JP2019145938A - Network communication system - Google Patents

Abstract

To connect an inexpensive IoT device for personal use to the Internet while ensuring sufficient security.SOLUTION: For a plurality of terminal devices (600A to 600D) connected to a network (N), an address table (T) that associates terminal IDs with location addresses is prepared, and communication between terminal devices are intermediated by a connection intermediating device (500). An internal terminal device (600A) is incorporated in a gateway device (GW), and various IoT devices (701 to 705) are connected downstream thereof. When data is transmitted from external terminal devices (600B to 600D) to a specific IoT device, intermediating processing by the connection intermediating device (500) is used to deliver the data to the gateway device (GW), and the data is distributed from the gateway device (GW) to a specific IoT device.SELECTED DRAWING: Figure 22

Description

  The present invention relates to a communication system via a network, and more particularly to a network communication system that performs communication via the Internet for various IoT devices such as home appliances.

  In recent years, various devices such as personal computers and smartphones have been connected to the Internet, and inter-device communication technology via a network has become widespread. In particular, recently, based on the idea of IoT (Internet of Things), technology that connects various appliances to the Internet, ranging from home appliances to automobile electrical components, has begun to spread, and while on the go In addition, it has become possible to control IoT devices such as home appliances and automobile electrical components from a terminal device such as a smartphone via the Internet.

  In the case of a mobile terminal such as a smartphone, the location on the network changes depending on the location, so it is necessary to recognize the current location address of the communication partner in some way. From such a viewpoint, a network communication system provided with a relay device that plays a role of taking over communication between two parties has been proposed. For example, in the following Patent Document 1, a secure first communication channel is secured between a first terminal device and a relay device, and a secure second communication channel is established between the second terminal device and the relay device. There is disclosed a network communication system that secures a communication channel and performs communication between both parties via a relay device. However, in a system using such a relay device, all communication data between the two devices passes through the relay device, which causes a problem that a large processing load is applied to the relay device.

  Therefore, recently, using a protocol called SIP (Session Initiation Protocol), a connection mediating device provided on the network has taken over the establishment of the communication session between the two, A method of performing direct communication between them has been proposed. For example, Patent Documents 2 and 3 below disclose network communication systems that realize VPN communication using the SIP. Patent Document 4 below discloses a network communication system in which the method using the SIP is improved to further reduce the processing burden on the connection mediating apparatus.

JP 2005-229436 A JP 2010-233167 A JP 2013-038864 A International Publication No. WO2017 / 145984

  As described above, recently, various IoT devices such as home appliances and automobile electrical components have been connected to the Internet. In this way, if the IoT device is connected to the Internet and used, it can be controlled from the outside using a smartphone or the like, and the built-in firmware can be updated via the Internet, and various advantages can be obtained. It becomes like this. On the other hand, there is a demerit that connecting to the Internet causes a risk of receiving hacking from the outside.

  Computer devices such as personal computers usually use a method of connecting to the Internet via a router or firewall, and in order to ensure sufficient security, it is necessary to install and use anti-virus software. It is common. However, in the case of IoT devices such as home appliances and automobile electrical components, the configuration of CPUs and memories is poor compared to general computer devices, and no sufficient security measures have been taken. In addition, such IoT devices are often designed to be introduced in a simple manner without going through complicated procedures so that general users without computer knowledge can easily use them.

  For example, in the case of an IoT device such as a surveillance camera intended for personal use, there are many types of devices that are assigned a global IP address and directly connected to the Internet. Such IoT devices have extremely insufficient security measures, and must be defenseless against external hacking attacks. If an IoT device is infected with malware by a cyber attack and turned into a bot, the damage will spread further. Of course, it is preferable to take sufficient security measures for the IoT device as well as a general computer. However, for that purpose, it is necessary to expand the CPU performance and the memory capacity, and the increase in cost is unavoidable.

  Accordingly, an object of the present invention is to provide a network communication system capable of connecting an inexpensive IoT device intended for personal use to the Internet while ensuring sufficient security.

(1) In a network communication system, a first aspect of the present invention provides a plurality of terminal devices that can be connected to each other via a network, a connection mediating device that mediates connection between the plurality of terminal devices, A gateway device including one of them,
Each of the plurality of terminal devices is given a terminal ID for identifying each terminal device, and the connection mediating device uses the terminal ID to communicate with the terminal device serving as the communication source and the terminal serving as the communication destination. Execute processing that mediates the connection with the device,
Each of the plurality of terminal devices
A self-address notifying unit for notifying a connection mediating device of a location address indicating a location on the own network;
A communication request accepting unit that accepts a communication request for another terminal device as a communication destination with self as a communication source,
When the communication request is accepted by the communication request accepting unit, the connection mediation device transmits a connection mediation request including communication destination specifying information for specifying the terminal ID of another terminal device of the communication destination to the connection mediating device. A request department;
In response to the connection mediation request, when a communication destination address indicating the location of another terminal device at the communication destination is returned from the connection mediation device, the communication destination address is accessed via the network. A communication start request unit for making a communication start request;
In response to a communication start request, when a communication start acceptance confirmation is returned from another terminal device at the communication destination, a communication source session that establishes a communication session with another terminal device at the communication destination and starts communication An establishment section;
When a communication start request is made from another terminal device of the communication source to the communication destination itself, a communication start acceptance confirmation is transmitted to the other terminal device of the communication source, and between the other terminal device of the communication source A communication destination session establishment unit that establishes a communication session and starts communication;
Have
Connection mediation device
For each terminal device, an address table storage unit that stores an address table that associates a terminal ID with a location address;
An address table update unit that updates the contents of the address table based on the notification from the self-address notification unit of the terminal device;
When a connection mediation request is transmitted from the connection mediation request unit of the terminal device, the address table is referred to correspond to the terminal ID specified by the communication destination specifying information included in the connection mediation request. A communication address return unit that returns the existing address as a communication address,
Have
The gateway device serves to connect one or a plurality of IoT devices connected to the downstream side to a network connected to the upstream side,
When an external terminal device that is not included in the gateway device communicates with a specific IoT device connected to the downstream side of the gateway device,
The connection mediation request unit of the external terminal device transmits a connection mediation request including communication destination specifying information for identifying the internal terminal device included in the gateway device to the connection mediation device,
The communication start request part of the external terminal device accesses the communication destination address returned in response to the connection mediation request, makes a communication start request,
When the communication source session establishment unit of the external terminal device communicates with the communication destination session establishment unit of the internal terminal device, the internal terminal device and the data addressed to the IoT device to be transmitted to the specific IoT device are specified. Transmitting communication data including device specifying information for specifying the IoT device,
When the gateway device receives the communication data, the gateway device extracts the device identification information and the data addressed to the IoT device from the communication data, and distributes the data addressed to the IoT device to the IoT device identified by the device identification information. It is.

(2) According to a second aspect of the present invention, in the network communication system according to the first aspect described above,
When a specific IoT device communicates with a specific external terminal device,
A specific IoT device, with respect to the communication request reception unit of the internal terminal device, terminal device specifying information for specifying a specific external terminal device, device specifying information for specifying the specific IoT device, and a specific external Send data to the terminal device to be transmitted to the terminal device as a communication request,
The connection mediation request unit of the internal terminal device transmits a connection mediation request including communication destination specifying information whose communication destination is the terminal device specified by the terminal device specifying information to the connection mediating device,
The communication start request unit of the internal terminal device makes a communication start request by accessing the communication destination address returned in response to the connection mediation request,
When communication is performed between the communication source session establishing unit of the internal terminal device and the communication destination session establishing unit of the specific external terminal device, the device specifying information and the terminal are transmitted from the internal terminal device to the specific external terminal device. Communication data including data addressed to the device is transmitted.

(3) According to a third aspect of the present invention, there is provided a network communication system, a plurality of terminal devices that can be connected to each other via a network, a connection mediating device that mediates connection between the plurality of terminal devices, A gateway device including one of them,
Each of the plurality of terminal devices is given a terminal ID for identifying each terminal device, and the connection mediating device uses the terminal ID to communicate with the terminal device serving as the communication source and the terminal serving as the communication destination. Execute processing that mediates the connection with the device,
Each of the plurality of terminal devices
A self-address notifying unit for notifying a connection mediating device of a location address indicating a location on the own network;
A communication request accepting unit that accepts a communication request for another terminal device as a communication destination with self as a communication source,
When the communication request is accepted by the communication request accepting unit, the connection mediation device transmits a connection mediation request including communication destination specifying information for specifying the terminal ID of another terminal device of the communication destination to the connection mediating device. A request department;
When a communication source address indicating the location of another terminal device of the communication source on the network is transmitted from the connection mediating device, access to the communication source address via the network and starting a communication start request A request section;
A communication destination session that establishes a communication session with another terminal device of the communication source and starts communication when a communication start acceptance confirmation is returned from another terminal device of the communication source in response to the communication start request An establishment section;
When a communication start request is issued from another terminal device at the communication destination, the communication start acceptance confirmation is sent to the other terminal device at the communication destination, and between the other terminal devices at the communication destination A communication source session establishment unit that establishes a communication session and starts communication;
Have
Connection mediation device
For each terminal device, an address table storage unit that stores an address table that associates a terminal ID with a location address;
An address table update unit that updates the contents of the address table based on the notification from the self-address notification unit of the terminal device;
When a connection mediation request is transmitted from the connection mediation request unit of the terminal device, the address table is referred to correspond to the terminal ID specified by the communication destination specifying information included in the connection mediation request. A communication source address transmitting unit that transmits, as a communication source address, a location address associated with the terminal ID of the communication source terminal device that has transmitted the connection mediation request,
Have
The gateway device serves to connect one or a plurality of IoT devices connected to the downstream side to a network connected to the upstream side,
When an external terminal device that is not included in the gateway device communicates with a specific IoT device connected to the downstream side of the gateway device,
The connection mediation request unit of the external terminal device transmits a connection mediation request including communication destination specifying information for identifying the internal terminal device included in the gateway device to the connection mediation device,
The communication start request unit of the internal terminal device makes a communication start request by accessing the communication source address transmitted in response to the connection mediation request,
When the communication source session establishment unit of the external terminal device communicates with the communication destination session establishment unit of the internal terminal device, the internal terminal device and the data addressed to the IoT device to be transmitted to the specific IoT device are specified. Transmitting communication data including device specifying information for specifying the IoT device,
When the gateway device receives the communication data, the gateway device extracts the device identification information and the data addressed to the IoT device from the communication data, and distributes the data addressed to the IoT device to the IoT device identified by the device identification information. It is.

(4) A fourth aspect of the present invention is the network communication system according to the third aspect described above,
When a specific IoT device communicates with a specific external terminal device,
A specific IoT device, with respect to the communication request reception unit of the internal terminal device, terminal device specifying information for specifying a specific external terminal device, device specifying information for specifying the specific IoT device, and a specific external Send data to the terminal device to be transmitted to the terminal device as a communication request,
The connection mediation request unit of the internal terminal device transmits a connection mediation request including communication destination specifying information whose communication destination is the terminal device specified by the terminal device specifying information to the connection mediating device,
The communication start request unit of a specific external terminal device makes a communication start request by accessing the communication source address transmitted in response to the connection mediation request,
When communication is performed between the communication source session establishing unit of the internal terminal device and the communication destination session establishing unit of the specific external terminal device, the device specifying information and the terminal are transmitted from the internal terminal device to the specific external terminal device. Communication data including data addressed to the device is transmitted.

(5) According to a fifth aspect of the present invention, in the network communication system according to the first to fourth aspects described above,
The gateway device distributes the IoT device address data to the IoT device specified by the device specification information based on the device specification information and the IoT device address data included in the received communication data.

(6) According to a sixth aspect of the present invention, in the network communication system according to the fifth aspect described above,
In the gateway device, an IoT device registration table in which device specifying information about each IoT device connected downstream is directly or indirectly associated with access method information indicating a method of accessing the IoT device. And store
When the gateway device receives the communication data, it refers to the IoT device registration table, and uses the access method indicated by the access method information corresponding to the device identification information extracted from the received communication data, so that the IoT of the delivery destination The device is accessed, and the data addressed to the IoT device extracted from the received communication data is distributed to the distribution destination IoT device.

(7) According to a seventh aspect of the present invention, in the network communication system according to the sixth aspect described above,
The device identification information stored in the IoT device registration table includes the manufacturer name, product model number, and product number of the IoT device,
The access method information stored in the IoT device registration table includes a communication standard for performing communication with the IoT device and a unique address for performing access according to the communication standard.

(8) An eighth aspect of the present invention is the network communication system according to the first to seventh aspects described above,
When the communication source session establishment unit of the external terminal device communicates with the communication destination session establishment unit of the internal terminal device,
The IoT device is subjected to encryption processing using, as an encryption key, unique data stored in the specific IoT device that is the destination or derived data that is uniquely obtained from the data. Create encrypted data addressed to and send encrypted communication data including encrypted data addressed to the IoT device and device identification information,
When the gateway device receives the encrypted communication data, the gateway device extracts the device specifying information and the encrypted data addressed to the IoT device from the encrypted communication data, and is stored in the IoT device specified by the extracted device specifying information. The data addressed to the IoT device is restored by performing a decryption process using the decrypted data or the derived data uniquely obtained from the data as the decryption key, and the restored data addressed to the IoT device is specified by the extracted device identification information. To be distributed to IoT devices.

(9) A ninth aspect of the present invention is the network communication system according to the first to eighth aspects described above,
When the communication source session establishment unit of the external terminal device communicates with the communication destination session establishment unit of the internal terminal device,
An IP header portion including the IP address of the external terminal device as a transmission source address, an IP header portion including the IP address of the internal terminal device as a transmission destination address, and an IP data portion including IoT device-addressed data or IoT device-addressed encryption data and device identification information Is created by encapsulating the data addressed to the IoT device or the encrypted data addressed to the IoT device in the IP packet, and the IP packet is transmitted as communication data or encrypted communication data. It is a thing.

(10) According to a tenth aspect of the present invention, in the network communication system according to the ninth aspect described above,
The internal terminal device sets a specific port as a valid port, notifies the connection mediation device of the current valid port at a predetermined cycle or when the valid port setting is changed, and Receives only IP packets for which the port number corresponding to the valid port is specified among the IP packets transmitted through the server, and rejects other IP packets.
The connection mediating apparatus performs mediation processing using an address including the port number of the valid port as the communication destination address.

(11) An eleventh aspect of the present invention is the network communication system according to the tenth aspect described above,
The internal terminal device always sets only one port as a valid port.

(12) A twelfth aspect of the present invention is the network communication system according to the second or fourth aspect described above,
When the communication source session establishment unit of the internal terminal device communicates with the communication destination session establishment unit of the external terminal device, the gateway device uses a specific IoT device as a transmission source for the data addressed to the terminal device The encrypted data addressed to the terminal device is created by performing encryption processing using the unique data stored in the data or the derived data uniquely obtained from the data as the encryption key, and the encrypted data addressed to the terminal device and the device identification information And send encrypted communication data containing
When the external terminal device receives the encrypted communication data, it decrypts the unique data or the derived data uniquely obtained from the data with respect to the encrypted data destined for the terminal device included in the encrypted communication data. The data addressed to the terminal device is restored by performing a decryption process used as a key.

(13) A thirteenth aspect of the present invention is the network communication system according to the second, fourth or twelfth aspect described above,
When the communication source session establishment unit of the internal terminal device communicates with the communication destination session establishment unit of the external terminal device,
An IP header portion including the IP address of the internal terminal device as a transmission source address and an IP address of the external terminal device as a transmission destination address, and an IP data portion including data addressed to the terminal device or encrypted data addressed to the terminal device and device specifying information Is created by encapsulating the data addressed to the terminal device or the encrypted data addressed to the terminal device in the IP packet, and the IP packet is transmitted as communication data or encrypted communication data. It is a thing.

(14) A fourteenth aspect of the present invention is the network communication system according to the first to thirteenth aspects described above,
The gateway device includes an internal terminal device, an internal terminal intermediary unit, and N individual communication units that correspond one-to-one to N (N is a natural number) IoT devices connected downstream. And
The individual communication unit has a function of performing mutual communication with a corresponding IoT device based on a predetermined communication standard,
The internal terminal intermediary unit stores an IoT device registration table in which device identification information about each IoT device is associated with an individual communication unit corresponding to the IoT device.
The internal terminal intermediary unit extracts device identification information and IoT device-addressed data or IoT device-addressed encrypted data from communication data or encrypted communication data received by the internal terminal device, and refers to the IoT device registration table Thus, an IoT device obtained by selecting an individual communication unit corresponding to the extracted device specifying information and decrypting the extracted data addressed to the IoT device or the extracted encrypted data addressed to the IoT device with respect to the selected individual communication unit. A process for giving addressed data is performed.

(15) A fifteenth aspect of the present invention is the network communication system according to the fourteenth aspect described above,
The gateway device further has a normal router part,
Usually, the router unit has a routing function for connecting the IoT device connected to the downstream side to the network connected to the upstream side,
The internal terminal device only performs communication via mediation by the connection mediation device,
Usually the router part
(a) Ascending communication from IoT device to network,
(b) Out of downstream communications from the network to the IoT device, downstream communications returned as a response to the upstream communications,
(c) Out of downstream communications from the network to the IoT device, downstream communications other than (b) above,
Of the three types of communications, the communications of (a) and (b) are executed and the communications of (c) are rejected.

