WO2019230375A1

WO2019230375A1 - Data distribution system, data distribution method, communication control device, communication control program, distributor node, distribution processing program, receiving node, and receiving processing program

Info

Publication number: WO2019230375A1
Application number: PCT/JP2019/019142
Authority: WO
Inventors: 中川　聰
Original assignee: 沖電気工業株式会社
Priority date: 2018-05-30
Filing date: 2019-05-14
Publication date: 2019-12-05
Also published as: JP2019207644A; JP7091847B2

Abstract

Provided is a data distribution system comprising: distributor nodes serving as distributors of distribution data; a plurality of receiving nodes which are capable of receiving distribution data from either the distributor nodes or other receiving nodes and carrying out a prescribed process thereon, and redistributing the received distribution data to other receiving nodes; and a communication control device for controlling the communication between the distributor nodes and each of the receiving nodes. The communication control device comprises: a distribution tree management part for, in accordance with selection of a parent node selection part, managing the configuration of a distribution tree configured by the distributor nodes and the receiving nodes; and a communication control part for, in accordance with the configuration of the distribution tree being managed by the distribution tree management part, controlling the communication between the distributor nodes and each of the receiving nodes. Each of the distributor nodes comprises a distribution data transmission part for transmitting distribution data in accordance with communication control by the communication control device. Each of the receiving nodes comprises a distribution data transceiver part for transmitting and/or receiving the distribution data according to the control by the communication control device.

Description

Data distribution system, data distribution method, communication control device, communication control program, distribution source node, distribution processing program, reception node, and reception processing program

The present disclosure relates to a data distribution system, a data distribution method, a communication control apparatus, a communication control program, a distribution source node, a distribution processing program, a reception node, and a reception processing program, for example, multimedia data such as video information and audio information. The present invention can be applied to a system for distributing from a distribution source to a plurality of users.

In recent years, with the development of information and communication technology, technology that allows people at distant places to communicate as if they were in the same place, or to perform collaborative work, has attracted attention. By distributing information such as a plurality of images and sounds to a plurality of locations and a plurality of users, communication between these remote multiple persons is realized. When distributing video, audio, and other data to multiple users, a distribution source with multimedia data from a video source such as a video camera or an audio source such as a microphone can provide IP to users who request these data. A distribution method using unicast communication using a packet or the like is used.

In such unicast communication, if the number of users requesting the same data increases, the distribution server replicates and distributes the same data as many as the number of unicast communication paths according to the number of users, so the network bandwidth is reduced. There is a problem that it is wasted and cannot be distributed to a sufficient number of users (see FIG. 6). In addition, there is a method to prevent waste of network bandwidth by duplicating data using multicast communication instead of unicast communication in the middle of the distribution route, but all routers on the route support multicast communication. It is necessary and is not widely used (see FIG. 7).

A technique called application level multicast is known as a countermeasure against the above problems. Application multicast is a method of realizing multicast to a large number of users only with applications between users by redistributing to another user a user (user computer) receiving distribution (user computer) and further redistributing to another user. Yes (see FIG. 8).

In a system that distributes data using application-level multicast, how the distribution route is constructed greatly affects the distribution performance of the entire system.

Japanese Patent Application Laid-Open No. 2007-235681 discloses a method of switching a distribution tree according to a situation by measuring a distribution path throughput of a distribution tree that performs data distribution using application level multicast. . In the data distribution system using application multicast, as an initial distribution tree construction method, for example, there is a method using a measurement result based on a network delay between a new node and each node. Japanese Laid-Open Patent Publication No. 2007-235681 discloses a method of constructing a distribution tree based on measurement results such as actual throughput estimated from past throughput storage.

However, in a data distribution system using application multicast, when a new node for which a measurement result of throughput is not obtained without participating in a physical network configuration such as an actual router is to participate in the distribution tree, The only option is to build a distribution tree by selecting a node that can be distributed randomly as the parent node of the new node. Therefore, the data distribution system using the application multicast has a problem such as an inefficient distribution tree until a sufficient measurement result is obtained.

In a data distribution system using application multicast, it is not preferable to transmit / receive data other than actual distribution data to / from a large number of nodes for the purpose of measuring throughput or the like. In particular, in a data distribution system using application multicast, when you want to participate in the distribution tree earlier than the measurement results can be collected, such as real-time video distribution, or when the parent node that received the distribution leaves There is a possibility that the distribution tree cannot be reconstructed quickly.

Therefore, a data distribution system, data distribution method, and communication control capable of more efficiently constructing a distribution tree composed of a distribution source node that is a distribution data distribution source and a plurality of receiving nodes that receive distribution data distribution An apparatus, a communication control program, a distribution source node, a distribution processing program, a reception node, and a reception processing program are desired.

In the first aspect, a distribution source node that is a distribution data distribution source, receives distribution data from the distribution source node or another receiving node, performs predetermined processing, and transmits the received distribution data to another receiving node. In a data distribution system having a plurality of receiving nodes that can be redistributed with respect to each other, and a communication control device that controls communication between the distribution source node and each of the receiving nodes, (1) the communication control device includes: (1-1) a node information acquisition unit that acquires node information including an IP address for the distribution source node and the respective reception nodes; and (1-2) the distribution source for each of the reception nodes. From a candidate node that is a candidate for a parent node from a node and another receiving node, an IP address of the receiving node that is a parent node selection target, A parent node selection unit that selects a parent node of the receiving node as a parent node selection target from the candidate nodes according to a bit length that matches the IP address of the candidate node; and (1-3) the parent node A distribution tree management unit that manages a configuration of a distribution tree configured by the distribution source node and the reception node according to the determination of the selection unit; and (1-4) of the distribution tree managed by the distribution tree management unit And (2) each of the distribution source nodes transmits distribution data according to the communication control of the communication control device. (3) Each receiving node transmits and receives distribution data according to control of the communication control device. Having.

