among the plurality of node devices participating in the overlay network as representatives;
Forming a higher-level overlay network by participation of the plurality of node devices selected as the representative;
An overlay network forming method characterized by the above. A computer included in the representative node device included in the information communication system according to claim 3,
Log collection means for collecting logs from the other node devices capable of direct communication;
Collection log transmission means for transmitting the collected log as a collection log to another representative node device, and
A log collection processing program for causing a collected log collected in the other representative node device to function as a collected log obtaining unit for obtaining the collected log from the other representative node device. A computer included in the node device included in the information communication system according to claim 3,
Representative candidate selection means for selecting at least one node device that satisfies a predetermined representative candidate selection condition from among the other node devices that can communicate directly and a plurality of node devices including itself,
Representative candidate information acquisition means for acquiring representative candidate information indicating at least one representative candidate node device selected in the other node device capable of direct communication from the other node device capable of direct communication;
At least a node device that satisfies a predetermined representative selection condition among the representative candidate node device selected by the representative candidate selection unit and the representative candidate node device indicated by the acquired representative candidate information. Representative selection means to select one,
Determining means for determining whether or not the node device selected as the representative is self; and
When it is determined that it is not self, the node device selected as a representative by the representative selection means is made to function as a transmission means for transmitting representative selection information indicating that it has been selected as a representative. Representative selection processing program. A computer included in the node device that receives the representative selection information transmitted from the node device according to claim 7,
When the representative selection information is received, a participation request unit that makes a participation request to another node device participating in the overlay network corresponding to an upper layer of the overlay network in which the self participates, and
A participation request processing program that functions as a participation means for performing a participation process for participating in an overlay network corresponding to the upper layer when there is an acceptance notification for the participation request from the other node device. A computer included in a node device that receives a participation request from the node device according to claim 8,
When receiving the participation request, participation condition determining means for determining whether or not a predetermined participation condition is satisfied, and
When the participation condition is satisfied, the participation determination processing program causes the node device that has made the participation request to function as an acceptance notification unit that issues an acceptance notification to the participation request.   14. A recording medium on which the program according to any one of 10 to 13 is recorded so as to be readable by a computer.