  (16) A sixteenth aspect of the present invention relates to a gateway device in the network communication system according to the first to fifteenth aspects described above.

  (17) In a seventeenth aspect of the present invention, the network communication system according to the first to fifteenth aspects described above is configured by incorporating a program into a computer.

  In the network communication system according to the present invention, the connection mediating device performs mediation processing up to establishment of a communication session between both terminal devices. Moreover, one terminal device is incorporated in the gateway device, and individual IoT devices are connected to the downstream side of the gateway device. When data is transmitted to a specific IoT device, the data is first transmitted to the gateway device via mediation by the connection mediating device, and then the data is transmitted from the gateway device to the specific IoT device. The process of delivering is performed. As described above, since the data addressed to the IoT device is transmitted through mediation by the connection mediating device and the gateway device, it is possible to prevent the IoT device from being hacked from the outside, and it is sufficient for each IoT device itself. Even if no security measures are taken, individual IoT devices can be connected to the Internet while ensuring sufficient security.

It is a block diagram which shows the whole structure of the network communication system which concerns on 1st Embodiment of a prior invention basic invention. It is a block diagram which shows the detailed structure of the terminal device of the network communication system shown in FIG. It is a block diagram which shows the function of the self-address notification part 250 in the terminal device shown in FIG. In the network communication system shown in FIG. 1, it is a block diagram which shows the procedure of communication session establishment between the communication origin terminal device 200A and the communication destination terminal device 200B. 5 is a flowchart for explaining a communication session establishment procedure shown in the block diagram of FIG. 4 in time series. It is a block diagram which shows the whole structure of the network communication system which concerns on 2nd Embodiment of prior application basic invention. It is a block diagram which shows the detailed structure of the terminal device of the network communication system shown in FIG. FIG. 7 is a block diagram showing a procedure for establishing a communication session between a communication source terminal device 400B and a communication destination terminal device 400A in the network communication system shown in FIG. It is a flowchart explaining the communication session establishment procedure shown by the block diagram of FIG. 8 in time series. FIG. 7 is a diagram showing a first modification of the address table shown in FIG. 1 or FIG. 6. FIG. 7 is a diagram showing a second modification of the address table shown in FIG. 1 or FIG. 6. FIG. 10 is a diagram showing a third modification of the address table shown in FIG. 1 or FIG. 6. In the network communication system shown in FIG. 1, it is a block diagram which shows the modification of the procedure of communication session establishment between the communication origin terminal device 200A and the communication destination terminal device 200B. FIG. 7 is a block diagram showing a modified example of a procedure for establishing a communication session between a communication source terminal device 400B and a communication destination terminal device 400A in the network communication system shown in FIG. It is a block diagram which shows embodiment of the prior invention basic invention in the case of connecting a terminal device to the network N via a router. In the embodiment shown in FIG. 15, it is a figure which shows the example of an address table in the case of using the information which added the port number to the IP address as a location address. It is a table | surface which shows the notification timing of the self address in the case of comprising the terminal device based on a prior invention basic invention using a communication application program. 1 is a block diagram showing an overall configuration of an embodiment using VPN in a network communication system according to a basic invention of a prior application. FIG. It is a figure which shows the principle of VPN communication in embodiment shown in FIG. It is a figure which shows the example of the address table which added the VIP address for using in embodiment shown in FIG. It is a block diagram which shows the specific example which connected the IoT apparatus assumed for personal use to the internet. 1 is a block diagram showing an overall configuration of a network communication system according to a basic embodiment of the present invention. FIG. 23 is a diagram illustrating a configuration example of communication data transmitted from a specific external terminal device to a specific IoT device in the network communication system illustrated in FIG. 22. It is a figure which shows the specific example of the IoT apparatus registration table stored in the gateway apparatus GW shown in FIG. FIG. 23 is a block diagram showing a basic principle for encrypting communication between an external terminal device and an internal terminal device in the network communication system shown in FIG. 22. It is a figure which shows the structural example of the encryption communication data used when encrypting based on the basic principle shown in FIG. FIG. 23 is a diagram illustrating a configuration example of communication data used when information is transmitted from a specific IoT device to a specific external terminal device in the network communication system illustrated in FIG. 22. FIG. 23 is a diagram illustrating a configuration example of encrypted communication data used when transmitting information from a specific IoT device to a specific external terminal device by applying an encryption method in the network communication system illustrated in FIG. 22. It is a block diagram which shows the specific structural example of the gateway apparatus GW shown in FIG. It is a block diagram which shows the specific structure of the apparatus which concerns on the modification of gateway apparatus GW shown in FIG.

  Hereinafter, the present invention will be described based on the illustrated embodiments. Note that the embodiment described here is described in International Application PCT / JP2017 / 006131 (International Publication No. WO2017 / 145984: hereinafter referred to as the prior international application) with priority claim based on PCT / JP2016 / 055960. The present invention relates to an invention using the invention (hereinafter referred to as the prior invention basic invention). Therefore, in the following §1 to §4, first, the prior invention basic invention will be described, and in §5 and after, embodiments of the present invention using this prior application basic invention will be described. Accordingly, the contents described in the following §1 to §4 (contents shown in FIGS. 1 to 20) are substantially the same as the embodiment described in International Publication No. WO2017 / 145984 related to the basic invention of the prior application. It is.

<<< §1. First embodiment of basic invention of prior application >>>
<1-1. Configuration of First Embodiment of Basic Invention of Prior Application>
FIG. 1 is a block diagram showing the overall configuration of a network communication system according to a first embodiment of the basic invention of the prior application. As shown in the figure, this network communication system is composed of a connection mediating device 100 and a plurality of terminal devices 200A to 200D, all of which are connected to each other via a network N (in this example, the Internet). Is possible.

  In the figure, for convenience of explanation, an example using four terminal devices 200A to 200D is shown, but in practice, a larger number of terminal devices are generally used. Each of the terminal devices 200A to 200D is the same device having a common configuration. Therefore, here, when referring to this common terminal device, reference numeral 200 is used, and when it is necessary to distinguish from each other, AD is added to the end of the reference numeral. The same applies to the reference numerals indicating the internal components of the terminal device 200.

  After all, this network communication system is a system including a plurality of terminal devices 200A to 200D that can be connected to each other via the network N and a connection mediating device 100 that mediates the connection between the plurality of terminal devices. become. As the terminal device 200, various electronic devices having a function of connecting to the network N and performing communication, such as a personal computer, a mobile phone, and a tablet terminal, can be used. On the other hand, the connection mediating apparatus 100 is configured by a server computer that receives access from these terminal apparatuses 200A to 200D via the network N.

  Each of the terminal devices 200A to 200D is assigned a terminal ID for identifying each terminal device, and the connection mediating device 100 communicates with the terminal device serving as a communication source using the terminal ID. A process that mediates the connection with the previous terminal device is executed. Here, as shown in the drawing, terminal IDs “0010”, “0020”, “0030”, and “0040” are assigned to the terminal devices 200A, 200B, 200C, and 200D, respectively.

  In implementing the basic invention of the prior application, the terminal ID may be any information as long as it can identify individual terminal devices. In the illustrated example, since only four terminal devices are used, it is sufficient to use a four-digit number such as “0010” as the terminal ID, but in order to identify each terminal device from each other, Since it is necessary to use a unique ID, it is preferable to use a number having a larger number of digits or a combination of a number and an alphabet in practice. Specifically, the serial number of the CPU built into each terminal device, the MAC address assigned to the communication interface, the phone number or the SIM card serial number when a mobile phone is used as the terminal device, the terminal ID Can be used.

  Each of the terminal devices 200A to 200D is given a location address indicating the location on its own network. In the case of the illustrated example, the location addresses AD1, AD2, AD3, and AD4 are assigned to the terminal devices 200A, 200B, 200C, and 200D, respectively. As the location address, any address may be used as long as the location of the terminal device can be uniquely determined on the network. As in the illustrated example, when the Internet is used as the network N and IP is used as the communication protocol, a global IP address or NAT-ID is used as a location address indicating the location of each terminal device 200 on the network N. It is preferable to use it.

  The terminal ID is information necessary for mutually identifying individual terminal devices, whereas the location address is information necessary for accessing the individual terminal devices via the network N. In addition, in many terminal apparatuses, the location address is not always constant and changes every moment. For example, in the case of a portable terminal device such as a mobile phone or a mobile personal computer, the base station as a communication partner changes with movement, so the location address also changes with time. Also, in the case of a fixed-point terminal device such as a desktop personal computer, since the IP address assigned by the provider is updated, the location address generally changes with time.

  As will be described later, the terminal device 200 used in the prior invention basic invention has a function of notifying the connection mediating device 100 of the location address indicating the location on its own network via the network N. For this reason, the connection mediating apparatus 100 can always grasp the latest addresses of the terminal apparatuses 200A to 200D, and can access the terminal apparatuses 200A to 200D as necessary.

  As illustrated, the connection mediating apparatus 100 is provided with an address table storage unit 110, an address table update unit 120, and a communication destination address reply unit 130. As described above, the connection mediating apparatus 100 is actually configured by a computer such as a server computer. Therefore, each component shown as an individual block in the figure is actually constructed by incorporating a dedicated program into the computer.

  The address table storage unit 110 stores an address table T in which each terminal device 200A to 200D is associated with a terminal ID and a location address. The address table update unit 120 stores each terminal device 200A to 200D. Based on the notification from, the contents of this address table T are updated. In addition, when there is a connection mediation request from each of the terminal devices 200 </ b> A to 200 </ b> D, the communication destination address reply unit 130 performs processing for returning the communication destination address by referring to the address table T.

  In the figure, as the address table T, information indicating the correspondence between the terminal ID and the location address is stored for each of the four terminal devices 200A to 200D. Specifically, terminal ID “0010” is associated with location address “AD1” for terminal device 200A, and terminal ID “0020” is associated with location address “AD2” for terminal device 200B. The terminal ID “0030” and the location address “AD3” are associated with the device 200C, and the terminal ID “0040” and the location address “AD4” are associated with the terminal device 200D.

  Next, a detailed configuration of the terminal device 200 and specific processing operations of individual components will be described with reference to FIG. As illustrated, the terminal device 200 includes a connection mediation request unit 210, a communication request reception unit 220, a communication destination session establishment unit 230, a communication start request unit 240, a self address notification unit 250, and a communication source session establishment unit 260. ing.

  This terminal device 200 is also actually constituted by various computers (including devices such as mobile phones), and each component shown as individual blocks in the figure is actually a program dedicated to the computer. It is built by incorporating. In addition, the actual terminal device 200 incorporates various other components. For example, if the terminal device 200 is a smartphone, components having various processing functions are added by incorporating various application programs. Here, the configuration directly related to the prior invention basic invention Only the elements are shown as blocks in the figure, and descriptions of the other components are omitted. Of course, the terminal device 200 also includes components such as an input interface for inputting instructions and characters from the user and a display for presenting information to the user. However, description of these components is also omitted. To do.

  After all, in FIG. 2, the components depicted as six blocks in the terminal device 200 are essential functional elements in the terminal device 200 according to the prior invention basic invention. In this block diagram, three arrows, a thick line arrow, a thin line arrow, and a white arrow, are used as arrows indicating the flow of signals between the blocks. Here, a thick line arrow indicates a signal flow before establishment of a communication session exchanged between the terminal device 200 and the connection mediating apparatus 100, and a thin line arrow indicates exchange between the pair of terminal devices 200. The flow of signals before establishing a communication session is shown. White arrows indicate the flow of signals after the communication session is established, which is exchanged between the pair of terminal devices 200.

  In FIG. 2, the six components in the terminal device 200 are drawn using three types of blocks, an ellipse, a rectangle, and a double rectangle, but this shows the division of roles among the components. It is convenient. Specifically, the constituent elements indicated by the elliptic blocks are constituent elements for the terminal device 200 to execute the “address notification” process, and the constituent elements indicated by the rectangular blocks are the terminal elements 200. Is a component that executes a process necessary when it functions as a “communication source”, and a component indicated by a double rectangular block is a process that is necessary when the terminal device 200 functions as a “communication destination” Is a component that executes

  In the present application, the terms “communication source” and “communication destination” are terms used for distinguishing between two terminal devices when they communicate with each other, and spontaneously start communication. The side that performs processing for this purpose is called the “communication source”, and the side that performs the processing necessary to communicate with the “communication source” is called the “communication destination” in response to the action from this “communication source”. It is out. For example, when two terminal devices are used as telephones, the calling device is the “communication source” and the called device is the “communication destination”. The “communication source” terminal device designates a specific “communication destination” and performs processing for starting communication spontaneously.

  Of course, the terminal device 200 becomes a “communication source” or a “communication destination”. When “communication source” is selected, processing by the components indicated by the rectangular blocks in FIG. 2 is performed, and when “communication destination” is indicated, the components indicated by the double rectangular blocks in FIG. Is processed. Hereinafter, the functions of the six components of the terminal device 200 will be described in order.

  As described above, the self-address notifying unit 250 indicated by the elliptic block is a component for executing the process of “address notification”, and the location address indicating the location on the own network is represented as a connection mediator. A process of notifying the apparatus 100 is executed. If an IP address is used as the location address, the self-address notifying unit 250 performs a process of notifying the connection mediating apparatus 100 of the IP address assigned to it at present through the network N.

  Usually, since a predetermined global IP address is assigned by an Internet provider to the terminal device 200 that can be connected to the Internet, the self-address notification unit 250 connects the global IP address assigned to the terminal device 200 as a location address. What is necessary is just to notify with respect to the mediation apparatus 100. FIG. Further, when a private IP address is assigned using the NAT function of the router, the connection mediating apparatus 100 may be notified of the NAT-ID as a location address. When notifying the location address, the terminal ID is transmitted simultaneously.

  The address table update unit 120 shown in FIG. 1 updates the address table T upon receiving such notification. For example, when the terminal ID “0010” and the location address “AD1” are notified from the terminal device 200A to the connection mediating device 100, the address table update unit 120 has the terminal ID “0010” and the location address “AD1”. Are stored in the address table T in association with each other.

  As described above, in the case of the general terminal device 200, the location address changes with time. Therefore, in practice, it is preferable that the self-address notifying unit 250 has a function of notifying the current address of the current terminal (terminal device 200) repeatedly at a predetermined cycle. For example, if the self-address notification unit 250 repeatedly notifies every other minute, the address table T is updated to the latest information every one minute.

  Alternatively, the self-address notifying unit 250 may have a function of notifying the current location address when the location address of itself (the terminal device 200) is changed. That is, when the location address is assigned for the first time, the location address is notified as an initial address, and thereafter, a new location address is notified every time the location address is changed. Of course, the operation of repeatedly notifying at a predetermined cycle and the operation of notifying when the location address is changed may be combined.

  Next, the four components shown by the rectangular blocks in FIG. 2 will be described. As described above, these four components execute processing necessary when the terminal device 200 functions as a “communication source”.

  First, the communication request accepting unit 220 performs a process of accepting a communication request to another terminal device as a communication destination, using itself as a communication source. For example, when a user of the terminal device 200 (communication source) wants to make a call to a specific partner, a communication request is made to communicate with another terminal device (communication destination) possessed by the partner. become. This communication request is given as, for example, a user operation input (for example, an operation on a touch panel) via an input interface (not shown), and includes some information for specifying the partner terminal device. .

  When the communication request is received by the communication request receiving unit 220, the connection mediation request unit 210 provides communication destination specifying information for specifying the terminal ID of another terminal device that is the communication destination to the connection mediating device 100. Send connection brokerage request including. Here, the communication destination specifying information included in the connection mediation request may be the terminal ID of another terminal device that is the communication destination, or may be other information that can specify the terminal ID. No (details are described in §3-1).

  Thus, the connection mediation request transmitted from the connection mediation request unit 210 is transmitted to the connection mediation device 100 via the network N (as described above, the bold arrows in the figure indicate the terminal device 200 and the connection mediation device 100). Shows the signal flow before and after the communication session is established). Then, the connection mediating apparatus 100 returns a communication destination address indicating the location of another terminal device as a communication destination on the network, as indicated by a thick arrow in the figure. This is due to the function of the communication destination address reply unit 130 shown in FIG.

  That is, the communication destination address reply unit 130 refers to the address table T when the connection mediation request is transmitted from the connection mediation request unit 210 of the terminal device 200, and the communication destination included in the connection mediation request. A process of returning a location address associated with the terminal ID specified by the specific information as a communication destination address is performed. Of course, the destination of the reply is the terminal device 200 that has made the connection mediation request. In short, when there is a connection mediation request specifying the communication destination from the communication source terminal device, the communication destination address reply unit 130 searches the current address of the communication destination using the address table T, A process of returning to the communication source terminal device is performed.

  As described above, when a connection mediation request is made by the connection mediation request unit 210, the connection mediation device 100 returns a communication destination address indicating the location of another terminal device of the communication destination on the network. The communication destination address returned in this way is received by the communication start request unit 240. The communication start request unit 240 makes a communication start request by accessing the communication destination address via the network N. As indicated by the thin line arrows in the figure, this communication start request is a signal addressed from one terminal device 200 (communication source) to another terminal device 200 (communication destination).