The second mode is a distribution source node that is a distribution source of distribution data, receives distribution data from the distribution source node or another receiving node, performs a predetermined process, and receives the received distribution data from another receiving node. In a data distribution method for a data distribution system, comprising: a plurality of receiving nodes that can be redistributed to a communication node; and a communication control device that controls communication between the distribution source node and each of the receiving nodes. The communication control device includes a node information acquisition unit, a parent node selection unit, a distribution tree management unit, and a communication control unit. (2) The distribution source node includes a distribution data transmission unit, (3) The reception node has a distribution data transmission / reception unit, and (4) the node information acquisition unit is a node including an IP address for the distribution source node and each of the reception nodes. (5) The parent node selection unit, for each receiving node, selects a parent node from candidate nodes that are candidates for the parent node from the distribution source node and other receiving nodes. Select the parent node of the receiving node to be a parent node selection target from the candidate nodes, according to the bit length that matches the IP address of the receiving node and the IP address of each candidate node, 6) The distribution tree management unit manages a configuration of a distribution tree composed of the distribution source node and the reception node according to the determination of the parent node selection unit, and (7) the communication control unit According to the configuration of the distribution tree managed by the management unit, the communication of the distribution source node and each of the receiving nodes is controlled. (8) The distribution data transmission unit is Performs transmission of the distribution data according to the communication control of the communication control device, (9) the distribution data transceiver in accordance with the control of the communication control apparatus transmits and receives the distribution data.

The third mode is a distribution source node that is a distribution source of distribution data, receives distribution data from the distribution source node or another receiving node, performs predetermined processing, and transmits the received distribution data to other receiving nodes. In a communication control apparatus that controls a distribution tree composed of a plurality of receiving nodes that can be redistributed to (1), (1) node information including IP addresses for the distribution source node and each of the receiving nodes (2) for each of the receiving nodes, the candidate node that is a candidate for the parent node from the distribution source node and the other receiving nodes is the parent node selection target According to the bit length that matches the IP address of the receiving node and the IP address of each of the candidate nodes, the candidate node to the parent node A parent node selection unit for selecting a parent node of the reception node to be selected; and (4) managing a configuration of a distribution tree composed of the distribution source node and the reception node according to the determination of the parent node selection unit. And a distribution tree management unit.

The communication control program according to the fourth aspect receives a distribution data from a distribution source node that is a distribution data distribution source and the distribution source node or another receiving node, performs a predetermined process, and receives the received distribution data. (1) The distribution source node and each of the receptions are provided in a computer mounted on a communication control device that controls a distribution tree composed of a plurality of reception nodes that can be redistributed to other reception nodes. Node information including an IP address is obtained for a node, and (2) for each receiving node, selection of a parent node from candidate nodes that are candidates for a parent node from the distribution source node and other receiving nodes According to the bit length that matches the IP address of the target receiving node and the IP address of each candidate node, the candidate node A parent node of the receiving node to be selected as a parent node is selected from the node, and (3) a process of managing a configuration of a distribution tree composed of the distribution source node and the receiving node is executed according to the selection .

The distribution source node according to the fifth aspect includes a distribution data transmission unit that transmits distribution data according to the communication control of the communication control device according to the second aspect.

The distribution processing program according to the sixth aspect causes a computer mounted on the distribution source node to execute processing for transmitting distribution data according to the communication control of the communication control device according to the second aspect.

The reception node according to the seventh aspect includes a distribution data transmission / reception unit that transmits and receives distribution data according to the communication control of the communication control device according to the second aspect.

The reception processing program according to the eighth aspect causes a computer mounted on the reception node to execute processing for transmitting and receiving distribution data according to the communication control of the communication control device according to the second aspect.

According to the present disclosure, it is possible to more efficiently construct a distribution tree including a distribution source node that is a distribution data distribution source and a plurality of reception nodes that receive distribution data.

It is the block diagram shown about the functional structure of the delivery structure management server which concerns on embodiment. It is the block diagram shown about the example of the whole structure of the data delivery system which concerns on embodiment. It is the block diagram shown about the functional structure of the receiving node which concerns on embodiment. It is the block diagram shown about the functional structure of the delivery origin node which concerns on embodiment. It is explanatory drawing shown about the example of the physical structure of a network which comprises the data delivery system which concerns on embodiment, and an IP address structure. It is explanatory drawing shown about the example of the data delivery by the unicast of related technology. It is explanatory drawing shown about the example of the data delivery by multicast of related technology. It is explanatory drawing shown about the example of the data delivery by the application level multicast of related technology.

(A) Main Embodiment Hereinafter, an embodiment of a data distribution system, a data distribution method, a communication control device, a communication control program, a distribution source node, a distribution processing program, a reception node, and a reception processing program according to the present disclosure will be described. This will be described in detail with reference. Hereinafter, an example in which the communication control device and the communication control program of the present disclosure are applied to the distribution configuration management server will be described.

(A-1) Configuration of Embodiment FIG. 2 is a block diagram showing the overall configuration (logical connection configuration) of the data distribution system 1 of this embodiment.