  In this way, when the communication start request unit 240 transmits a communication start request to another terminal device that is the communication destination, the communication start acceptance is received from the other terminal device that is the communication destination according to the communication start request. Confirmation is replied (thin line arrow on the right side of the figure: this reply process will be described later as a process of the communication destination session establishment unit 230 of another terminal device of the communication destination). The communication start acceptance confirmation sent back in this way is received by the communication source session establishment unit 260. Upon receiving this communication start acceptance confirmation, the communication source session establishing unit 260 establishes a communication session with another terminal device of the communication destination and starts communication. The white arrow drawn on the right end of FIG. 2 indicates the flow of signals (communication packets) between both terminals after the communication session is established in this way.

  The four constituent elements shown by the rectangular blocks in FIG. 2, that is, the constituent elements that execute processing when the terminal device 200 functions as the “communication source” has been described. Next, FIG. The components shown by the double rectangular blocks, that is, the components that execute processing when the terminal device 200 functions as a “communication destination” will be described.

  In FIG. 2, a component indicated by a double rectangular block is a communication destination session establishment unit 230. This communication destination session establishment unit 230, when a communication start request is made from another terminal device that is the communication source (downward thin line arrow on the left side of the figure), to another terminal device that is the communication source. A communication start acceptance confirmation is transmitted (upward thin line arrow on the left side of the figure), a communication session is established with another terminal device of the communication source, and communication is started. A white arrow drawn at the left end of FIG. 2 indicates a flow of signals (communication packets) between both terminals after the communication session is established in this way.

  Eventually, communication after establishment of the communication session between the communication source terminal device and the communication destination terminal device is performed between the communication source session establishment unit 260 of the communication source terminal device and the communication destination session establishment unit 230 of the communication destination terminal device. Will be done. In other words, the white arrow at the right end in FIG. 2 is connected to the white arrow at the left end in FIG.

<1-2. Specific Communication Procedure in First Embodiment>
So far, each component and function of the connection mediating device 100 and the terminal device 200 which are components of the network communication system according to the first embodiment of the basic invention of the prior application will be described with reference to FIG. 1 and FIG. did. Here, a communication procedure in the network communication system according to the first embodiment will be described based on a specific example.

  FIG. 3 is a block diagram illustrating functions of the self-address notifying unit 250 in the terminal device illustrated in FIG. The connection mediation device 100 is shown in the upper part of the figure, and two sets of terminal devices 200A and 200B are shown in the lower part of the figure. Here, although illustration of the terminal devices 200C and 200D is omitted, the function of the self-address notification unit 250 is the same. As described above, the exchange of information between the connection mediating apparatus 100 and each of the terminal apparatuses 200A and 200B (indicated by a thick arrow) is actually performed via the network N, but here, for convenience of explanation. Illustration of the network N is omitted.

  The terminal devices 200A and 200B shown in FIG. 3 have six components as with the terminal device 200 shown in FIG. That is, the terminal device 200A includes the components 210A to 260A, and the terminal device 200B includes the components 210B to 260B. These components are the same as the components 210 to 260 illustrated in FIG. (A and B at the end of the code are given to distinguish which terminal device is a component). Since FIG. 3 is a diagram for explaining the self-address notification function of the terminal devices 200A and 200B, the blocks of the constituent elements other than the self-address notification units 250A and 250B are indicated by broken lines.

  The self-address notifying units 250A and 250B perform a process of notifying the address table update unit 120 in the connection mediating apparatus 100 of the location address indicating the location on its own network. FIG. 3 shows an example in which data “0010: AD1” is transmitted as a notification from the self-address notification unit 250A to the address table update unit 120. ”Indicates that the current location address“ AD1 ”is being transmitted. Similarly, an example in which data “0020: AD2” is transmitted as a notification from the self-address notifying unit 250B to the address table updating unit 120 is shown together with its own terminal ID “0020”. This indicates that the current location address “AD2” is being transmitted.

  The address table update unit 120 that has received such notification from the self-address notification units 250A and 250B of the terminal devices 200A and 200B performs a process of updating the contents of the address table T based on the notification. As already described in §1-1. In addition, as described in §1-1, the self-address notifying units 250A and 250B perform the process of notifying the current location address repeatedly at a predetermined cycle or when the location address is changed. is there.

  As described above, the location address notification process performed by the self-address notification unit 250 is not a direct process for starting communication between terminal devices, but a preparation process for enabling communication to be started anytime. Can do. By performing this notification processing, the address table T in the connection mediating apparatus 100 can be kept up-to-date, and the connection mediating apparatus 100 can be used when communication between specific terminal devices actually needs to be performed. The correct mediation process by can be realized.

  Next, a processing procedure when actually starting communication between specific terminal devices will be described. FIG. 4 is a block diagram showing a procedure for establishing a communication session between the communication source terminal apparatus 200A and the communication destination terminal apparatus 200B in the network communication system shown in FIG. Also in FIG. 4, the connection mediating apparatus 100 is shown in the upper part of the figure, and two sets of terminal apparatuses 200A and 200B are shown in the lower part of the figure. Also here, the exchange of information between the connection mediating apparatus 100 and the terminal apparatus 200A (indicated by a thick line arrow) and the exchange of information between the terminal apparatuses 200A and 200B (indicated by a thin line arrow) actually involve the network N. The network N is not shown for convenience of explanation.

  Here, for convenience of explanation, a procedure in the case where the terminal device 200A is a communication source and the terminal device 200B is a communication destination will be described. For this reason, in FIG. 4, as for the components in the communication source terminal device 200A, only the components that execute processing necessary as the communication source (components of rectangular blocks) are indicated by solid lines, and in the communication destination terminal device 200B Regarding the constituent elements, only the constituent elements (the constituent elements of the double rectangular block) that execute processing necessary as a communication destination are indicated by solid lines, and the blocks of the other constituent elements are indicated by broken lines.

  On the other hand, FIG. 5 is a flowchart for explaining the communication session establishment procedure shown in the block diagram of FIG. 4 in time series. Hereinafter, a specific communication procedure in the first embodiment will be described according to the flowchart of FIG. 5 with reference to the block diagram of FIG. In the block diagram of FIG. 4, reference numerals S1 to S7 attached to the arrows correspond to the steps S1 to S7 in the flowchart of FIG. Conversely, in each step of the flowchart of FIG. 5, the reference numerals shown in parentheses correspond to specific blocks in the block diagram of FIG. 4 and indicate specific components related to the contents of the steps. Is.

  First, in step S1, communication request acceptance processing is performed. This is a process performed by the communication request accepting unit 220A shown in FIG. 4. For example, when the user A of the communication source terminal device 200A wants to call the user B of the communication destination terminal device 200B, It is a process performed based on the operation input of the user A. For example, when each of the terminal devices 200A and 200B is a mobile phone and each phone number is used as a terminal ID, the user A gives the terminal ID (phone number) of the terminal device 200B to the terminal device 200A. A communication request S1 with an input operation may be performed. That is, the communication request accepting unit 220A of the terminal device 200A performs a process of accepting a communication request S1 for another terminal device 200B that is a communication destination using itself as a communication source.

  Note that the communication request accepting unit 220A accepts the communication request S1 not necessarily when the user A performs an operation input for making a call. For example, when the users A and B are playing a communication battle type game, the communication request S1 is given to the communication request receiving unit 220A from the application program for the game. Alternatively, if the terminal devices 200A and 200B are personal computers that perform some business processing, and the business processing application program incorporated in the personal computer 200A automatically reports to the personal computer 200B, the application program The communication request S1 is given to the communication request receiving unit 220A. As described above, the communication request in the basic invention of the prior application is not necessarily given by the user, but may be given by a program incorporated in the terminal device.

  Thus, when a communication request is accepted in step S1, a connection mediation request is made in subsequent step S2. This is a process performed by the connection mediation request unit 210A shown in FIG. 4, and as described above, the communication destination for specifying the terminal ID of another terminal device 200B as the communication destination for the connection mediation device 100. This is a process of transmitting a connection mediation request S2 including specific information.

  In general, when information is sent and received between two parties connected via a network, the information transmission side transmits its address to the reception side, and the reception side returns an acknowledge signal to the transmission side address. Perform the process. Therefore, when transmitting the connection mediation request S2 from the connection mediation request unit 210A, the own location address “AD1” is transmitted to the connection mediation device 100 side. A reply process in step S4, which will be described later, is performed to this location address “AD1”.

  Thus, when the connection mediation request is transmitted from the connection mediation request unit 210A of the communication source terminal device 200A to the connection mediation device 100, in step S3, the communication destination address reply unit 130 that has received this connection mediation request With reference to the address table stored in the table storage unit 110, it is associated with the terminal ID (in this example, “0020”) specified by the communication destination specifying information included in the connection mediation request. The location address is recognized as the communication destination address. For example, if the address table T at that time is as shown in FIG. 1, the address “AD2” associated with the terminal ID “0020” is recognized as the communication destination address.

  Therefore, in step S4, the communication destination address reply unit 130 performs a process of returning the communication destination address “AD2” recognized in step S3. Of course, the reply partner is the communication source terminal device 200A that made the connection mediation request in step S2. As described above, since the connection mediation request S2 includes information on the location address “AD1” of the communication source terminal device 200A, the communication destination address reply unit 130 sends the communication destination address to the location address “AD1”. “AD2” can be returned.

  Thus, when the communication destination address reply S4 (information for transmitting the communication destination address “AD2”) is transmitted from the communication destination address reply unit 130, the communication destination address reply S4 is received by the communication start request unit 240A. . Eventually, when the communication source terminal device 200A makes a connection mediation request S2 to the connection mediation device 100, the location of the communication destination terminal device 200B on the network is sent from the connection mediation device 100 in response to the connection mediation request S2. The communication destination address “AD2” indicating “” is returned. Since the address table T prepared in the connection mediating apparatus 100 is always updated to the latest state, the returned communication destination address “AD2” is the latest location address of the communication destination terminal apparatus 200B. Become.

  Therefore, the communication start request unit 240A that has acquired the communication destination address “AD2” by the communication destination address reply S4 makes a communication start request S5 to the communication destination terminal device 200B in step S5. That is, access is made to the communication destination address “AD2” via the network N, and a communication start request is transmitted to the other party. At this time, its own address (communication source address “AD1”) is also transmitted.

  The communication start request S5 made to the communication destination address “AD2” is received by the communication destination session establishment unit 230B of the communication destination terminal device 200B. When communication start request S5 is made from communication source terminal device 200A as the communication destination, communication destination session establishment unit 230B first starts communication source terminal device 200A via network N in step S6. To the communication start acceptance confirmation S6. In subsequent step S7, a communication session is established with communication source terminal device 200A, and communication S7 is started.

  On the other hand, the communication start acceptance confirmation S6 transmitted to the communication source terminal device 200A is received by the communication source session establishment unit 260A. In step S7, the communication source session establishment unit 260A that has received the communication start acceptance confirmation S6 establishes a communication session with the communication destination terminal device 200B and starts communication S7. In short, on the communication source terminal device 200A side, when a communication start acceptance confirmation S6 is returned from the communication destination terminal device 200B in response to the communication start request S5, a communication session is established with the communication destination terminal device 200B. Thus, processing for starting communication is performed.

  Thus, a communication session is established between the communication source terminal device 200A and the communication destination terminal device 200B, and communication S7 is performed between the two. In the flowchart shown in FIG. 5, the processes performed by the connection mediating apparatus 100 are only the address table reference process in step S3 and the communication destination address return process in step S4. That is, the mediation process performed by the connection mediating apparatus 100 receives the connection mediation request S2 from the communication source terminal apparatus 200A, refers to the address table T (step S3), and uses the obtained communication destination address as the communication source terminal apparatus 200A. Is simply returned (step S4). The connection mediating apparatus 100 simply performs such mediation processing, whereby a communication session is established between the communication source terminal apparatus 200A and the communication destination terminal apparatus 200B, and communication between the two starts.

  Thus, in the network communication system according to the first embodiment of the prior invention basic invention, the processing load on the connection mediating apparatus 100 is extremely light. As described above, in a system that performs connection mediation processing between both terminals using SIP, the processing load is reduced compared to conventional relay processing, but a session is established between both terminals. It is necessary to be involved until the request is made, and when brokering requests from a large number of terminal devices are concentrated, the processing load becomes considerably heavy. On the other hand, in the case of the system according to the first embodiment of the basic invention of the prior application, the connection mediating apparatus 100 does not need to be involved until a communication session is established between both terminals. It suffices to perform processing for transmitting the communication destination address. For this reason, it becomes possible to reduce the processing load at the time of mediating connection between a pair of terminal devices.

  As described above, in the network communication system according to the first embodiment of the basic invention of the prior application, since the connection mediating apparatus 100 is not involved until the communication session is established, the connection mediating apparatus 100 establishes a communication session between both terminal apparatuses. It is impossible to grasp whether or not communication is performed without any trouble. Therefore, if necessary, after establishing the communication session, the communication session establishment unit 260A or the communication destination session establishment unit 230B reports to the connection mediating apparatus 100 that the communication session has been established without any problem. Also good.

  In the above-described embodiment, when the communication destination session establishing unit 230B makes a communication start request S5 with itself as the communication destination from the communication source terminal device 200A, in step S6, the communication destination session establishment unit 230B requests the communication source terminal device 200A. However, in some cases, the communication start request S5 may be rejected without being accepted, and the communication start acceptance confirmation may not be transmitted (or the communication start acceptance is confirmed). Instead of confirmation, a communication start rejection notice may be transmitted). In other words, the communication destination session establishment unit 230B has some condition determination function, and when the communication start request S5 is made, the process of transmitting the communication start acceptance confirmation is performed only when a predetermined condition is satisfied. You can do it.

  For example, the user B of the communication destination terminal apparatus 200B can set the call rejection setting for the communication destination session establishment unit 230, and the communication is performed only when the condition that “the call rejection setting is not made” is satisfied. The process of transmitting the start acceptance confirmation may be performed. If the communication start request S5 includes some communication source identification information (for example, a terminal ID) for specifying the communication source terminal device 200A, the communication destination session establishment unit 230B causes the communication start request S5 to be included. Depending on the communication source that made the request, it is possible to accept or reject the request.

  For example, if a communication source list (so-called black list) that always rejects the communication start request S5 and a communication source list (so-called white list) that always accepts the communication start request S5 are prepared in the communication destination session establishment unit 230B, The communication destination session establishment unit 230B can determine whether to accept or reject the communication start request S5 by referring to the list.

  Also, as described in §3-3, when adopting a modification that improves security, if there is any security problem in the communication start request S5, an operation of rejecting this may be adopted. Is possible.

<<< §2. Second embodiment of basic invention of prior application >>>
<2-1. Configuration of Second Embodiment of Basic Invention of Prior Application>
Next, a second embodiment of the basic invention of the prior application will be described. FIG. 6 is a block diagram showing the overall configuration of the network communication system according to the second embodiment. As shown in the figure, this network communication system is composed of a connection mediating device 300 and a plurality of terminal devices 400A to 400D, all of which are connected to each other via a network N (in this example, the Internet). Is possible.

  Here, for convenience of explanation, an example using four terminal devices 400A to 400D will be shown, but in practice, a larger number of terminal devices are generally used. Each of the terminal devices 400A to 400D is the same device having a common configuration. When the common terminal device is referred to, the terminal device 400A to 400D is indicated by the reference numeral 400. A to D are attached and shown. The same applies to the reference numerals indicating the internal components of the terminal device 400.

  The network communication system shown in FIG. 6 includes a plurality of terminal devices 400A to 400D that can be connected to each other via a network N, and a connection mediating device 300 that mediates connection between the plurality of terminal devices. It turns out that. As the terminal device 400, various electronic devices having a function of connecting to the network N and performing communication, such as a personal computer, a mobile phone, and a tablet terminal, can be used. Further, the connection mediating apparatus 300 is configured by a server computer that receives access from each of the terminal apparatuses 400A to 400D via the network N.

  Each of the terminal devices 400A to 400D is given a terminal ID for identifying each terminal device, and the connection mediating device 300 communicates with the terminal device serving as a communication source using this terminal ID. A process that mediates the connection with the previous terminal device is executed. As described above, any information may be used as the terminal ID as long as it can identify individual terminal devices. Here, as in the case of the first embodiment described above, terminal IDs “0010”, “0020”, “0030”, and “0040” are assigned to the terminal devices 400A, 400B, 400C, and 400D, respectively. It shall be.

  Each terminal device 400A to 400D is assigned a location address indicating the location on its own network. Here, as in the case of the first embodiment described above, it is assumed that the location addresses AD1, AD2, AD3, and AD4 are assigned to the terminal devices 400A, 400B, 400C, and 400D, respectively. The location address may be any address as long as the location of the terminal device can be uniquely determined on the network, but in practice, a global IP address or NAT-ID may be used. . As described above, this location address changes with time.

  As illustrated, the connection mediating apparatus 300 is provided with an address table storage unit 310, an address table update unit 320, and a communication source address transmission unit 330. This connection mediating apparatus 300 is actually configured by a computer such as a server computer. Therefore, each component shown as an individual block in the figure is actually constructed by incorporating a dedicated program into the computer.

  The address table storage unit 310 is the same component as the address table storage unit 110 shown in FIG. 1 and stores an address table T that associates terminal IDs with location addresses for each of the terminal devices 400A to 400D. Have The address table T shown in FIG. 6 is exactly the same as the address table T shown in FIG. The address table updating unit 320 is the same component as the address table updating unit 120 shown in FIG. 1 and performs processing for updating the contents of the address table T based on notifications from the terminal devices 400A to 400D. As described above, the components 310 and 320 shown in FIG. 6 are substantially the same as the components 110 and 120 shown in FIG.

  On the other hand, the communication source address transmission unit 330 is a component having a function similar to that of the communication destination address reply unit 130 shown in FIG. 1, but performs a slightly different operation. That is, when there is a connection mediation request from each of the terminal devices 400A to 400D, the communication source address transmission unit 330 recognizes the communication destination address by referring to the address table T, and sends the communication source address to the communication destination address. Process to send. A more detailed description of this process will be described later.

  Next, a detailed configuration of the terminal device 400 and specific processing operations of individual components will be described with reference to FIG. As illustrated, the terminal device 400 includes a connection mediation request unit 410, a communication request reception unit 420, a communication source session establishment unit 430, a communication start request unit 440, a self address notification unit 450, and a communication destination session establishment unit 460. ing.

  This terminal device 400 is also actually constituted by various computers (including devices such as mobile phones), and each component shown as individual blocks in the figure is actually a program dedicated to the computer. It is built by incorporating. Of course, the terminal device 400 also incorporates various components and input / output interfaces that are not shown in the drawing as needed, but here, only the components directly related to the basic invention of the prior application are shown in the figure. It will be shown as a block and description of other components will be omitted.

  In FIG. 7, as in FIG. 2, the thick arrows indicating the signal flow between the blocks indicate the signal flow before the establishment of the communication session exchanged between the terminal device 400 and the connection mediating device 300. The thin line arrows indicate the flow of signals exchanged between a pair of terminal devices 400 before establishing a communication session. A white arrow indicates a signal flow after the communication session is established, which is exchanged between the pair of terminal devices 400.

  Similarly to FIG. 2, the components indicated by elliptic blocks in FIG. 7 are components for the terminal device 400 to execute the “address notification” process, and are indicated by rectangular blocks. The element is a component that executes processing necessary when the terminal device 400 functions as a “communication source”. The component indicated by the double rectangular block functions as a “communication destination”. It is a component that executes processing necessary for the case. When the terminal device 400 becomes “communication source”, the processing by the components shown by the rectangular block in FIG. 7 is performed, and when it becomes “communication destination”, it is shown by the double rectangular block in FIG. The process by the component currently performed is performed. Hereinafter, each function of the six components of the terminal device 400 illustrated in FIG. 7 will be described in order.

  First, the self-address notifying unit 450 indicated by an elliptic block is a component for executing the process of “address notification”, and a location address indicating its location on the network is given to the connection mediating apparatus 300. The process of notifying the user is executed. The function of the self-address notifying unit 450 is exactly the same as the function of the self-address notifying unit 250 shown in FIG. The address table updating unit 320 shown in FIG. 6 updates the address table T in response to this notification.

  Next, five components shown in FIG. 7 as rectangular blocks or double rectangular blocks will be described. As described above, the three components indicated by the rectangular blocks perform processing necessary when the terminal device 400 functions as the “communication source”, and the two components indicated by the double rectangular blocks. The element executes processing necessary when the terminal device 400 functions as a “communication destination”.

  First, the communication request accepting unit 420 is a component that performs processing for accepting a communication request to another terminal device as a communication destination with itself as the communication source, and has exactly the same function as the communication request accepting unit 220 shown in FIG. It is a component. Further, when the communication request is accepted by the communication request accepting unit 420, the connection mediation request unit 410 identifies the communication destination for identifying the terminal ID of another terminal device that is the communication destination with respect to the connection mediating device 300. It is a component that transmits a connection mediation request including information, and has the same function as the connection mediation request unit 210 shown in FIG.

  In this way, the connection mediation request transmitted from the connection mediation request unit 410 is transmitted to the connection mediation device 300 via the network N (the bold arrow in the figure indicates the exchange between the terminal device 400 and the connection mediation device 300). Shows the signal flow before the communication session is established). Then, the connection mediating apparatus 300 transmits a communication source address as shown by a thick arrow in the figure. This communication source address is received by the communication start request unit 440.

  It should be noted here that the transmission destination of the communication source address from the connection mediating apparatus 300 is not the communication source terminal apparatus that has issued the connection mediation request, but another terminal apparatus that is the communication destination. That is, in the example shown in FIG. 7, the connection mediation request unit 410 indicated by a rectangular block is a component in the communication source terminal device, whereas the communication start request unit 440 indicated by a double rectangular block is different. This is a component in the communication destination terminal device. Therefore, in the above description, the connection mediation request unit 410 that issues the connection mediation request and the communication start request unit 440 that receives the communication source address transmitted from the connection mediation device 300 in response to the connection mediation request unit 410 are different from each other. Belongs to 400.

  In short, the source address transmission unit 330 shown in FIG. 6 refers to the address table T when a connection mediation request is transmitted from the connection mediation request unit of a certain terminal device 400, and the connection mediation request. The location address associated with the terminal ID of the communication source terminal device that has transmitted the connection mediation request with respect to the location address associated with the terminal ID identified by the communication destination identification information included in Is transmitted as a communication source address.

  In order to clarify the processing function of the communication source address transmission unit 330, here, a specific example (for example, the user B of the terminal device 400B) is assumed in which the terminal device 400B shown in FIG. 6 is the communication source and the terminal device 400A is the communication destination. The above procedure will be described for a case where the caller is the caller and the user A of the terminal device 400A is called as the callee).

  In this case, a connection mediation request specifying the terminal device 400A as a communication destination is transmitted from the communication source terminal device 400B to the connection mediating device 300. The communication source address transmitting unit 330 that has received the connection mediation request recognizes the location address “AD1” of the terminal device 400A designated as the communication destination by referring to the address table T. The communication destination address reply unit 130 in the first embodiment described above performs a process of returning the location address of the communication destination thus recognized to the communication source (transmission source of the connection mediation request). On the other hand, the communication source address transmission unit 330 in the second embodiment shown in FIG. 6 is directed to the recognized communication destination location address “AD1” and the communication source address “AD1” indicating the location of the communication source terminal device 400B. AD2 "(which can be recognized as the address of the transmission source of the connection mediation request).

  Eventually, in the case of the above example, when a connection mediation request is made from the communication terminal device 400B to the connection mediation device 300, the communication mediator address (of the communication source terminal device 400B) The location address “AD2”) is transmitted. This is a significant difference from the first embodiment described above.

  The communication source address thus transmitted is received by the communication start request unit 440 in the communication destination terminal device 400A as shown in FIG. The communication start request unit 440 issues a communication start request to this communication source address (address of the communication source terminal device 400B). That is, when a communication source address indicating the location of another terminal device of the communication source is transmitted from the connection mediating apparatus 300, the communication start request unit 440 transmits the communication source via the network N. The address is accessed and a communication start request is made. As indicated by the thin line arrows in the figure, this communication start request is a signal addressed from one terminal device 400 (communication destination) to another terminal device 400 (communication source).

  On the other hand, a terminal device (terminal device 400B in the above example) that has received a communication start request from another terminal device (terminal device 400A in the above example) as the communication destination sends the communication start request to the communication source session establishing unit. Received at 430 (downward thin line arrow on the left side of the figure). Then, this communication source session establishment unit 430 returns a communication start acceptance confirmation to another terminal device (terminal device 400A in the above example) as the communication destination (upward thin line arrow on the left side of the figure), and the communication A communication session is established with another terminal device and communication is started. The white arrow drawn at the left end of FIG. 7 shows the flow of signals (communication packets) between both terminals after the communication session is established in this way.

  Thus, the communication start acceptance confirmation returned from the communication source terminal device 400B to the communication destination terminal device 400A is received by the communication destination session establishment unit 460 of the communication destination terminal device 400A (thin line arrow on the right side of the figure). Upon receiving this communication start acceptance confirmation, communication destination session establishing section 460 establishes a communication session with another terminal device 400B that is the communication source, and starts communication. A white arrow drawn on the right end of FIG. 7 indicates a flow of signals (communication packets) between both terminals after the communication session is established in this way.

  Thus, communication after establishment of the communication session between the communication source terminal device and the communication destination terminal device is performed between the communication source session establishment unit 430 of the communication source terminal device and the communication destination session establishment unit 460 of the communication destination terminal device. Will be done. In other words, the white arrow at the left end in FIG. 7 is connected to the white arrow at the right end in FIG.

<2-2. Specific Communication Procedure in Second Embodiment>
So far, each component and function of the connection mediating apparatus 300 and the terminal device 400 which are components of the network communication system according to the second embodiment of the basic invention of the prior application will be described with reference to FIGS. did. Here, a communication procedure in the network communication system according to the second embodiment will be described based on a specific example.

  First, the function of the self-address notification unit 450 in the terminal device shown in FIG. 7 is the same as the function of the self-address notification units 250A and 250B described with reference to FIG. To do.

  Therefore, a processing procedure when actually starting communication between specific terminal devices will be described below. FIG. 8 is a block diagram illustrating a procedure for establishing a communication session between the communication source terminal apparatus 400B and the communication destination terminal apparatus 400A in the network communication system illustrated in FIG. In FIG. 8, the connection mediating apparatus 300 is shown in the upper part of the figure, and two sets of terminal apparatuses 400A and 400B are shown in the lower part of the figure. Also here, the exchange of information between the connection mediating apparatus 300 and each of the terminal devices 400A and 400B (indicated by a thick arrow) and the exchange of information between the terminal devices 400A and 400B (indicated by a thin line arrow) are actually performed. Although it is performed via the network N, the network N is not shown for convenience of explanation.

  Further, here, for convenience of explanation, a procedure when the terminal device 400B is a communication source and the terminal device 400A is a communication destination will be described. For this reason, in FIG. 8, as for the components in the communication source terminal device 400B, only the components that execute processing necessary as the communication source (components of rectangular blocks) are indicated by solid lines, and in the communication destination terminal device 400A Regarding the constituent elements, only the constituent elements (the constituent elements of the double rectangular block) that execute processing necessary as a communication destination are indicated by solid lines, and the blocks of the other constituent elements are indicated by broken lines.

  On the other hand, FIG. 9 is a flowchart for explaining the communication session establishment procedure shown in the block diagram of FIG. 8 in time series. Hereinafter, a specific communication procedure in the second embodiment will be described according to the flowchart of FIG. 9 with reference to the block diagram of FIG. In the block diagram of FIG. 8, reference numerals S11 to S17 attached to the arrows correspond to the steps S11 to S17 in the flowchart of FIG. Conversely, in each step of the flowchart of FIG. 9, the reference numerals shown in parentheses correspond to specific blocks in the block diagram of FIG. 8, and indicate specific components related to the contents of the steps. Is.

  First, in step S11, a communication request acceptance process is performed. This is a process of accepting a communication request by the communication request accepting unit 420B shown in FIG. 8 and is the same as the process described in step S1 of FIG. In the subsequent step S12, a connection mediation request S12 is made based on this communication request. This is a process performed by the connection mediation request unit 410B shown in FIG. 8 and is the same as the process described in step S2 of FIG.

  Thus, from the connection mediation request unit 410B of the communication source terminal device 400B to the connection mediation device 300, the connection mediation request S12 (in the illustrated example, the terminal ID “0010” of the communication destination terminal device 400A is included as communication destination specifying information). In step S13, the communication source address transmission unit 330 that has received the connection mediation request S12 refers to the address table stored in the address table storage unit 310, and the connection mediation is performed. The location address associated with the terminal ID (in this example, “0010”) specified by the communication destination specifying information included in the request is recognized as the communication destination address (S13). For example, if the address table T at that time is as shown in FIG. 6, the address “AD1” associated with the terminal ID “0010” is recognized as the communication destination address.

  Therefore, in step S14, the source address reply unit 330 is associated with the terminal ID “0020” of the source terminal device 400B that has transmitted the connection mediation request S12 to the destination address “AD1” recognized in step S13. Is sent as the communication source address (S14).

  As described above, in general, when information is transmitted and received between two parties connected via a network, the information transmitting side transmits its own address to the receiving side, and the receiving side acknowledges to the address of the transmitting side. Process to send back the signal. Therefore, when the communication source address transmission unit 330 receives the connection mediation request S12, the communication source address transmission unit 330 can recognize the location address “AD2” of the terminal device 400B that is the transmission source. In this case, the recognized location address “AD2” may be transmitted as data.

  As described above, when the communication source terminal device 400B makes the connection mediation request S12 to the connection mediation device 300, the connection mediation device 300 sends an address (address) to the communication destination terminal device 400A according to the connection mediation request S12. The communication source address “AD2” indicating the location of the communication source terminal device 400B is transmitted to the location address “AD1” searched in the table T). Since the address table T prepared in the connection mediating apparatus 300 is constantly updated to the latest state, the communication source address transmission S14 is always performed for the latest location address of the communication destination terminal apparatus 400A. Become.

  Thus, when the communication source address transmission unit 330 transmits the communication source address transmission S14 (information that transmits the communication source address “AD2”), the communication source address transmission S14 sends a communication start request of the communication destination terminal device 400A. Received by unit 440A.

  The communication start request unit 440A that has acquired the communication source address “AD2” by the communication source address transmission S14 makes a communication start request S15 to the communication source terminal device 400B in step S15. That is, access is made to the communication source address “AD2” via the network N, and a communication start request is transmitted to the other party. At this time, its own address (communication source address “AD1”) is also transmitted.

  The communication start request S15 made to the communication source address “AD2” is received by the communication source session establishment unit 430B of the communication source terminal device 400B. When the communication source session establishing unit 430B makes a communication start request S15 with the communication source terminal device 400A as its communication source (first device 400B), first, the communication source terminal device 400A first communicates with the communication destination terminal device 400A via the network N in step S16. The communication start acceptance confirmation S16 is transmitted. In subsequent step S17, a communication session is established with communication destination terminal device 400A, and communication S17 is started.

  On the other hand, the communication start acceptance confirmation S16 transmitted to the communication destination terminal device 400A is received by the communication destination session establishment unit 460A. In step S17, the communication destination session establishment unit 460A that has received the communication start acceptance confirmation S16 establishes a communication session with the communication source terminal device 400B and starts communication S17. In short, on the communication destination terminal device 400A side, when the communication start acceptance confirmation S16 is returned from the communication source terminal device 400B in response to the communication start request S15, a communication session is established with the communication source terminal device 400B. Thus, processing for starting communication is performed.

  Thus, a communication session is established between the communication source terminal device 400B and the communication destination terminal device 400A, and communication S17 is performed between the two. In the flowchart shown in FIG. 9, the processes performed by the connection mediating apparatus 300 are only the address table reference process in step S13 and the communication source address transmission process in step S14. That is, the mediation process performed by the connection mediating apparatus 300 receives the connection mediation request S12 from the communication source terminal apparatus 400B, refers to the address table T (step S13), and sends the communication source to the obtained communication destination address. Only the address data is transmitted (step S14). The connection mediating apparatus 300 simply performs such mediation processing, so that a communication session is established between the communication source terminal apparatus 400B and the communication destination terminal apparatus 400A, and communication between the two starts.

  As described above, in the network communication system according to the second embodiment of the basic invention of the prior application, the processing load of the connection mediating apparatus 300 becomes extremely light as in the network communication system according to the first embodiment. As described above, in a system that performs connection mediation processing between both terminals using SIP, the processing load is reduced compared to conventional relay processing, but a session is established between both terminals. It is necessary to be involved until the request is made, and when brokering requests from a large number of terminal devices are concentrated, the processing load becomes considerably heavy. In contrast, in the case of the system according to the second embodiment of the basic invention of the prior application, the connection mediating apparatus 300 does not need to be involved until a communication session is established between both terminals. It suffices to perform processing for transmitting the communication source address. For this reason, it becomes possible to reduce the processing load at the time of mediating connection between a pair of terminal devices.

  As described above, in the network communication system according to the second embodiment of the basic invention of the prior application, since the connection mediating apparatus 300 is not involved until the establishment of the communication session, the connection mediating apparatus 300 establishes a communication session between both terminal apparatuses. It is impossible to grasp whether or not communication is performed without any trouble. Therefore, if necessary, after the communication session is established, the communication session establishment unit 430B or the communication destination session establishment unit 460A reports to the connection mediating apparatus 300 that the communication session has been established without any problem. Also good.

  In the above-described embodiment, when the communication start request unit 440A of the communication destination terminal device 400A receives the communication source address transmission S14 from the connection mediating device 300, the communication start request S15 is automatically issued in step S15. In some cases, the communication start request unit 440A is provided with some condition determination function, and only when the communication source address transmission S14 is received and the predetermined condition is satisfied, the communication start request is issued. S15 may be transmitted. Alternatively, when the predetermined condition is not satisfied, a communication start rejection notification may be transmitted instead of the communication start request S15.

  For example, if a communication source list (so-called black list) that always refuses communication start or a communication source list (so-called white list) that always permits communication start is prepared in the communication start request unit 440A, the communication start request unit 440A. If the communication source address transmitted by the communication source address transmission S14 is listed in the black list by referring to the list, processing for not transmitting the communication start request S15 is performed. An operation of transmitting a communication start rejection notice can be performed. Alternatively, it is possible to perform an operation in which the communication start request S15 is transmitted only when the communication source address is listed on the white list.

  In the above-described embodiment, when the communication source session establishing unit 430B makes a communication start request S15 with the communication source terminal device 400A as a communication source, the communication source session establishment unit 430B requests the communication destination terminal device 400A in step S16. However, in some cases, the communication start request S15 may be rejected without being accepted, and the communication start acceptance confirmation may not be transmitted (or the communication start acceptance is confirmed). Instead of confirmation, a communication start rejection notice may be transmitted).