As shown in FIG. 2, the data distribution system 1 includes a distribution configuration management server 10, a distribution source node 20, and five reception nodes 30 (30-1 to 30-5). In the data distribution system 1, the number of devices arranged is not limited. In the data distribution system 1, the connection means (network configuration) between the devices is not limited. For example, the Internet, a wide area LAN, a wireless IP network, etc. can be applied.

The distribution configuration management server 10 is a device that manages the configuration of a distribution tree formed by the distribution source node 20 and each receiving node 30.

The distribution source node 20 is a device that is a distribution source of data (hereinafter also referred to as “distributed data”) distributed to each receiving node 30. The contents and format of the distribution data are not limited. For example, content data such as video and audio (for example, data converted into a streaming format based on video data in a file format) and video from a video source such as a video camera Multimedia data (multimedia information) such as data and acoustic data from an audio source such as a microphone. The distribution data may be data such as a document or a presentation other than video and audio data. Under the control of the distribution configuration management server 10, the distribution source node 20 transmits distribution data to a child node (a reception node 30 that is a direct distribution destination) on the distribution tree among the plurality of reception nodes 30. Do.

The receiving node 30 receives distribution data from the parent node (distribution source node 20 or other receiving node 30) under the control of the distribution configuration management server 10, and uses predetermined processing (for example, a display, a speaker, or the like). This is an apparatus that performs (output processing) and redistributes received distribution data to a child node (another reception node 30).

The distribution configuration management server 10 manages the configuration of the distribution tree between the distribution source node 20 and the reception node 30, and reconfiguration of the distribution tree when the new reception node 30 participates or when the reception node 30 leaves. At this time, communication control (for example, a distribution tree configuration instruction) is performed on the distribution source node 20 and the reception node 30.

Note that a plurality of distribution source nodes 20 may exist, and the distribution configuration management server 10 may manage the distribution tree for each distribution source. For example, the distribution source node 20 may be arranged at each of a plurality of bases, and communication may be realized by bidirectionally distributing data between the plurality of bases.

Next, the internal configuration of the distribution configuration management server 10 will be described with reference to FIG.

FIG. 1 is a block diagram showing a functional configuration of the distribution configuration management server 10.

The distribution configuration management server 10 includes a distribution configuration management unit 11 that manages at least the configuration of a distribution tree starting from the distribution source node 20. The distribution configuration management unit 11 includes a parent node determination processing unit 110, a target node information acquisition unit 120, and an information transmission unit 130.

The distribution configuration management server 10 may be configured, for example, by installing a program (including the communication control program according to the embodiment) in a computer such as a PC or a workstation.

The parent node determination processing unit 110 performs a process of determining a parent node (a node that directly receives distribution data) of each receiving node 30 when the distribution tree is configured / reconfigured.

The target node information acquisition unit 120 performs processing for acquiring information (hereinafter referred to as “node information”) regarding the receiving node 30 (hereinafter also referred to as “target node”) that is a target for determining a parent node.

The information transmitting unit 130 performs communication control processing (corresponding to parent node information) on each receiving node 30 based on information on the parent node determined by the parent node determination processing unit 110 (hereinafter also referred to as “parent node information”). Distribution control (communication control processing for setting a parent node and a child node). For example, the information transmission unit 130 transmits information about the parent node (for example, information including the network address) to the target node (child node) in the parent node information, and the parent node (parent of the target node) in the parent node information. You may make it set a delivery path | route by transmitting the information (for example, information containing a network address) regarding a child node (target node) to a node. As described above, communication control of the distribution source node 20 and each reception node 30 is performed by the information transmission unit 130, and configuration / reconfiguration of the distribution tree is performed.

Next, the internal configuration of the parent node determination processing unit 110 will be described.

The parent node determination processing unit 110 includes a network address distance calculation unit 111, a parent node selection unit 112, a distribution tree storage unit 113, a parent node candidate generation unit 114, and a subnet determination / distance correction unit 115.

The distribution tree storage unit 113 includes node information relating to each node (distribution source node 20 and each reception node 30) constituting the distribution tree, and information on the configuration state of the distribution tree starting from the distribution source node 20 (root) (hereinafter referred to as “distribution tree”). , Referred to as “distribution tree configuration information”) and the like.

The parent node candidate generation unit 114 adds a new node from the nodes (distribution source node 20 and each receiving node 30) participating in the distribution tree based on the distribution tree configuration information stored in the distribution tree storage unit 113. Information including the list of nodes (hereinafter referred to as “candidate nodes”) that can be the parent node of the distribution source for the target nodes (node information) that require allocation of the distribution path (determining the parent node etc.) , Referred to as “candidate node information”).

The inter-network address distance calculation unit 111 includes network address information (network address information of the target node) included in the input node information of the target node and each of the candidate node information generated by the parent node candidate generation unit 114. The distance indicating the proximity between the network address of the target node and each candidate node is calculated from the network address information of the candidate node.

The subnet determination / distance correction unit 115 determines whether the target node and the candidate node belong to the same subnetwork based on the distance calculated by the inter-network address distance calculation unit 111, and corrects the distance between the network addresses. Is. Details of the correction processing by the subnet determination / distance correction unit 115 will be described later.

The parent node selection unit 112 uses the distance information between the corrected network addresses obtained by the subnet determination / distance correction unit 115 to determine a node to be a parent node of the target node from among the candidate nodes. is there.