  For example, as described in §3-4, when adopting a modification that improves security, if there is any security problem in the communication start request S15, an operation of rejecting this may be adopted. Is possible.

<<< §3. Modification of the first and second embodiments of the basic invention of the prior application >>>
Here, some modified examples will be described with respect to the first embodiment of the basic application of the prior application described in §1 and the second embodiment of the basic application of the prior application described in §2.

<3-1. Modification regarding terminal ID>
As described above, the address table T is stored in the address table storage unit 110 in the connection mediating apparatus 100 of FIG. The same applies to the address table storage unit 310 in the connection mediating apparatus 300 of FIG. This address table T is a table in which the terminal ID and the location address are associated with each terminal device, and the communication destination address reply unit 130 or the communication source address transmission unit 330 is included in the received connection mediation request. The address table T is referred to based on the communication destination specifying information, and the location address of the communication destination is acquired.

  For example, in the case of the first embodiment shown in FIG. 4, the connection mediation request S2 includes the terminal ID “0020” of the communication destination terminal device 200B as the communication destination specifying information. By referring to the address table T, the location address “AD2” corresponding to the terminal ID “0020” can be acquired. Similarly, in the case of the second embodiment shown in FIG. 8, the connection mediation request S12 includes the terminal ID “0010” of the communication destination terminal device 400A as communication destination specifying information. By referring to the address table T, the location address “AD1” corresponding to the terminal ID “0010” can be acquired.

  Thus, in the embodiments described so far, the terminal ID of the communication destination terminal device is used as the communication destination specifying information included in the connection mediation request. This terminal ID is information for mutually identifying individual terminal devices. Specifically, the serial number of the CPU built in each terminal device, the MAC address assigned to the communication interface, the mobile phone In the case of a terminal device that functions as a terminal ID, a telephone number, a SIM card serial number, or the like can be used as a terminal ID.

  However, in general, it is difficult for a user to store a terminal ID for another user's terminal device. Therefore, when making a communication request, it is not preferable that the user himself / herself directly input these terminal IDs. Therefore, in practice, when making a communication request, it is preferable to specify a communication destination with a user ID instead of specifying a communication destination with a terminal ID. The terminal ID is an ID for identifying individual terminal devices, whereas the user ID is an ID for identifying individual users. In general, a user name or a nickname can be used as a user ID.

  In order to be able to make a communication request using the user ID instead of the terminal ID, a correspondence table between the user ID and the terminal ID may be prepared in the communication request receiving units 220 and 420. When the user makes a communication request by designating a specific user ID (for example, a user name), the communication request receiving units 220 and 420 use the prepared correspondence table to change the user ID to the terminal ID. It is only necessary to convert the information into the connection mediation request units 210 and 410. Then, the connection mediation request units 210 and 410 can transmit the connection mediation request including the terminal ID. Such a conversion processing function from a user ID (for example, a user name) to a terminal ID (for example, a telephone number) is a well-known function provided as a “telephone number registration function” in a general mobile phone. Detailed description is omitted here.

  As another method for making it possible to use the user ID instead of the terminal ID, a method of preparing a correspondence table between the user ID and the terminal ID on the connection mediating apparatus 100 or 300 side can be adopted. For example, an address table T1 as shown in FIG. 10 is stored in the address table storage units 110 and 310 in place of the address table T shown in FIGS. This address table T1 is a table including information that associates, for each individual terminal device, a user ID that identifies the user of the terminal device and a terminal ID of the terminal device.

  FIG. 10 shows an example in which user names such as “John” and “Mary” are used as user IDs for convenience of explanation, but in practice, individual users recorded in the table can be mutually identified. In this way, the full name of each user is registered as a user ID, and if there is a user with the same surname, a user ID that can be distinguished from each other is registered. Actually, the self-address notification units 250 and 450 of the terminal devices 200 and 400 are provided with a function of reporting such a user ID to the connection mediating devices 100 and 300, and the address table update units 120 and 320 If a function for registering the user ID that has received the report is provided in the address table T1, an address table T1 as shown in FIG. 10 can be prepared.

  If the address table T1 is prepared, it is not necessary for the terminal device serving as the communication source to recognize the terminal ID of the terminal device serving as the communication destination. For example, in the example shown in FIG. 4, when a call is made from the communication source terminal device 200A to the communication destination terminal device 200B, the user A (John) of the communication source terminal device 200A is the user B of the communication destination terminal device 200B. A communication request specifying the user name “Mary” (user ID) as the communication destination may be performed. In this case, instead of the terminal ID “0020”, the connection mediation request S2 including the user ID “Mary” as the communication destination specifying information is transmitted from the connection mediation request unit 210A to the connection mediation apparatus 100.

  The communication destination address reply unit 130 that has received such a connection mediation request S2 refers to the address table T1 shown in FIG. 10, and thereby the terminal ID corresponding to the user name “Mary” included as the communication destination specifying information. “0020” can be recognized, and the location address “AD2” of the communication destination terminal device 200B having the terminal ID “0020” can be recognized.

  FIG. 11 is a diagram illustrating an address table T2 using an account ID instead of a user ID. The user ID is information for specifying individual users, whereas the account ID is information for specifying user accounts established by individual users. For example, in the illustrated example, the account ID “U11111” is an ID indicating a user account opened by the user “John”, and the account ID “U22222” is an ID indicating a user account opened by the user “Mary”. is there. Of course, each user can open multiple accounts if necessary.

  The self-address notifying unit 250, 450 of the terminal device 200, 400 is provided with an application function for opening such an account, and the address table updating unit 120, 320 has a predetermined user account according to the application. If the function for registering the account ID in the address table T2 is provided, an address table T2 as shown in FIG. 11 can be prepared.

  In the example shown in FIG. 4, if the address table T2 as shown in FIG. 11 is prepared in the address table storage unit 110, the connection mediation request unit 210A becomes “U22222” instead of the terminal ID “0020”. A connection mediation request S2 including the account ID as communication destination specifying information may be transmitted to the connection mediation apparatus 100.

  Thus, in the prior application basic invention, the connection mediation request transmitted from the connection mediation request unit includes some “communication destination identification information” that plays a role of identifying the terminal ID of another terminal device that is the communication destination. If it is, it is enough. The “communication destination identification information” may be the terminal ID itself, or may be a user ID or an account ID as in the above example.

  After all, when the modification example described in §3-1 is applied to the first embodiment described in §1, in the configuration shown in FIG. Stores an address table T1 (FIG. 10) or T2 (FIG. 11) that includes information for associating a user ID that identifies a user of the terminal device or an account ID that identifies a user account with the terminal ID of the terminal device. Try to keep it. In addition, the connection mediation request unit 210A transmits a connection mediation request S2 using a user ID that identifies a user of a communication destination terminal device or an account ID that identifies a user account as communication destination specifying information. Then, the communication destination address reply unit 130 refers to the address table T1 or T2 when the connection mediation request S2 is transmitted from the connection mediation request unit 210A, or the user ID included in the connection mediation request S2 or The terminal ID associated with the account ID may be determined, and the process of returning the location address associated with the determined terminal ID as the communication destination address may be performed.

  On the other hand, when the modification described in §3-1 is applied to the second embodiment described in §2, in the configuration illustrated in FIG. 8, the address table storage unit 310 stores each of the individual terminal devices. Stores an address table T1 (FIG. 10) or T2 (FIG. 11) that includes information for associating a user ID that identifies a user of the terminal device or an account ID that identifies a user account with the terminal ID of the terminal device. Try to keep it. Further, the connection mediation request unit 410B transmits a connection mediation request S12 using a user ID for identifying a user of a communication destination terminal device or an account ID for identifying a user account as communication destination specifying information. Then, the communication source address transmission unit 330 refers to the address table T1 or T2 when the connection mediation request S12 is transmitted from the connection mediation request unit 410B, or the user ID included in the connection mediation request S12 or The terminal ID associated with the account ID may be determined, and the process of transmitting the communication source address to the location address associated with the determined terminal ID may be performed.

<3-2. Modification using an alternative terminal>
As described above, there are a wide variety of terminal devices that can be used in the basic invention of the prior application, such as personal computers, mobile phones, and tablet terminals. Recently, it is not uncommon for the same user to use a plurality of terminal devices. Here, in consideration of such a situation, when a call is received for a specific terminal device, a modified example having a mechanism for guiding the call to another terminal device of the same user will be described. .

  When implementing the modification described here, an address table T3 as shown in FIG. 12 is prepared in advance. In the case of this address table T3, terminal IDs and location addresses are registered for each of the four sets of user IDs “John”, “Mary”, “Frank”, and “Susie”. Two terminal IDs “0010” and “0011” are registered, and three terminal IDs “0030”, “0031”, and “0032” are registered for the user ID “Frank”. This is because the user John owns two terminal devices that can be used in this network communication system, and the user Frank owns three terminal devices.

  Here, a plurality of terminal IDs registered in association with the same user ID are grasped as terminal IDs belonging to one group, and one terminal ID belonging to the same group is changed to another one terminal ID. The address table T3 shown in FIG. 12 can be said to be an address table in which one or a plurality of alternative terminal IDs are registered for a specific terminal ID. In short, when multiple terminal IDs are registered with the same user name, it is assumed that these terminal IDs belong to the same group and are handled as mutually recognized as alternative terminal IDs. That's fine.

  For example, in the example shown in FIG. 12, one alternative terminal ID “0011” is registered for the terminal ID “0010”, and conversely, one alternative terminal ID “0010” is registered for the terminal ID “0011”. It will be registered. On the other hand, two alternative terminal IDs “0031” and “0032” are registered for the terminal ID “0030”, and two alternative terminal IDs “0030” and “0032” are registered for the terminal ID “0031”. Therefore, two alternative terminal IDs “0030” and “0031” are registered for the terminal ID “0032”.

  In the system according to the modification described here, by registering such an alternative terminal ID, when a call is made to a terminal device in an inconvenient use state, the call is replaced as an alternative. Can be forwarded to any terminal device.

  For example, the user John owns a first terminal device (terminal ID “0010”) made up of a smartphone and a second terminal device (terminal ID “0011”) made up of a personal computer. Let's assume that the device is also available. However, it is assumed that one day, the first terminal device made up of a smartphone becomes temporarily unavailable due to battery exhaustion. In this case, even if the user Mary makes a communication request with the user's terminal device as the communication source and the user John's smartphone as the communication destination, a normal connection to the user John's smartphone cannot be made.

  In such a system according to the modification described here, in such a case, the connection mediating apparatus can execute a process of performing an alternative connection to the user John's personal computer instead of the user John's smartphone.

  When the modification described in §3-2 is applied to the first embodiment of the basic invention of the prior application described in §1, the following changes may be made to the configuration shown in FIG.

  First, the address table storage unit 110 stores an address table (for example, the address table T3 shown in FIG. 12) in which one or a plurality of alternative terminal IDs are registered for a specific terminal ID. Then, a function for determining whether or not each terminal device is in an inconvenient use state is added to the communication destination address reply unit 130. Specifically, for example, a test access is made to the terminal device to be determined, and if there is a normal reply, it is determined that there is no problem, but if a normal reply is not obtained, it is inconvenient to use. What is necessary is just to judge that it is in a proper state.

  When the connection mediation request S2 is transmitted, the communication destination address reply unit 130 determines whether or not the terminal device to which the original terminal ID specified by the communication destination specifying information is assigned is in an inconvenient use state. Processing to determine is performed. If the terminal device to which the original terminal ID is assigned is in an inconvenient use state, the location address associated with the alternative terminal ID is returned as the communication destination address instead of the original terminal ID. To perform the process.

  For example, in the state where the address table T3 shown in FIG. 12 is prepared, when a connection mediation request including the original terminal ID “0010” (user John's smartphone) is transmitted as the communication destination specifying information, the communication destination address The reply unit 130 first performs a test access to the location address “AD1” corresponding to the terminal ID “0010”, and when there is a normal reply, determines that there is no problem, and follows the location address “AD1” according to a normal procedure. "May be returned as a communication destination address. In this case, the communication source terminal device can communicate with the user John's smartphone to which the original terminal ID “0010” is assigned as the communication destination.

  However, if a normal reply is not obtained for the test access, it is determined that the terminal device (user John's smartphone) to which the original terminal ID “0010” is assigned is in an inconvenient use state. Instead of the terminal ID “0010”, the location address “AD5” associated with the terminal ID “0011” registered as the alternative terminal ID for the terminal ID “0010” in the address table T3 is used as the communication destination address. Do the process of replying. In this case, the communication source terminal device may perform communication using the user John's personal computer with the alternative terminal ID “0011” as a communication destination instead of the user John ’s smartphone with the original terminal ID “0010”. it can.

  On the other hand, when the modification described in §3-2 is applied to the second embodiment of the basic invention of the prior application described in §2, the following changes are made to the configuration shown in FIG. Good.

  First, the address table storage unit 310 stores an address table (for example, the address table T3 shown in FIG. 12) in which one or a plurality of alternative terminal IDs are registered for a specific terminal ID. Then, a function for determining whether or not each terminal device is in an inconvenient use state is added to the communication source address transmission unit 330. Specifically, as described above, test access is made to the terminal device to be determined, and when there is a normal reply, it is determined that there is no problem, but when a normal reply is not obtained May be determined to be in an inconvenient use state.

  When the connection mediation request S12 is transmitted, the communication source address transmission unit 330 determines whether or not the terminal device to which the original terminal ID specified by the communication destination specifying information is assigned is in an inconvenient use state. Processing to determine is performed. If the terminal device to which the original terminal ID is assigned is in an inconvenient state of use, connection mediation is performed for the location address associated with the alternative terminal ID instead of the original terminal ID. A process of transmitting the location address of the communication source terminal device that transmitted the request S12 as the communication source address is performed.

  For example, in the state where the address table T3 shown in FIG. 12 is prepared, when a connection mediation request including the original terminal ID “0010” (user John's smartphone) is transmitted as the communication destination specifying information, the communication source address First, the transmitting unit 330 performs a test access to the location address “AD1” corresponding to the terminal ID “0010”, and determines that there is no problem when there is a normal reply, and the location address “AD1” is determined according to a normal procedure. The communication source address may be transmitted to “ In this case, the communication source terminal device can communicate with the user John's smartphone to which the original terminal ID “0010” is assigned as the communication destination.

  However, if a normal reply is not obtained for the test access, it is determined that the terminal device (user John's smartphone) to which the original terminal ID “0010” is assigned is in an inconvenient use state. The source address addressed to the location address “AD5” associated with the terminal ID “0011” registered as the alternative terminal ID for the terminal ID “0010” in the address table T3 instead of the terminal ID “0010” To send. In this case, the communication source terminal device may perform communication using the user John's personal computer with the alternative terminal ID “0011” as a communication destination instead of the user John ’s smartphone with the original terminal ID “0010”. it can. In addition, like a user Frank shown in FIG. 12, when a plurality of alternative terminal IDs are registered, priorities are determined in advance, and alternative terminal IDs that are actually used may be determined in descending order of priority. .

  In the above-described embodiment, the communication destination address reply unit 130 and the communication source address transmission unit 330 perform the test access to the original communication destination at the time of receiving the connection mediation request, and are in an inconvenient use state. Instead of this, instead of performing periodic test access to individual terminal devices, terminal devices that are in an inconvenient use state are stored in the address table at that time. You may make it record to the effect. In this case, regardless of whether there is a connection mediation request, each terminal device periodically receives a test access and receives a check whether it is in an inconvenient state of use, and the check result is recorded in the address table. Will be. Therefore, when there is an actual connection mediation request, it is possible to determine whether or not the user is in an inconvenient state based on the record in the address table.

  Note that the “unusable state” in this modification does not mean only the “unusable state” such as a state of running out of battery or a state of connection failure to the network. For example, the function of the terminal device is in a state where it can be normally used, but also includes a state where the user thinks that the user does not want to use it arbitrarily and has made such settings. For example, when the user sets “reject incoming call” by his / her own intention, the terminal device enters a “use inconvenient state”. Therefore, in the case of the above example, even if both the smartphone and personal computer possessed by the user John are in a normal operation state, if the user John sets “reject call” to the smartphone, the smartphone It is in an inconvenient use state.

  The setting of “reject call” (setting of “unusable state”) may be recorded only in each terminal device, but may be recorded in an address table in the connection mediating device. . If it is recorded in the address table, it is possible to recognize that it is in an “unusable state” without performing test access to each terminal device.

<3-3. Modification (1) for improving security>
Here, a modification for constructing a network communication system with improved security will be described. Generally, when exchanging information between electronic devices via a network, it is important to ensure the authenticity of the other party. Communication with a partner whose authenticity is not guaranteed may cause a cracker attack, which is a security problem. In the case of the network communication system according to the basic invention of the prior application, communication between each terminal device and the connection mediating device and communication between the communication source terminal device and the communication destination terminal device are indispensable. Ensuring security in communication between devices is important.

  FIG. 13 is a block diagram showing a modified example in which security is improved in the network communication system according to the first embodiment shown in FIG. In this modification, two measures are taken to improve security for the network communication system according to the first embodiment.

  The first countermeasure is the addition of mutual authentication processing. When transmitting and receiving information indicated by the dashed arrows in the figure, mutual authentication processing for confirming the authenticity of the other party is performed between the two. Specifically, first, when transmitting the connection mediation request S2 from the communication source terminal device 200A to the connection mediation device 100, the communication source terminal device 200A and the connection mediation device 100 mutually communicate with each other. Mutual authentication processing is performed to confirm the authenticity of. The arrow indicating the connection mediation request S2 is a broken line, indicating that this mutual authentication process is performed. Therefore, each terminal device 200 and the connection mediating device 100 have such an authentication processing function.

  In the case of the illustrated example, the mutual authentication processing when the connection mediating apparatus 100 performs the communication destination address reply S4 to the communication source terminal apparatus 200A is omitted (the arrow indicating the communication destination address reply S4 is a solid line). Drawn). This is because when the connection mediation request S2 is transmitted, the mutual authentication process between the communication source terminal device 200A and the connection mediation device 100 has already been completed, and the authenticity of the counterpart device has been confirmed. Because. Of course, the mutual authentication process may be executed again when the communication destination address reply S4 is performed.

  In the case of the system shown in FIG. 13, when the communication start terminal device 200A transmits a communication start request S5 to the communication destination terminal device 200B, the communication source terminal device 200A and the communication destination terminal device 200B are also connected. Then, mutual authentication processing is performed to mutually confirm the authenticity of the counterpart devices. The arrow indicating the communication start request S5 is a broken line, indicating that this mutual authentication process is performed. Therefore, each terminal device 200 has such an authentication processing function.

  In the case of the illustrated example, the mutual authentication process when the communication destination terminal device 200B performs the communication start acceptance confirmation S6 to the communication source terminal device 200A is omitted (the arrow indicating the communication start acceptance confirmation S6 is a solid line) Drawn in). This is because when the communication start request S5 is transmitted, the mutual authentication process between the communication source terminal device 200A and the communication destination terminal device 200B has already been completed, and the authenticity of the counterpart device has been confirmed. Because it is. Of course, the mutual authentication process may be executed again when the communication start acceptance confirmation S6 is performed.

  Since various methods are already known as mutual authentication processing for confirming the authenticity of the other party between a pair of devices connected via a network, detailed description thereof is omitted here. In general, mutual authentication processing using the other party's encryption key is often used. For example, in mutual authentication processing using a public key cryptosystem, one device encrypts specific plaintext data using the other device's public key, and transmits the obtained ciphertext data to the other device and receives it. In the other apparatus, it is possible to adopt a processing procedure such as decrypting the ciphertext data using its own encryption key and confirming that the original plaintext data can be restored. If this processing procedure is performed on both sides, it is possible to mutually confirm the authenticity of the other party.

  In addition, when the mutual authentication process between the communication source terminal device 200A and the communication destination terminal device 200B is performed using the respective encryption keys, the two after the communication session is established using the encryption keys. If the communication S7 is performed by encrypted communication, security can be further improved. Specifically, the mutual authentication process when transmitting the communication start request S5 is performed by a process using the encryption key for the communication source terminal apparatus 200A and the encryption key for the communication destination terminal apparatus 200B, and the communication source terminal If the communication S7 after establishment of the communication session between the device 200A and the communication destination terminal device 200B is performed by packet communication in which a packet encrypted using the encryption key used in the mutual authentication process is transmitted and received. Good.

  In the system shown in FIG. 13, the second countermeasure taken to improve security is issuance of a mediation certificate by the connection mediating apparatus 100. In the illustrated example, the connection mediating apparatus 100 plays a role of mediating the connection between the communication source terminal apparatus 200A and the communication destination terminal apparatus 200B. The mediation certificate is a certificate issued by the connection mediating apparatus 100 to prove the fact that “such mediation has been performed”. The communication destination terminal device 200B can confirm that the mediation by the connection mediating device 100 is correctly performed based on the mediation certificate. Hereinafter, the mechanism will be described in order.

  First, when there is a connection mediation request S2 from the connection mediation request unit 210A to the communication destination address reply unit 130, the communication destination address reply unit 130 receives the transmission of the connection mediation request S2 and specifies the communication source. Issue a mediation certificate indicating that the mediation processing from the terminal device 200A to the specific terminal device 200B as the communication destination has been executed. When the communication destination address reply S4 is performed, this intermediation certificate is returned to the communication source terminal device 200A together with the communication destination address “AD2”.

  Therefore, the communication start request unit 240A receives this mediation certificate together with the communication destination address “AD2”. Therefore, when the communication start request unit 240A makes the communication start request S5 to the communication destination address “AD2”, the communication start request unit 240A also transmits this mediation certificate. Then, the communication destination session establishment unit 230B receives the mediation certificate together with the communication start request S5.

  The communication destination session establishment unit 230B confirms the validity of the mediation certificate when the mediation certificate is transmitted together with the communication start request S5 with itself as the communication destination from another terminal device 200A that is the communication source. As a condition, a communication start acceptance confirmation S6 is transmitted to another terminal device 200A of the communication source, a communication session is established with another terminal device 200A of the communication source, and communication S7 is started. To. Of course, when the validity of the mediation certificate is not confirmed, the communication start acceptance confirmation S6 is not transmitted, and the communication S7 is not started.

  As described above, the mediation certificate in the above example proves that the connection mediating apparatus 100 “executes mediation processing from the terminal apparatus 200A to the terminal apparatus 200B”, and therefore the communication destination session establishment unit 230B. Can determine the validity of the mediation certificate by determining whether or not the content of the communication start request S5 matches the certification content of the mediation certificate. In the case of the above example, since the communication start request S5 has been transmitted from the terminal device 200A and is itself the terminal device 200B, the mediation proof that “the mediation process from the terminal device 200A to the terminal device 200B has been executed” is performed. The book can be judged to be correct.

  The communication destination session establishment unit 230B in the communication destination terminal device 200B receives the communication start request S5 from the communication source terminal device 200A, transmits a communication start acceptance confirmation S6 to the communication source terminal device 200A, and then receives the communication session. Is established and communication S7 is performed. At this time, if the received communication start request S5 is a legitimate signal, there is no problem. When the communication source terminal device 200A is infected with malware, the communication source terminal device 200A is hijacked by a cracker, and the communication start request S5 is made by an unauthorized method without following the regular procedure via the connection mediating device 100. There is also a possibility. Taking the above-mentioned countermeasure for issuing the intermediary certificate is effective in preventing such fraud by the cracker.

  Considering such a role of the mediation certificate, the communication destination address reply unit 130 may create the mediation certificate by the following method, for example. First, based on the connection mediation request S2, the location address (“AD1” in the illustrated example) of the specific terminal device 200A serving as the communication source and the location address (“AD1” in the illustrated example “ AD2 ") is recognized. Then, the intermediary certification data including both addresses is created. For example, a character string such as “AD1” + “AD2” may be used as intermediary certification data by concatenating the character strings of both addresses, and further, another secret character string “HAPPY” is added, A character string such as “AD1” + “AD2” + “HAPPY” may be used as mediation certification data.

  Subsequently, the data obtained by applying a one-way function using a predetermined encryption key to the mediation certification data thus created may be used as the mediation certificate. For example, as the one-way function, an encryption key for the communication source terminal device 200A, an encryption key for the communication destination terminal device 200B, or a hash function using both of these encryption keys can be used.

  For example, the intermediation certification data is composed of a character string “AD1” + “AD2” + “HAPPY”, and mediation is performed by applying a hash function using the public key of the communication destination terminal device 200B to the character string. Take the example of creating a certificate. The mediation certificate created in this way is a hash value of mediation certificate data.

  On the other hand, the communication destination session establishment unit 230B that has received the mediation certificate together with the communication start request S5 can confirm the validity of the mediation certificate in the following procedure. First, the location address “AD1” of the communication source terminal device 200A can be recognized as the transmission source address of the communication start request S5. Also, the user's own location address “AD2” can be recognized. Then, by using the secret character string “HAPPY” (the secret character string is managed so as to be known only by each component device of the network communication system) that has been decided in advance, “AD1” + Data for intermediation certification consisting of a character string “AD2” + “HAPPY” is created.

  Subsequently, a mediation certificate is created by applying a hash function using its own public key to the mediation certification data. Finally, it is only necessary to confirm that the mediation certificate created in this way matches the mediation certificate transmitted with the communication start request S5. If the two match, the validity of the mediation certificate is confirmed. Of course, if they do not match, the legitimacy cannot be confirmed, so it can be determined that there is a possibility that some kind of fraud has been performed. That is, when the validity of the mediation certificate cannot be confirmed, it is determined that the communication start request S5 received by the communication destination session establishing unit 230B is not made based on the regular mediation processing by the connection mediating apparatus 100. be able to. In such a case, the communication destination session establishment unit 230B does not transmit the communication start acceptance confirmation S6 and rejects establishment of the communication session.

  In the above example, the hash value for the mediation certification data “AD1” + “AD2” + “HAPPY” is used as the mediation certificate. Of course, the mediation certification data itself is used as the mediation certificate. It is also possible. However, in order to ensure sufficient security, it is preferable to use the hash value as the mediation certificate rather than the mediation certification data itself. Since the intermediary certification data includes location addresses such as “AD1” and “AD2”, the data is likely to be tampered with by a cracker. Therefore, in practice, as in the above example, it is preferable to create an intermediary certificate by applying a one-way function using some kind of encryption key.

  If an intermediary certificate is created using a one-way function such as a hash function, the original intermediary certificate data cannot be restored. The possibility of receiving can be reduced. In order to prevent unauthorized tampering, it is effective to add the secret character string such as “HAPPY” in the above example to create the mediation certification data. Of course, it is also possible to use variable elements such as the date, time, day of week, etc. when the intermediary certificate is issued as the secret character string.

<3-4. Modification (2) for improving security>
In §3-3 mentioned above, the modification which improved security about the 1st embodiment of the basic invention of the prior application described in §1 was described. Here, a modification in which the security is improved by the same method for the second embodiment of the basic invention of the prior application described in §2 will be described.

  FIG. 14 is a block diagram showing a modified example in which security is improved in the network communication system according to the second embodiment shown in FIG. In this modification, two measures are taken to improve security for the network communication system according to the second embodiment.

  The first countermeasure is the addition of mutual authentication processing. When transmitting and receiving information indicated by the dashed arrows in the figure, mutual authentication processing for confirming the authenticity of the other party is performed between the two. Specifically, first, when transmitting the connection mediation request S12 from the communication source terminal device 400B to the connection mediation device 300, the communication source terminal device 400B and the connection mediation device 300 mutually communicate with each other's devices. Mutual authentication processing is performed to confirm the authenticity of. The arrow indicating the connection mediation request S12 is a broken line, indicating that this mutual authentication process is performed.

  Similarly, when the connection mediating device 300 performs the communication source address transmission S14 to the communication destination terminal device 400A, the authenticity of the other device between the connection mediating device 300 and the communication destination terminal device 400A. Mutual authentication processing for confirming the above is performed. The arrow indicating the connection mediation request S14 is a broken line, indicating that this mutual authentication process is performed. Therefore, each terminal device 400 and the connection mediating device 300 have the authentication processing function described above.

  In the case of the system shown in FIG. 14, when the communication start request S15 is transmitted from the communication destination terminal device 400A to the communication source terminal device 400B, the communication destination terminal device 400A and the communication source terminal device 400B are also connected. Then, mutual authentication processing is performed to mutually confirm the authenticity of the counterpart devices. The arrow indicating the communication start request S15 is a broken line, indicating that this mutual authentication process is performed. Accordingly, each terminal device 400 has such an authentication processing function.

  In the case of the illustrated example, the mutual authentication process when the communication source terminal device 400B performs the communication start acceptance confirmation S16 to the communication destination terminal device 400A is omitted (the arrow indicating the communication start acceptance confirmation S16 is a solid line) Drawn in). This is because when the communication start request S15 is transmitted, the mutual authentication process between the communication destination terminal device 400A and the communication source terminal device 400B has already been completed, and the authenticity of the counterpart device has been confirmed. Because it is. Of course, the mutual authentication process may be executed again when the communication start acceptance confirmation S16 is performed.

  The specific method of mutual authentication processing is as already described in §3-3. In the case of the modification shown in FIG. 14, the communication S17 between the two terminal devices after establishment of the communication session may be performed by encrypted communication using the encryption key used for the mutual authentication process.

  In the system shown in FIG. 14, the second countermeasure taken to improve security is issuance of a mediation certificate by the connection mediating apparatus 300. In the illustrated example, the connection mediating apparatus 300 plays a role of mediating the connection between the communication source terminal apparatus 400B and the communication destination terminal apparatus 400A. The mediation certificate is a certificate issued by the connection mediating apparatus 300 in order to prove the fact that “such mediation is surely performed”. The communication source terminal device 400B can confirm that the mediation by the connection mediating device 300 is correctly performed based on the mediation certificate. Hereinafter, the mechanism will be described in order.

  First, when there is a connection mediation request S12 from the connection mediation request unit 410B to the communication source address transmission unit 330, the communication source address transmission unit 330 receives the transmission of the connection mediation request S12 and specifies the communication source. A mediation certificate indicating that the mediation processing from the terminal device 400B to the specific terminal device 400A as the communication destination has been executed is issued. Then, when the communication source address reply S14 is performed, the mediation certificate is returned to the communication destination terminal device 400A together with the communication source address “AD2”.

  Therefore, the communication start request unit 440A receives this mediation certificate together with the communication source address “AD2”. Therefore, the communication start request unit 440A transmits this mediation certificate together when making the communication start request S15 for the communication source address “AD2”. Then, the communication source session establishment unit 430B receives the mediation certificate together with the communication start request S15.

  The communication source session establishment unit 430B confirms the validity of the mediation certificate when the mediation certificate is transmitted together with the communication start request S15 having itself as the communication source from another terminal device 400A as the communication destination. As a condition, a communication start acceptance confirmation S16 is transmitted to another terminal device 400A at the communication destination, a communication session is established with another terminal device 400A at the communication destination, and communication S17 is started. To. Of course, when the validity of the mediation certificate is not confirmed, the communication start acceptance confirmation S16 is not transmitted, and the communication S17 is not started.

  As described above, the mediation certificate in the above example proves that the connection mediating apparatus 300 “executes mediation processing from the terminal apparatus 400B to the terminal apparatus 400A”, and therefore, the communication source session establishment unit 430B. Can determine the validity of the mediation certificate by determining whether or not the content of the communication start request S15 matches the certification content of the mediation certificate. In the case of the above example, the communication start request S15 has been transmitted from the terminal device 400A, and since the self-confidence is the terminal device 400B, the mediation proof that “the mediation process from the terminal device 400B to the terminal device 400A has been executed” is performed. The book can be judged to be correct.

  The communication source session establishment unit 430B in the communication source terminal device 400B receives the communication start request S15 from the communication destination terminal device 400A, transmits a communication start acceptance confirmation S16 to the communication destination terminal device 400A, and then receives the communication session. Is established and communication S17 is performed. At this time, if the received communication start request S15 is a legitimate signal, there is no problem, but if it is a camouflaged signal by a cracker, there is a risk of suffering fraud. Further, when the communication destination terminal device 400A is infected with malware, the communication device is hijacked by a cracker, and the communication start request S15 is made by an unauthorized method without following the regular procedure via the connection mediating device 300. There is also a possibility. Taking the above-mentioned countermeasure for issuing the intermediary certificate is effective in preventing such fraud by the cracker.

  The specific method for creating the broker certificate is as described in §3-3. That is, in the case of the modification shown in FIG. 14, the communication source address transmission unit 330 also includes the location address “AD2” of the specific terminal device 400B serving as the communication source and the location address “specific address of the specific terminal device 400A serving as the communication destination. The intermediary certificate is obtained by applying a one-way function using a predetermined encryption key to intermediary certification data including "AD1" (other secret character strings may be added as necessary). Create it. As the one-way function, an encryption key for the communication source, an encryption key for the communication destination, or a hash function using both encryption keys can be used. The specific procedure for confirming the validity using such an intermediation certificate is as already described in §3-3, and the description thereof is omitted here.

<<< §4. Practical embodiment using router >>>
In the first embodiment and the second embodiment of the basic invention of the prior application described so far, each of the terminal devices 200A to 200D and 400A to 400D is directly connected to the network N (Internet) for convenience of showing the basic principle of each invention. The description has been made with reference to the connected states (see FIGS. 1 and 6). However, each terminal device is normally connected to a network N (Internet) via a router. Therefore, here, a practical embodiment in which a terminal device is connected to a network via a router will be described for the basic invention of the prior application.

<4-1. Basic embodiment using router>
FIG. 15 is a block diagram showing an embodiment of the basic invention of the prior application in which a terminal device is connected to the network N via a router. Specifically, FIG. 15 shows a state in which three terminal devices 200E, 200F, and 200G are connected to the network N (Internet) via the same router R.

  As already described, the terminal device 200 in the basic invention of the prior application is any device as long as it is an electronic device having a function of connecting to the network N and performing communication such as a personal computer, a mobile phone, and a tablet terminal. It doesn't matter. Recently, enterprise LANs and home LANs have become widespread, and personal computers and tablet terminals are usually connected to the Internet via routers installed in businesses and homes. In recent mobile phone communication networks, a base station system having a router function has been used, and the mobile phone can be connected to the Internet via the base station system having the router function.

  Accordingly, each terminal device used in the basic invention of the prior application is practically connected to the Internet via the router R as illustrated in FIG. The router R has a function of constructing a LAN. In the example shown in the figure, the portion drawn on the left side of the router R constitutes one subnet and is assigned a class C private IP address. Specifically, an IP address having a network unit “192.168” and host units “0.11,” “0.12,” and “0.13” is assigned to each terminal device. Communication between devices in the subnet can be performed without going through the router R. However, when accessing devices outside the subnet, communication through the router R is required.