The parent node selection unit 112 supplies parent node information indicating the selection result of the parent node with respect to the target node to the information transmission unit 130, and the distribution tree configuration of the distribution tree storage unit 113 according to the selection result of the parent node selection unit 112 Process to update information. The parent node information includes, for example, information for specifying a distribution path composed of the target node and the parent node of the target node (for example, information including network address information of the target node and the parent node of the target node). Also good.

Next, the internal configuration of each receiving node 30 will be described with reference to FIG.

Each reception node 30 includes a reception unit 301, a reception data processing unit 302, a retransmission unit 303, and a distribution control unit 304.

The receiving node 30 is configured by installing a program (including the communication control program according to the embodiment) in a computer such as a personal computer, a workstation, a mobile device (for example, a smart phone or a tablet terminal) (for example, It may be configured to include a configuration that is downloaded and executed each time, such as JavaScript (registered trademark) of a Web browser.

The receiving unit 301 receives distribution data from the parent node.

The reception data processing unit 302 performs predetermined processing (for example, display output processing to the user using a display or a speaker) on the distribution data received from the parent node.

The re-transmission unit 303 performs re-transmission processing of distribution data to other receiving nodes 30 (child nodes) under the control of the distribution control unit 304.

The distribution control unit 304 performs processing for controlling transmission / reception processing (processing by the reception unit 301 and the retransmission unit 303).

In the receiving node 30, the receiving unit 301, the retransmitting unit 303, and the distribution control unit 304 constitute a distribution data transmitting / receiving unit that transmits and receives distribution data.

Next, the internal configuration of each distribution source node 20 will be described with reference to FIG.

Each distribution source node 20 includes a transmission unit 201, an acquisition unit 202, and a distribution control unit 203.

The distribution source node 20 is configured by installing a program (including the distribution processing program according to the embodiment) on a computer such as a PC, a workstation, or a mobile terminal (for example, a smart phone or a tablet terminal) (for example, It may be configured to include a configuration that is downloaded and executed each time, such as JavaScript of a Web browser.

The acquisition unit 202 holds distribution data. The method by which the acquisition unit 202 holds distribution data is not limited. For example, the acquisition unit 202 may acquire distribution data as batch data (for example, a video data file recorded in an external storage) or sequentially acquire distribution data from a source such as a camera or a microphone. You may make it do.

The transmission unit 201 performs a process of distributing (transmitting) the distribution data acquired by the acquisition unit 202 to a distribution destination (receiving node 30 serving as a child node) according to the control of the distribution control unit 203.

The distribution control unit 203 performs processing for controlling distribution processing by the transmission unit 201 and the like.

In the distribution source node 20, the transmission unit 201 and the distribution control unit 203 constitute a distribution data transmission unit that transmits distribution data.

(A-2) Operation of Embodiment Next, the operation of the data distribution system 1 of this embodiment having the above configuration will be described.

First, an outline of a distribution tree configuration procedure in the data distribution system 1 will be described.

As shown in FIG. 2, in the data distribution system 1, an application level multicast is transmitted from a distribution source node 20 that is a distribution data distribution source to a plurality of reception nodes 30 that are distribution data distribution destinations (receivers). Distribution data is distributed using.

In the data distribution system 1, the distribution tree structure information is managed by the distribution configuration management server 10. The distribution configuration management server 10 operates by exchanging node information regarding each node and information regarding the configuration of the distribution tree with each node (distribution source node 20 and receiving node 30) configuring the distribution tree. The distribution tree is reconstructed according to the addition and removal of nodes. In the following description, only matters related to the configuration of the distribution tree will be described, but any method can be used for signaling or the like for setting a communication path serving as a distribution path. For example, the distribution configuration management server 10 may serve as a signaling server that relays signaling between nodes.

First, it is assumed that the distribution control unit 203 of the distribution source node 20 notifies the distribution configuration management server 10 of node information including IP address information as its network address information. It is assumed that the distribution control unit 304 of the receiving node 30 notifies the distribution configuration management server 10 of node information including IP address information as its network address information. Hereinafter, an example in which an IP address (IPv4 address) is used as a network address in the data distribution system 1 will be described.

The distribution configuration management server 10 determines the configuration of the distribution tree by storing node information from the distribution source node 20 and the reception node (s) 30 in the distribution configuration management unit 11 which is the main component. The node is notified of information related to the connection partner of the distribution path.

Each node of the distribution source node 20 and the reception node 30 secures a communication path with the connection partner according to the distribution path constituting the distribution tree, and the distribution source node 20 transmits the distribution data held by itself to the reception node 30. Receives the distribution data from the parent node and retransmits the received distribution data if it has child nodes. When a new receiving node 30 participates in the distribution tree, the distribution configuration management server 10 determines the parent node of the newly participating receiving node 30 according to the node information notified from the newly participating receiving node 30 (target node). assign. Then, when the assigned parent node starts distribution to the new receiving node 30, the distribution tree is constructed (reconstructed).

When one of the receiving nodes 30 participating in the distribution tree leaves the distribution tree, distribution to the receiving node 30 having the separated receiving node 30 as a parent node (or an ancestor node) stops. Therefore, the distribution configuration management server 10 assigns a new parent node to the receiving node 30 whose distribution stops. In the distribution configuration management server 10, the reassignment of the parent node may be performed only for the direct child node of the leaving node, or it may be reassigned not only for the direct child node but also for the descendant node of the child node. Allocation may be performed. The distribution configuration management server 10 reconstructs the distribution tree by reassigning parent nodes to these receiving nodes 30.

Next, details of a process in which the distribution configuration management unit 11 of the distribution configuration management server 10 determines a parent node for each node will be described.

As described above, in the distribution configuration management unit 11, the parent node determination processing unit 110 performs a process of determining a distribution source parent node for a node that needs to be assigned a parent node.

When the parent node determination processing unit 110 receives information (target node information) related to the node to which the parent node is assigned, information including IP address information is acquired from the target node information. Then, the parent node determination processing unit 110 selects a parent node based on the acquired target node information, and outputs parent node information indicating the selection result.

The distribution tree storage unit 113 stores distribution tree configuration information indicating a current distribution tree configuration state (connection state) and node information of each node participating in the distribution tree.

When the node information of the target node is input, the parent node candidate generation unit 114 refers to the information stored in the distribution tree storage unit 113, and each node participating in the distribution tree (the distribution source node 20 and the distribution node 20). Among each receiving node 30), a node capable of distributing distribution data to the target node is detected as a candidate node. In the case of the reconfiguration accompanying the leaving of the node, the node is not included in the candidate node because it is not a node that can be distributed even if a descendant node of the target node is a parent node (a node that can reach the distribution source node 20). At this time, in the parent node selection unit 112, for example, a preset upper limit of the number of branches of the tree (number of child nodes), an upper limit of the depth of the distribution tree from the distribution source node 20 (number of via nodes), etc. A node that does not satisfy the condition may be configured not to be a candidate node.

Next, the inter-network address distance calculation unit 111 determines, for each candidate node, an IP address corresponding to the proximity between the IP addresses based on the IP address information of the target node and the IP address information of each candidate node. Calculate the distance. A method for calculating the distance between IP addresses will be described later.

Next, the subnet determination / distance correction unit 115 determines whether the target node and each candidate node belong to the same subnetwork based on the distance between IP addresses calculated by the inter-network address distance calculation unit 111. If it is determined that it belongs to the sub-network, the distance between IP addresses is corrected.

Next, the parent node selection unit 112 selects an optimal parent node for the target node from among the candidate nodes using information such as the corrected distance between IP addresses for each obtained candidate node, and based on the selection result Output parent node information. In addition, the parent node selection unit 112 updates the distribution tree configuration information in the distribution tree storage unit 113 based on the determined connection relationship between the target node and the parent node. Further, the parent node selection unit 112 manages node information regarding the target node on the distribution tree storage unit 113 (additional storage or deletion of node information on the distribution tree storage unit 113).

As described above, the parent node selection unit 112 manages the distribution tree by updating the information stored in the distribution tree storage unit 113.

Next, a method for calculating the distance between IP addresses in the distance calculation unit 111 between network addresses will be described.

The IP address itself does not have information on the physical network connection status. However, a general IP network router uses processing such as determining a routing destination based on a route table for each IP address prefix (upper bit portion). Therefore, in a general IP network, the same physical route is used for assigning a common prefix IP address to the same organization or base, or for summarizing router route tables (summarizing table entries for the same route). In many cases, an IP address serving as a common prefix is assigned to a network passing through. Further, in a general IP network, in the same subnetwork under the same router, the prefix portion (network address portion) which is the network portion of the IP address has the same value. In other words, between the two sub-networks constituting a general IP network, the more common portions of the prefix, the more likely it can be reached with a smaller number of hops and path costs.

Therefore, in this embodiment, as an index corresponding to the distance between two IP addresses (between two nodes), the prefix match length constituting the IP address (how many bits match from the upper bits of the two IP addresses) ) Shall be used. In this case, the longer the prefix match length (the number of bits that match continuously from the most significant bit) between the two IP addresses, the shorter the distance. That is, a candidate node having a long prefix match length with the target node is preferentially selected as a parent node.

It should be noted that in the meaning of distance (such that the closer the value is, the smaller the value), the bit length of the suffix part excluding the matched prefix part (position counted from the least significant bit of the highest mismatch bit) may be used. In this case, a node having a short bit length in the suffix portion is selected as a parent node preferentially between the target node and an arbitrary candidate node.

FIG. 5 shows an example of the physical network configuration and IP address of each node.

For example, in the network shown in FIG. 5, there are three districts B1 to B3, each of which is 10.1.0.0/16, 10.2.0.0/16, and 10.3.0.0/16. Assume that you are using the bit prefix address space. In addition, it is assumed that three sub-networks SN1 to SN3 are set in the area B1. Here, the sub-networks SN1 to SN3 use 24-bit prefix address spaces of 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24, respectively. It shall be. In FIG. 5, five nodes NA, NB, NC, ND, NE are arranged. Further, in FIG. 5, a node ND is arranged in the area B2. Furthermore, in FIG. 5, nodes NA, NB, NE are arranged in the sub-network SN1 (10.1.1.0/24) of the district B1. In FIG. 5, the node NC is arranged in the sub-network SN2 (10.1.2.0/24) of the district B1.

Considering node NB in the same subnet, node NC in the same area but node NC in the same area, and node ND in a different area with respect to node NA, the IP addresses possessed by each are as follows, for example. In the following, it is assumed that an arbitrary 8-bit value is set for each of aa, bb, and cc. In the following, it is assumed that an arbitrary 16-bit value is set in “dd.dd”.
IP address of the node NA: 10.1.1. aa
IP address of node NB: 10.1.1. bb
IP address of the node NC: 10.1.2. cc
IP address of node ND: 10.2. dd. dd

プレフィックス Verify the prefix match length of nodes NB, NC, and ND for the IP address of node NA at this time. The prefix match length that matches node NA and node NB is 24 bits or more, the prefix match length that matches node NA and node NC is 16 bits or more and less than 24 bits, and the prefix match length that matches node NA and node ND is 16 bits. Less than a bit. In other words, the closer the node from the node NA to the physical network (for example, the node with the smaller number of hops and path cost), the greater the prefix match length.