  In the illustrated example, the terminal device 200E (terminal ID: 0050) is assigned a private IP address “192.168.0.11”, and the terminal device 200F (terminal ID: 0060) is assigned a private address “192.168.0.12”. An IP address is assigned, and a private IP address “192.168.0.13” is assigned to the terminal device 200G (terminal ID: 0070). In actual communication, port numbers are used together with these IP addresses. In the figure, port number P1 is assigned to one communication path of terminal device 200E, port numbers P2 and P3 are assigned to two communication paths of terminal device 200F, and port numbers P4 to P7 are assigned to four communication paths of terminal device 200G. Examples given are shown.

  The port number is composed of 2-byte data and is used to specify the communication end point. For example, in the terminal device 200F shown in the figure, two sets of application programs APP1 and APP2 that operate under a predetermined OS program are installed, and the port number P2 is assigned to the communication path for APP1. Is assigned a port number P3. Therefore, even for communication using the same IP address “192.168.0.12”, it is possible to distinguish between communication for APP1 and communication for APP2 by the difference in port numbers P2 / P3.

  On the other hand, although two sets of application programs APP1 and APP2 are installed in the terminal device 200G shown in the figure, two sets of port numbers P4 and P5 are assigned to APP1, and two sets of port numbers are set for APP2. P6 and P7 are assigned. In this way, it is possible to assign a plurality of port numbers to the same application program and distinguish a plurality of communication paths from each other. For example, when the application program APP1 is a Web browser program, the port number P4 is assigned to the communication for the first Web page, and the port number P5 is assigned to the communication for the second Web page. For example, separate and independent communication is possible with respect to different Web servers. Thus, the port number can be arbitrarily assigned to each application program.

  Here, the following description will be continued on the assumption that the illustrated application program APP2 is a dedicated communication application program for performing the function as the network communication system according to the basic invention of the prior application. In other words, the illustrated terminal devices 200F and 200G are devices such as general-purpose personal computers, smartphones, and tablet terminals that operate under the control of a predetermined OS program, and a dedicated communication application program APP2 is installed in the devices. By doing so, these devices function as terminal devices according to the prior invention basic invention.

  In this case, the self-address notification unit 250, the communication request reception unit 220, the connection mediation request unit 210, the communication start request unit 240, the communication source session establishment unit 260, and the communication destination session establishment which are the components of the terminal device 200 illustrated in FIG. The processing function by the unit 230 is realized by executing the communication application program APP2 (some processing functions may be realized by executing the OS program). Similarly, a self-address notification unit 450, a communication request reception unit 420, a connection mediation request unit 410, a communication start request unit 440, a communication source session establishment unit 430, and a communication destination session establishment which are components of the terminal device 400 illustrated in FIG. The processing function by the unit 460 is realized by executing the communication application program APP2 (some processing functions may be realized by executing the OS program).

  In FIG. 15, the block indicating the application program APP2 and its communication path are indicated by bold lines. Communication between the terminal devices 200E, 200F, and 200G and devices outside the subnet is performed via the router R. The router R has a network address translation function (NAT (Network Address Translation) function), and the private IP address assigned to the communication path connected to the inside (the left side of the router R in the figure) is assigned to the outside (the figure). The communication path connected to the right side of the router R) is converted into a global IP address assigned, and vice versa.

  In the case of the illustrated example, a private IP address “192.168.0.11” to “192.168.0.13” assigned to the inside of the router R and a global IP address “xx.73.5.111” assigned to the outside of the router R (Hereinafter referred to as ADx). Note that xx in the global IP address indicates arbitrary 1-byte data (in this application, in order to avoid specifying a unique global IP address, a part of the global IP address is xx, yy, zz, etc. I will show it with a symbol). In the address conversion, the port number is also converted by a function generally called NAPT (Network Address Port Translation).

  For example, the combination “192.168.0.12 (P3)” of the private IP address and the port number assigned to the communication path from the communication application program APP2 of the terminal device 200F is the combination “xx. 73.5.111 (P13) ”. Therefore, for an external device connected via the network (Internet) N, the APP2 of the terminal device 200F has a location address “xx.73.5.111 (P13)” (information obtained by adding a port number to an IP address). Will be specified. Similarly, APP2 of the terminal device 200G is specified by the location address “xx.73.5.111 (P16)” or “xx.73.5.111 (P17)”.

  In the example shown in the figure, the same global IP address ADx (specifically “xx.73.5.111”) is assigned to a plurality of communication paths outside the router R, but the port numbers are respectively Because they are different, they can be distinguished from each other. Conversely, when there is an access from the device outside the router R to the inside device, processing for converting the global IP address ADx into a private IP address is performed. For example, when there is an access to an address “xx.73.5.111 (P16)” from an external device, the address is converted to “192.168.0.13 (P6)” and the communication application program of the terminal device 200G It is processed as an access addressed to the first communication path of APP2. Since such a NAPT function is an existing technology that is widely used, detailed description thereof is omitted here.

  Now, as shown in FIG. 2, the terminal device 200, which is a component of the network communication system according to the basic invention of the prior application, includes a self-address notifying unit 250. A process of notifying the connection mediating apparatus 100 of the location address indicating the above location is performed. As described above, this notification process is actually executed by the communication application program APP2 installed in the terminal device 200.

  Therefore, also in the embodiment shown in FIG. 15, the communication application program APP2 notifies the location address to the connection mediating apparatus 100, and the address table update unit 120 in the connection mediating apparatus 100 receives this, For each terminal device, a process of writing information in which the terminal ID and the location address are associated with each other into the address table T in the address table storage unit 110 is executed.

  In the case of the embodiment shown in FIG. 15, since the terminal devices 200F and 200G are connected to the network N via the router R, the self-address notification unit 250 has a private IP in the LAN (subnet) managed by the router R. A process of notifying an address as a location address is performed. However, this private IP address is converted to the global IP address ADx by the NAT function by the router R and transmitted to the network N. Therefore, the address reaching the connection mediating apparatus 100 is not the private IP address but the global IP address ADx, and the address table updating unit 120 stores the global IP address ADx in the address table T as the location address. I do.

  In the embodiment shown in FIG. 15, information obtained by adding a port number to an IP address is used as a location address indicating the location of each terminal device on the network. For this reason, the self-address notifying unit 250 performs processing for notifying the private IP address with the port number added as the location address, and the router R converts the information into information with the global IP address added with the port number. , It reaches the connection mediating apparatus 100. Therefore, information in which the port number is added to the global IP address is written in the address table T as the location address.

  FIG. 16 is a diagram showing an example of an address table when information obtained by adding a port number to an IP address is used as a location address in the embodiment shown in FIG. The address table T41 shown in FIG. 16A is based on the notification from the self-address notification unit 250 (communication application program APP2) in the terminal device 200F (terminal ID: 0060) shown in FIG. ”And a notification from the self-address notification unit 250 (communication application program APP2) in the terminal device 200G (terminal ID: 0070). In this example, the location address (combination of IP address ADx and port number P16 and combination of IP address ADx and port number P17) corresponding to “terminal ID: 0070” is written.

  In the case of the example shown in FIG. 15, the self-address notification unit 250 (communication application program APP2) in each of the terminal devices 200F and 200G performs processing of transmitting information with a port number added to a private IP address as a location address. Since the router R converts the information into a global IP address added with a port number, the location address actually stored in the address table T41 is a combination of the global IP address ADx and the converted port number as shown in the figure. become.

  For example, from the self-address notifying unit 250 of the terminal device 200F, information obtained by adding the port number “P3” to the private IP address “192.168.0.12” as the location address indicating the location of the transmission source itself is the terminal ID “ ”Is transmitted together with information indicating“ 0060 ”, but when passing through the router R, the location address indicating the location of the transmission source is the global IP address“ xx.73.5.111 ”and the port number“ P13 ”. Will be converted to information with the. Therefore, a combination of the global IP address ADx “xx.73.5.111” and the port number “P13” is written in the address table T41 as the belonging address corresponding to the terminal ID “0060”.

  The address table T42 shown in FIG. 16 (b) exemplifies the information in the location address column of the address table T41 shown in FIG. 16 (a) as specific data. As described above, in the case of the example shown in FIG. 15, the global IP address “xx.73.5.111” is given to the communication path outside the router R, and therefore the address table T42 shown in FIG. In each of the IP address fields, data “xx.73.5.111” is stored. On the other hand, the port number assigned to the communication path outside the router R is a 2-byte number generated by the router R so as not to overlap each other. In the example shown in FIG. 16B, it is 62801 to 62803. Data is stored.

  Eventually, the connection mediating apparatus 100 shown in FIG. 15 stores the address table T42 as shown in FIG. 16B for the terminal apparatuses 200F and 200G. Therefore, when there is a connection mediation request including the terminal ID “0060” as the communication destination specifying information from an external communication source not shown, the communication destination address reply unit 130 in the connection mediating apparatus 100 refers to the address table T42. As a result, the location address corresponding to the terminal ID “0060” (information obtained by adding the port number “62801” to the IP address “xx.73.5.111”) is returned as the communication destination address. Therefore, the terminal device serving as the communication source can make a communication start request to the communication destination specified by the IP address “xx.73.5.111” and the port number “62801”.

  The example in which the router R is used in the first embodiment (embodiment using the connection mediating apparatus 100 and the terminal device 200) mainly shown in FIG. 1 has been described above, but the second embodiment (connection mediation) shown in FIG. The same applies to the case where the router R is used in the embodiment in which the device 300 and the terminal device 400 are used.

  Note that the address table updating units 120 and 320 in the connection mediating devices 100 and 300 update the address table illustrated in FIG. 16 every time a notification of a location address is received from the self-address notification unit 250 or 450 of each terminal device. Process. As described above, in the case of the embodiment shown in FIG. 15, the processing function of the self-address notification unit of the terminal devices 200F and 200G is realized by executing the communication application program APP2 that operates under the management of a predetermined OS program. .

  Therefore, in practice, the self-address notification processing by the self-address notification units 250 and 450 is preferably performed at the timing shown in the table of FIG. Timing (1) in the illustrated table is when the user inputs an operation to the communication application program APP2. For example, after starting the communication application program APP2, a message such as “Do you want to prepare for communication (Yes / No)?” Is displayed, and when the user inputs an operation to instruct “Yes”, An address notification process may be performed. Normally, when the communication application program APP2 is activated, the private IP address of the terminal device and the corresponding global IP address are already determined, and the environment for performing the self-address notification processing is prepared.

  Timing (2) in the illustrated table is when the communication application program APP2 is activated. When this timing (2) is adopted, the self-address notification process is automatically executed without waiting for the above-described message display or user operation input. Actually, the processing functions as the self-address notification units 250 and 450 may be incorporated in the startup routine of the program APP2.

  Timing (3) in the illustrated table is when the OS program is started, and is substantially when the terminal device is started. When this timing (3) is adopted, the processing functions as the self-address notification units 250 and 450 may be incorporated in the OS program startup routine. Normally, in the startup routine of the OS program, the process of determining the private IP address of the terminal device and the corresponding global IP address is performed, so that the self-address notification process should be automatically performed thereafter. Good.

<4-2. Example using VPN>
Next, an embodiment using a VPN (Virtual Private Network) in the network communication system according to the basic invention of the prior application will be described. FIG. 15 illustrates an embodiment in which a terminal device is connected to the network N via the router R. In this example, the local network constructed inside the router R (the left side in the figure) constitutes one private network, and each of the terminal devices 200E, 200F, and 200G includes a network unit “192.168”. A private IP address starting with is assigned. As a method for securely extending such a private network across a public network such as the Internet N, VPN technology has become widespread.

  FIG. 18 is a block diagram showing the overall configuration of an embodiment using VPN in the network communication system according to the prior invention basic invention. Here, for convenience of explanation, three terminal devices 200H, 200I, and 200J (terminal IDs are 0081, 0082, and 0083, respectively) set at a Tokyo head office of a certain company and one terminal installed at a Paris branch office A simple example is shown in which a VPN is constructed by a total of four terminal devices 200K (terminal ID is 0091). The three terminal devices 200H, 200I, and 200J installed at the Tokyo head office are called the first terminal devices belonging to the first group, and the one terminal device 200K installed at the Paris branch office is assigned to the second group. It will be called the second terminal device to which it belongs.

  As illustrated, the first terminal devices 200H, 200I, and 200J are connected to the network (Internet) N via the first router R1, and the second terminal device 200K is connected to the second router R2. Connected to a network (Internet) N. Therefore, basically, the first terminal devices 200H, 200I, and 200J arranged above the first router R1 in the figure are hosts in the first LAN managed by the first router R1. In the figure, the second terminal device 200K arranged below the second router R2 is a host in the second LAN managed by the second router R2.

  Therefore, the first terminal devices 200H, 200I, and 200J are assigned a private IP address in the first LAN managed by the first router R1, and the second terminal device 200K has a second router. A private IP address in the second LAN managed by R2 is assigned. Similarly to the example shown in FIG. 15, the port number is also given along with the IP address.

  In the illustrated example, a private IP address of class B is assigned to the first LAN, and “172.16.6.11 (P1)” and “172.16” are assigned to the first terminal devices 200H, 200I, and 200J, respectively. .6.12 (P2) "and" 172.16.6.13 (P3) "are assigned IP addresses and port numbers (port numbers P1, P2, P3, etc. are actually 2-byte data). These pieces of information are stored in the global IP addresses ADy of “yy.88.105.19 (P11)”, “yy.88.105.19 (P12)”, and “yy.88.105.19 (P13)” by the first router R1, respectively. Is converted into a combination of the port number and the Internet N. On the other hand, in the illustrated example, a private IP address of class C is assigned to the second LAN, and the IP address and port number “192.168.99.11 (P4)” are given to the second terminal device 200K. Is granted. This information is converted into a combination of a global IP address ADz “zz.99.214.28 (P21)” and a port number by the second router R2, and then connected to the Internet N.

  In this state, the first LAN to which the first terminal devices 200H, 200I, and 200J belonging to the first group belong, and the second LAN to which the second terminal device 200K belonging to the second group belongs. Are independent private networks, but in the illustrated embodiment, a VPN for extending the range of the first LAN across the Internet N is constructed. That is, the second terminal device 200K is given the private IP address and port number “192.168.99.11 (P4)” in the second LAN managed by the second router R2, and the first router R1. The private IP address and port number “172.16.6.14 (P5)” in the first LAN managed by the network are virtually assigned as VIP addresses, and the first terminal devices 200H, 200I, 200J and the second A VPN is set up with the terminal device 200K so as to be able to communicate with each other using this VIP address.

  Therefore, as indicated by a broken line in the figure, the terminal device 200K installed in the Paris branch office is similar to the terminal devices 200H, 200I, and 200J installed in the Tokyo head office, and the first LAN managed by the first router R1. It can be handled as a terminal device. FIG. 19 is a diagram showing the principle of VNP communication in the embodiment shown in FIG. The illustrated example shows VPN communication between the terminal device 200H installed at the Tokyo head office and the terminal device 200K installed at the Paris branch office.

  As shown in FIG. 19, a VPN communication unit 201H is provided in the terminal device 200H, and a VPN communication unit 201K is provided in the terminal device 200K, and a VPN encryption communication path is established therebetween. Since the data exchanged between the two is encrypted, the information is actually transmitted via a public network such as the Internet N, but it is as if it is convenient and secure via a private network. Information can be sent and received. The VPN communication units 201H and 201K are actually constructed by a dedicated VPN application program installed in each terminal device. Since the specific mechanism of such a VPN is a well-known technique, detailed description is abbreviate | omitted here.

  When such a VPN mechanism is used in the network communication system according to the basic invention of the prior application, it is convenient to store the VIP address in the address table T stored in the connection mediating apparatus 100. is there. FIG. 20 is a diagram showing an example of an address table to which VIP addresses are added for use in the embodiment shown in FIG. The address table T51 shown in FIG. 20A is based on the location address (IP address and port) corresponding to each terminal ID based on the notification from the self-address notification unit 250 in the terminal devices 200H to 200K that are members of the VPN. Number).

  Here, the terminal devices 200H to 200J (terminal ID: 0081 to 0083) are devices belonging to the first LAN constructed in the Tokyo head office, but the terminal device 200K (terminal ID: 0091) is assigned to the Paris branch office. It is a device belonging to the constructed second LAN. However, the first LAN is virtually expanded to the terminal device 200K by the VPN mechanism described above, and a VIP address “VIP (200K)” is assigned to the terminal device 200K. For this reason, for the terminal ID “0091” in the address table T51 shown in FIG. 20A, a VIP address “VIP (200K)” is further stored in the VIP column.

  The address table T52 shown in FIG. 20 (b) exemplifies the information in the location address column and the VIP column of the address table T51 shown in FIG. 20 (a) as specific data. In the case of the example shown in FIG. 18, information obtained by adding port numbers P11 to P13 to the global IP address ADy “yy.88.105.19” is assigned to each communication path outside the first router R1 as a location address. Therefore, the data “yy.88.105.19” are stored in the IP address fields of the terminal IDs “0081 to 0083” of the address table T52 shown in FIG. 2 stores the 2-byte number “54701 to 54703” generated by the first router R1.