As described above, if a candidate node having the maximum prefix match length calculated by the inter-network address distance calculation unit 111 is selected as the parent node, a node closer to the physical network can be selected as the parent node. It becomes.

However, for example, a node having higher distribution capability than the node NB (for example, having more CPUs) or a child node redistributing than the node NB in the same subnetwork as the nodes NA and NB Even if there is a node NE that is a small number of nodes (there is a redistributable number), the IP address of the node NE (for example, 10.1.1.ee; ee is an arbitrary 8-bit value) If the match length of the IP address of the node NB is longer than that of the IP address of the node NA (the bit pattern of the host part of the IP address is similar), the node NB is selected.

Therefore, the subnet determination / distance correction unit 115 of this embodiment determines whether the target node and the candidate node belong to the same subnetwork based on the prefix match length calculated by the inter-network address distance calculation unit 111, and the same If it is determined that it belongs to a subnetwork, the distance between network addresses is corrected assuming that only the subnetwork address part of the prefix matches, and the distance is corrected to be equal to other nodes in the same subnetwork. .

The subnet determination / distance correction unit 115 first determines whether the prefix match length of the IP address is the maximum value (32 bits for the IPv4 address) (whether all bit patterns match). In this case, it means that the target node and the candidate node are in the same device (for example, in the user terminal), and distance correction is not performed in order to distinguish from another device in the subnetwork. Next, when the prefix match length is larger than the preset subnetwork prefix length (for example, fixed to 24 bits), the subnet determination / distance correction unit 115 determines the subnetwork prefix length as the corrected distance. To do. That is, the subnet determination / distance correction unit 115 corrects the distances to a plurality of candidate nodes in the same subnetwork so as to have the same value. If the prefix match length is shorter than the predetermined subnetwork prefix length, no particular correction is performed. The subnetwork prefix length used for subnetwork judgment may differ for each individual subnetwork in an actual network, but for each known subnetwork, use the actual actual prefix length by referring to the database. In the case of an unknown subnetwork, determination may be made using a predetermined fixed value such as 24 bits. In the case of an IPv6 network, a predetermined value such as 64 bits may be used as the subnetwork prefix length.

For example, the parent node determination processing unit 110 simply selects a candidate node having the maximum prefix match length calculated by the inter-network address distance calculation unit 111 as the parent node. That is, in the example of FIG. 5, the parent node determination processing unit 110 may select the node NB as the parent node for the node NA. When there are a plurality of nodes having the maximum prefix match length corrected by the subnet determination / distance correction unit 115, for example, the parent node determination processing unit 110 randomly selects a parent using a random number or the like from these nodes. A node may be selected. Further, the parent node determination processing unit 110 may determine other parent nodes from candidate nodes having the same prefix match length in consideration of other information attached to the node information (for example, the processing capability of the node). good. In other words, in this case, the parent node determination processing unit 110 selects the node NE if the node NE has a margin of processing capability or the like rather than the node NB.

As described above, the distribution configuration management server 10 (parent node determination processing unit 110) is expected to be closer to the physical network without measuring actual throughput or the like by using the IP address information of each node. A distribution tree can be constructed by selecting possible candidate nodes as parent nodes.

Next, the operation within each receiving node 30 will be described.

The distribution control unit 304 notifies the distribution configuration management unit 11 in the distribution configuration management server 10 of node information including its own IP address information.

In the distribution control unit 304, information related to communication control (for example, information defining a distribution path of network address information of a parent node or a child node) is notified from the distribution configuration management server 10 (distribution configuration management unit 11).

The distribution control unit 304 secures a communication path between the parent node and the receiving unit 301, and starts receiving the distribution data from the parent node by the receiving unit 301.

The reception data processing unit 302 performs predetermined processing (for example, processing for displaying in the case of video data or reproduction in the case of audio data) on the received distribution data.

When the distribution configuration management server 10 (distribution configuration management unit 11) notifies the distribution control unit 304 that there is another receiving node 30 (child node) having itself as a parent node, the retransmission control unit 304 From 303, the distribution data is retransmitted to its own child node. The distribution control unit 304 does not control retransmission when there is no child node.

Through the processing as described above, the data distribution system 1 distributes distribution data using application multicast.

(A-3) Effects of Embodiment According to this embodiment, the following effects can be obtained.

In the data distribution system 1 of this embodiment, the parent node to be a distribution source is selected when newly participating in the information distribution tree using application multicast or when the distribution tree is reconstructed by leaving the parent node. It is possible to select a parent node that can be expected to be close to the physical network topology with respect to the target node that needs to be. Thereby, in the data delivery system 1 of this embodiment, it becomes possible to reduce the subject that a delivery tree becomes inefficient.

Further, in the data distribution system 1 of this embodiment, the selection can be made without actually measuring the throughput, so that a distribution tree can be quickly constructed, and extra traffic is generated for throughput measurement and the like. The amount can also be reduced.

Furthermore, in the data distribution system 1 of this embodiment, when there are a plurality of candidates for the parent node in the same subnet, reconnection or the like is performed by selecting at random or taking into consideration the processing capability of the candidate node. Nodes connected in the network are distributed, and a more efficient distribution tree can be constructed.

(B) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(B-1) In the data distribution system 1 of the above-described embodiment, the example in which the IPv4 address is used as the network address has been described. However, the distance between the IP addresses is similarly calculated using the prefix match length for the IPv6 address. It is possible. The above data distribution system 1 can also be applied to distribution systems on various networks such as an IPv6 network, other networks, and networks in which IPv4 and IPv6 are mixed.

(B-2) In the data distribution system 1 of the above-described embodiment, distribution is dynamically performed based on measurement results (communication history) such as throughput of transmission / reception of distribution data for each distribution path after actually starting distribution. You may comprise so that the method of updating a path | route may be used together. For example, in the distribution configuration management server 10 of the above embodiment, a receiving node 30 received from a distribution path that does not have a throughput is detected, and the current parent node (and target node) is set with this receiving node 30 as a target node. The distribution route may be dynamically updated by performing the same selection as described above from the parent node candidates excluding the descendant node).

Each of the communication control device, the distribution source node, and the reception node includes a CPU that is a hardware processor and a memory connected to the CPU, and the communication control device loads a program recorded in the memory to the CPU. As a result, it functions as an information acquisition unit, a parent node selection unit, a distribution tree management unit, and a communication control unit. Further, the distribution source node functions as a distribution data transmission unit by loading and executing the program recorded in the memory on the CPU, and the reception node loads and executes the program recorded in the memory on the CPU. Thus, it functions as a distribution data transmission / reception unit.

Note that programs such as a communication control program, a distribution processing program, and a reception processing program are recorded on a non-temporary recording medium such as a DVD, HDD, or SSD, and are read into a memory via a non-temporary recording medium reading device. May be.

This application claims the priority of Japanese Patent Application No. 2018-103856 filed on May 30, 2018, the entire text of which is incorporated herein by reference.

Claims

Receiving the distribution data from the distribution source node that is the distribution source of the distribution data and the distribution source node or another receiving node and performing predetermined processing, and redistributing the received distribution data to the other receiving nodes A data distribution system comprising: a plurality of receiving nodes capable of controlling communication between the distribution source node and each of the receiving nodes;
The communication control device includes:
A node information acquisition unit that acquires node information including an IP address for the distribution source node and each of the reception nodes;
For each of the receiving nodes, from the candidate node that is a candidate for the parent node from the distribution source node and the other receiving nodes, the IP address of the receiving node that is a parent node selection target, and each of the candidate nodes A parent node selection unit that selects a parent node of the receiving node to be a parent node selection target from the candidate nodes according to a bit length that matches the IP address of
A distribution tree management unit that manages a configuration of a distribution tree configured by the distribution source node and the reception node according to the selection of the parent node selection unit;
In accordance with the configuration of the distribution tree managed by the distribution tree management unit, a communication control unit that controls communication between the distribution source node and each of the receiving nodes;
Have
Each of the distribution source nodes has a distribution data transmission unit that transmits distribution data in accordance with communication control of the communication control device,
Each of the receiving nodes has a distribution data transmission / reception unit that transmits and receives distribution data according to the control of the communication control device.
Data distribution system.
The communication control device includes:
The receiving node to be selected by the parent node and each of the candidate nodes according to the matching length of the prefix portion of the IP address of the receiving node to be selected by the parent node and the IP address of each candidate node A distance calculation unit for calculating a distance indicating a network proximity to
The parent node selection unit selects, as a parent node of the receiving node that is a parent node selection target, the candidate node that is closest to the distance calculated by the distance calculation unit and the receiving node that is a parent node selection target. ,
The data distribution system according to claim 1.
The communication control device selects a parent node for each candidate node according to a matching length of a prefix part between the IP address of the receiving node to be selected as a parent node and the IP address of each candidate node. A distance correcting unit that determines whether or not the target receiving node belongs to the same subnetwork and corrects the distance calculated by the distance calculating unit according to the determination result;
The data distribution system according to claim 2, further comprising:
The distance correction unit has the same IP address of the receiving node as a selection target of the parent node and the distance between the candidate nodes having a prefix portion matching length equal to or larger than a predetermined length as the receiving node as a selection target of the parent node. 4. The data distribution system according to claim 3, wherein the data distribution system is determined to belong to a subnetwork and is corrected to a distance corresponding to the prefix length of the subnetwork.
The parent node selection unit may satisfy at least one of the conditions in which the number of tree branches is equal to or greater than a predetermined first threshold or the depth of the distribution tree from the distribution source node is equal to or greater than a second threshold. The data distribution system according to any one of claims 1 to 4, wherein the corresponding candidate node is not selected as a parent node.
The node information acquired by the node information acquisition unit includes incidental information,
The parent node selection unit selects a parent node in consideration of incidental information of each candidate node;
The data distribution system according to any one of claims 1 to 5.
The data distribution system according to claim 6, wherein, when there are a plurality of candidate nodes having a minimum distance, the parent node selection unit selects a parent node in consideration of incidental information.
The data distribution system according to claim 6 or 7, wherein the node information acquisition unit acquires, as incidental information, at least processing capability information indicating processing capability of the distribution source node and each of the receiving nodes.
The data according to claim 3 or 4, wherein, when there are a plurality of candidate nodes having a minimum distance, the parent node selection unit randomly selects a parent node from the candidate nodes having a minimum distance. Distribution system.
The parent node selection unit, after selecting a parent node for all the receiving nodes, changes a parent node of each receiving node based on a communication history for each distribution path of the distribution tree. Item 10. The data distribution system according to any one of Items 9 to 9.
The parent node selection unit, after selecting a parent node for all the receiving nodes, detects a distribution path that requires a path change based on a communication history for each distribution path of the distribution tree, and needs to change the path The data delivery system according to claim 10, wherein a parent node is selected by excluding a current parent node and a descendant node from the candidate nodes for the receiving node on a lower side of a simple delivery path.
The data distribution system according to any one of claims 1 to 11, wherein the distribution source node and each of the reception nodes transmit node information including an IP address of the own apparatus to the communication control apparatus.
The communication control device has a communication control unit that notifies child node information to the distribution source node and each of the reception nodes based on the configuration of the distribution tree managed by the distribution tree management unit,
The distribution source node transmits distribution data to the receiving node corresponding to the child node notified from the communication control device, and each of the receiving nodes corresponds to the child node notified from the communication control device. The distribution data received from the parent node is transmitted to the receiving node.
The data distribution system according to claim 12.
When the receiving node participating in the distribution tree leaves, the parent node selection unit selects a new parent node with respect to the receiving node that has received distribution data directly from the leaving receiving node The data distribution system according to any one of claims 1 to 13, wherein the processing is performed.
The parent node selection unit, when the receiving node participating in the distribution tree leaves, performs a process of selecting a new parent node for descendant nodes including child nodes of the leaving receiving node. The data distribution system described in 1.
The data distribution system includes a plurality of the distribution source nodes,
The parent node selection unit selects, for each of the receiving nodes, the distribution tree starting from the distribution source node corresponding to specific information for specifying distribution data to be distributed included in node information, Selecting a parent node from the delivery tree selected for the receiving node;
The distribution tree management unit manages a plurality of the distribution trees starting from each of the distribution source nodes.
The data distribution system according to any one of claims 1 to 15.
The distribution source node that is the distribution source of the distribution data and the distribution data are received from the distribution source node or another receiving node, and predetermined processing is performed, and the received distribution data is redistributed to other receiving nodes. A data distribution method for a data distribution system, comprising: a plurality of receiving nodes, and a communication control device that controls communication between the distribution source node and each of the receiving nodes,
The communication control device includes a node information acquisition unit, a parent node selection unit, a distribution tree management unit, and a communication control unit,
The distribution source node has a distribution data transmission unit,
Each of the receiving nodes has a distribution data transmission / reception unit,
The node information acquisition unit acquires node information including an IP address for the distribution source node and each of the receiving nodes,
The parent node selection unit, for each of the receiving nodes, from the candidate nodes that are candidates for the parent node from the distribution source node and the other receiving nodes, the IP address of the receiving node that is a parent node selection target And selecting a parent node of the receiving node to be a parent node selection target from the candidate node according to a bit length that matches with the IP address of each of the candidate nodes,
The distribution tree management unit manages a configuration of a distribution tree configured by the distribution source node and the reception node according to the selection of the parent node selection unit,
The communication control unit controls communication of the distribution source node and each of the receiving nodes according to the configuration of the distribution tree managed by the distribution tree management unit,
The distribution data transmitting unit transmits distribution data according to communication control of the communication control device,
The distribution data transmission / reception unit is a data distribution method for transmitting / receiving distribution data according to control of the communication control device.
The distribution source node that is the distribution source of the distribution data and the distribution data are received from the distribution source node or another receiving node, and predetermined processing is performed, and the received distribution data is redistributed to other receiving nodes. A communication control device for controlling a distribution tree composed of a plurality of receiving nodes capable of
A node information acquisition unit that acquires node information including an IP address for the distribution source node and each of the reception nodes;
For each of the receiving nodes, from the candidate node that is a candidate for the parent node from the distribution source node and the other receiving nodes, the IP address of the receiving node that is a parent node selection target, and each of the candidate nodes A parent node selection unit that selects a parent node of the receiving node to be a parent node selection target from the candidate nodes according to a bit length that matches the IP address of
A distribution tree management unit that manages a configuration of a distribution tree configured by the distribution source node and the reception node according to the selection of the parent node selection unit;
A communication control device.
Receiving the distribution data from the distribution source node that is the distribution source of the distribution data and the distribution source node or another receiving node and performing predetermined processing, and redistributing the received distribution data to the other receiving nodes In a computer mounted on a communication control device that controls a distribution tree composed of a plurality of receiving nodes capable of
For the distribution source node and each of the receiving nodes, obtain node information including an IP address;
For each of the receiving nodes, from the candidate node that is a candidate for the parent node from the distribution source node and the other receiving nodes, the IP address of the receiving node that is a parent node selection target, and each of the candidate nodes A parent node of the receiving node to be a parent node selection target from the candidate nodes, according to the bit length that matches with the IP address of
Managing a configuration of a distribution tree configured by the distribution source node and the reception node according to the selection;
A communication control program that executes communication control processing.
A distribution source node having a distribution data transmission unit that transmits distribution data in accordance with communication control of the communication control device according to claim 18.
On the computer installed in the distribution source node,
A distribution processing program for executing distribution processing for transmitting distribution data in accordance with communication control of the communication control device according to claim 18.
A reception node having a distribution data transmission / reception unit that transmits and receives distribution data according to communication control of the communication control device according to claim 18.
On the computer installed in the receiving node,
A reception processing program for executing transmission / reception processing for transmitting / receiving distribution data in accordance with communication control of the communication control device according to claim 18.