  On the other hand, since the information obtained by adding the port number P21 to the global IP address ADz “zz.99.214.28” is given to each communication path outside the second router R2 as the location address, FIG. The data “zz.99.214.28” is stored in the IP address column of the terminal ID “0091” of the address table T52 shown in FIG. 5B, and the data generated by the second router R2 is stored in the port number column. A 2-byte number “61999” is stored. Further, in the VIP column of the terminal ID “0091”, a VIP address “172.16.6.14” (virtual private address for the first LAN given to the terminal device 200K by the VPN setting) Is stored.

  Thus, in order to store the VIP address “172.16.6.14” in the VIP column of the address table T52, the VPN setting is made to the connection mediating apparatus 100 in the self-address notifying unit 250 of the second terminal apparatus 200K. The function of notifying the VIP address assigned by the second terminal device 200K can be provided in the address table updating unit 120 in association with the location address of the second terminal device 200K and stored in the address table T52. That's fine.

  In this way, if the VIP address of the second terminal device 200K is stored in the address table T52, for example, when the first terminal device 200H performs communication using the second terminal device 200K as a communication destination. In addition, the connection mediation request unit 210 of the first terminal device 200H can specify the communication destination using the VIP address “VIP (200K)” of the second terminal device 200K as the communication destination specifying information.

  Specifically, if the connection mediation request unit 210 of the terminal device 200H makes a connection mediation request including the VIP address “172.16.6.14” as the communication destination identification information, the communication destination address in the connection mediation device 100 The reply unit 130 returns the location address “zz.99.214.28 (61999)” corresponding to the VIP address “172.16.6.14” as a communication destination address by referring to the address table T52 shown in FIG. be able to. Normally, when a VPN is set, the terminal device 200K is recognized as a device having a VIP address of “172.16.6.14” in the application program layer, so a connection mediation request is made using this VIP address. It would be convenient if it could be done.

  Of course, if necessary, the port number “P5” may be stored together with the VIP address “172.16.6.14”. Then, using the information “172.16.6.14 (P5)”, it is possible to make a connection mediation request including designation of a specific port number.

  As described above, an example in which the VPN is set and the range of the private network is virtually expanded in the first embodiment (embodiment using the connection mediating apparatus 100 and the terminal apparatus 200) of the basic invention of the prior application shown in FIG. However, the same applies to the case where VPN setting is performed in the second embodiment of the basic invention of the prior application shown in FIG.

<<< §5. Technical problems to be solved by the present invention >>>
So far, the network communication system according to the basic invention of the prior application described in International Publication No. WO2017 / 145984 has been described. The present invention proposes a new method for connecting an inexpensive IoT device intended for personal use to the Internet while ensuring sufficient security by utilizing the basic invention of the prior application.

  Therefore, first, a brief description will be given of problems that occur when an IoT device is connected to the Internet by a conventional general method. FIG. 21 is a block diagram illustrating a specific example in which an IoT device intended for personal use is connected to the Internet. This figure shows an example in which various home appliances installed in the home H and various electrical components incorporated in the car C are connected to the network (Internet) N. Specifically, in the home H, a surveillance camera H1, an air conditioner H2, a refrigerator H3, a video deck H4, a smart key H5, a health appliance H6 (such as a smart weight scale), and an AI speaker H7 are installed. A smart key C1, an air conditioner C2, a navigation system C3, and an audio C4 are incorporated therein.

  These home appliances H1 to H7 and electrical components C1 to C4 are all IoT devices (devices having a function of connecting to the Internet), and are connected to the Internet N as shown. On the other hand, in the case of the illustrated example, terminal devices such as the smartphone 11, the personal computer 12, and the update server 13 are connected to the Internet N, and these terminal devices 11 to 13 are all connected via the Internet N. It is possible to communicate with the IoT devices H1 to H7 and C1 to C4.

  Therefore, the user who lives in the home H and owns the car C can operate the desired IoT device by operating the smartphone 11 or the personal computer 12 from the office or the like, so the convenience is greatly improved. . Further, as necessary, each IoT device can download a predetermined updater from the update server 13 and update the built-in firmware, so that the operation using the latest program is always possible.

  FIG. 21 shows an example in which the IoT devices H1 to H7, C1 to C4 and the terminal devices 11 to 13 are directly connected to the Internet N. However, an embodiment in which the IoT devices H1 to H7 and C1 to C4 are connected to the network N via a router is also shown. Generally used. Of course, in preparation for an external hacking attack, it is preferable that both the IoT device and each terminal device are connected to the network via a router. However, in a surveillance camera or the like, if it is connected to the Internet N via a router, the handling procedure becomes complicated. Therefore, there are not a few forms that are directly connected to the Internet N and used.

  However, as long as each IoT device is connected to the Internet N, a security problem always occurs. As illustrated, an unauthorized terminal device 19 can be connected to the Internet N, and a cracker may attempt to hack each IoT device using the terminal device 19. In particular, as in the illustrated example, an IoT device directly connected to the Internet N is very easy to access by an unauthorized terminal device 19, and the risk of being hacked is very high.

  In contrast, when each IoT device is connected to the Internet N via a router, the effect of security measures is slightly improved. If a router is provided between the Internet N and the IoT device, the unauthorized terminal device 19 can access the router using its global IP address, but the IoT device under the router. Since the private IP address assigned to is unknown, it is not possible to access a specific IoT device by a normal method. However, as illustrated in FIG. 15, if the port number is designated, the NAPT function of the router enables access to the private IP address of a specific IoT device. In other words, a general router has to accept a specific port number from the outside and accepts it if the port number is valid. Therefore, even if a connection is made via a router, the risk of hacking still remains.

  Moreover, in the case of IoT devices such as home appliances and automobile electrical components intended for personal use, the CPU and memory configurations are poor compared to general computer devices, and sufficient security measures are not taken. Is the current situation. For example, the IoT devices H1 to H7 and C1 to C4 shown in FIG. 21 are generally operated without incorporating anti-virus software. For this reason, when these IoT devices are hacked from an unauthorized terminal device 19, there is a high possibility that they will be infected with malware and become bots because they lack protection means.

  Further, in a general IoT device, it is necessary to periodically update the internal firmware. Originally, this update is performed by connecting to a dedicated update server 13 via the Internet N. However, when an attack by a cracker is received, the update is not made to the regular update server 13 but to an unauthorized terminal device 19. Connected and falls into a situation where a fake updater containing malware is installed.

  Usually, the update processing is performed by a push type distribution in which update data is voluntarily distributed from the update server 13 side to the IoT device side, and by sending an update request to the update server 13 from the IoT device side. Depending on the situation, a pull-type distribution in which downloading of the updater is started is used. However, any of the forms may be hacked.

  In other words, in the case of adopting the push-type distribution form, if an unauthorized terminal device 19 disseminates the update server 13 and distributes the update data, the IoT device that accepts the update data will be infected with malware. It will be. On the other hand, in the case of adopting a pull-type distribution form, an update request is sent from the IoT device side to the regular update server 13, but if a DNS spoofing attack designed by a cracker is received, an update request is sent. The request is guided not to the regular update server 13 but to an unauthorized terminal device 19 and receives a fake updater.

  In this way, it can be said that IoT devices such as home appliances and automobile electrical components intended for personal use have security vulnerabilities as compared to general computer devices. The present invention proposes a new proposal for solving such a problem, and its purpose is to connect an inexpensive IoT device intended for personal use to the Internet while ensuring sufficient security. An object of the present invention is to provide a network communication system.

<<< §6. Basic embodiment of the present invention >>
Subsequently, the present invention will be described based on a basic embodiment shown in the drawings. FIG. 22 is a block diagram showing the overall configuration of the network communication system according to the basic embodiment of the present invention. As shown in the figure, this network communication system includes a plurality of terminal devices (four terminal devices 600A to 600D shown in the figure) that can be connected to each other via a network N (Internet), and a plurality of these terminal devices. A connection mediating device 500 that mediates the connection between the terminal devices, and a gateway device GW (indicated by a bold block in the figure) including one of the terminal devices (600A in the illustrated example), It has.

  In the illustrated example, the terminal device 600A is a terminal device included in the gateway device GW, and the terminal devices 600B, 600C, and 600D are terminal devices located outside the gateway device GW. Therefore, for convenience of explanation, the terminal device 600A is referred to as an “internal terminal device”, and the terminal devices 600B, 600C, and 600D are referred to as “external terminal devices”.

  The gateway device GW is a characteristic component of the present invention, and plays a role of connecting one or more IoT devices connected to the downstream side to a network N (Internet) connected to the upstream side. The gateway device GW includes an internal terminal device 600A and further includes additional components such as an IoT device registration table TT. In the case of the illustrated example, five IoT devices 701 to 705 installed in the home H are connected to the downstream side of the gateway device GW. Specifically, the IoT device 701 is a surveillance camera, the IoT device 702 is an air conditioner, the IoT device 703 is a refrigerator, the IoT device 704 is a video deck, and the IoT device 705 is a smart key.

  Actually, the gateway device GW is preferably installed in the home H. Of course, the IoT device connected to the downstream side of the gateway device GW is not limited to home appliances used in the home, and may be various electrical components used in the automobile C shown in FIG. In this case, the gateway device GW is preferably incorporated in the automobile C.

  The gateway device GW is a device that performs the same function as a router, and the five IoT devices 701 to 705 installed in the home H are connected to the Internet N via the gateway device GW. However, a general router gives a private IP address to a subordinate device connected to the downstream side, and communicates by exchanging IP packets with the subordinate device. In the case of the present invention, it is not always necessary to assign a private IP address to each of the IoT devices 701 to 705, and communication between the gateway device GW and the subordinate IoT devices 701 to 705 is not necessarily communication for exchanging IP packets. There is no need to make it.

  A major difference between the gateway device GW according to the present invention and a general router is that communication with the network N (Internet) is performed by the internal terminal device 600A. The network communication system shown in FIG. 22 is configured by using the first embodiment (see FIG. 1) or the second embodiment (see FIG. 6) of the basic invention of the prior application. Each terminal ID for identifying each terminal device is assigned to 600D. The connection mediating apparatus 500 executes a process for mediating the connection between the terminal device serving as the communication source and the terminal device serving as the communication destination using the terminal ID. Therefore, communication via the network N between the external terminal devices 600B to 600D and the gateway device GW (internal terminal device 600A) is started by mediation by the connection mediating device 500.

  Here, both the internal terminal device 600A and the external terminal devices 600B to 600D are described in each component (see FIG. 2) of the terminal device 200 described in the first embodiment of the basic invention of the prior application or in the second embodiment. Each component of the terminal device 400 (see FIG. 7) is included. In addition, the connection mediating apparatus 500 is configured by each component (see FIG. 1) of the connection mediating apparatus 100 described in the first embodiment of the basic invention of the prior application or each configuration of the connection mediating apparatus 300 described in the second embodiment. It has an element (see FIG. 6).

  More specifically, when the network communication system according to the present invention is configured using the first embodiment of the basic invention of the prior application, each of the terminal devices 600A to 600D shown in FIG. 2, the connection mediation request unit 210, the communication request reception unit 220, the communication destination session establishment unit 230, the communication start request unit 240, the self address notification unit 250, the communication source session establishment unit 260, and the components of the terminal device 200 shown in FIG. Equivalent components are provided. 22 includes the same components as the address table storage unit 110, the address table update unit 120, and the communication destination address reply unit 130, which are the components of the terminal device 100 shown in FIG. Will be.

  On the other hand, when the network communication system according to the present invention is configured using the second embodiment of the basic invention of the prior application, each of the terminal devices 600A to 600D shown in FIG. 22 is the terminal device 400 shown in FIG. Which are equivalent to the connection mediation request unit 410, the communication request accepting unit 420, the communication source session establishing unit 430, the communication start request unit 440, the self address notifying unit 450, and the communication destination session establishing unit 460. Will be. 22 includes the same components as the address table storage unit 310, the address table update unit 320, and the communication source address transmission unit 330, which are the components of the terminal device 300 shown in FIG. Will be.

  Therefore, the mutual communication between the terminal devices 600A to 600D shown in FIG. In the case of the illustrated example, the terminal ID “0110” is assigned to the internal terminal device 600A incorporated in the gateway device GW. In the illustrated embodiment, the external terminal device 600B is a smartphone to which the terminal ID “0120” is assigned, and the external terminal device 600C is a personal computer to which the terminal ID “0130” is assigned. Here, the following description will be given on the assumption that the external terminal devices 600B and 600C are smartphones or portable personal computers owned by residents of the home H. On the other hand, the external terminal device 600D is an update server to which a terminal ID “0140” is assigned, and an update process for each IoT device 701 to 705 installed in the home H is executed by this update server. The following description will be given.

  The address table T in the connection mediating apparatus 500 includes the terminal IDs “0110”, “0120”, “0130”, “0140” and the current location addresses “AD11”, “AD12” for each of the terminal devices 600A to 600D. , “AD13”, “AD14” are recorded. Therefore, even if the addresses of the terminal devices 600A to 600D are changed, the address of the communication destination can always be grasped by referring to the address table T, and appropriate mediation processing by the connection mediating device 500 is executed. This is as already explained in §1 and §2.

  Actually, communication between the internal terminal device 600A and the external terminal devices 600B to 600D is executed by the procedure described in §1 or §2. Therefore, the description of the processing function of each component constituting the terminal devices 600A to 600D and the specific procedure of mediation processing is omitted here. Of course, also in the network communication system shown in FIG. 22, the modified example described in §3 and the practical embodiment described in §4 can be applied.

  Next, processing when external terminal devices 600B to 600D that are not included in the gateway device GW start communication with a specific IoT device connected to the downstream side of the gateway device GW will be described. Here, using the external terminal device 600B (smartphone), a user who is a resident of the home H communicates with the IoT devices 701 to 705 installed in the home H from the outside, and performs a desired operation. A specific processing procedure for the case of performing control will be described.

  First, the case where the network communication system shown in FIG. 22 is a system using the first embodiment of the basic invention of the prior application described in §1 will be described. In this case, terminal devices 600A to 600D have a configuration equivalent to that of terminal device 200 shown in FIG. 2, and connection mediating device 500 has a configuration equivalent to that of connection mediating device 100 shown in FIG. A communication session between terminal devices is established according to the procedure shown in FIG.

  For example, consider the procedure when the user gives an operation instruction to the IoT device 702 (air conditioner) installed in the home H using the external terminal device 600B (smartphone) from outside. In this case, the user starts a remote operation application program (a program for remotely controlling the air conditioner) incorporated in the external terminal device 600B, and inputs a desired operation instruction for the air conditioner. Then, the application program sends a communication request S1 with the external terminal device 600B as the communication source and the internal terminal device 600A as the communication destination to the communication request reception unit (corresponding to 220A in FIG. 4) in the external terminal device 600B. give.

  Then, based on the communication request S1, the connection mediation request unit (corresponding to 210A in FIG. 4) in the external terminal device 600B specifies the internal terminal device 600A included in the gateway device GW as a communication destination. The connection mediation request S2 including the communication destination specifying information (information indicating the terminal ID “0110”) is transmitted to the connection mediating apparatus 500. The connection mediating apparatus 500 refers to the address table T, and determines the location address “AD11” associated with the terminal ID “0110” specified by the communication destination specifying information included in the connection mediation request S2. A communication destination address is returned to the communication start request unit (corresponding to 240A in FIG. 4) in the external terminal device 600B (corresponding to S4 in FIG. 4).

  Subsequently, the communication start request unit (corresponding to 240A in FIG. 4) in the external terminal device 600B accesses the communication destination address “AD11” (internal terminal device 600A) returned in response to the connection mediation request S2. A communication start request S5 is made. Then, the communication destination session establishment unit (corresponding to 230B in FIG. 4) in the internal terminal device 600A transmits a communication start acceptance confirmation S6 to the communication source external terminal device 600B in response to the communication start request S5. Then, a communication session is established with the communication source external terminal device 600B, and communication (corresponding to S7 in FIG. 4) is started.

  On the other hand, the communication source session establishment unit (corresponding to 260A in FIG. 4) of the external terminal device 600B serving as the communication source communicates with the communication destination session establishment unit (corresponding to 230B of FIG. 4) of the internal terminal device 600A (see FIG. 4). 4 S7). Specifically, the communication source session establishment unit (corresponding to 260A in FIG. 4) of the external terminal device 600B serving as a communication source transmits a specific IoT device (here) as a final communication destination to the internal terminal device 600A. In the case of the example shown in FIG. 4, the data for the IoT device to be transmitted to the air conditioner of the IoT device 702 (in the case of the example shown here, operation instruction data for the air conditioner) and device specifying information for specifying the specific IoT device are included Send communication data.

  Thus, the communication data transmitted from the external terminal device 600B to the internal terminal device 600A is data indicating a desired operation instruction for the air conditioner. Such a data transmission procedure is as already described in §1. In this way, data transmission from the external terminal device 600B to the internal terminal device 600A is performed through mediation processing by the connection mediating device 500. Of course, in order to perform such mediation processing, the terminal IDs and location addresses of the internal terminal device 600A and the external terminal device 600B need to be registered in advance in the address table T in the connection mediating device 500. is there.

  Eventually, data indicating a desired operation instruction for the air conditioner has reached the internal terminal device 600A in the gateway device GW as communication data. When the gateway device GW receives such communication data, the device identification information (information for identifying the air conditioner of the IoT device 702 in the example shown here) and the data for the IoT device (shown here) are received from the communication data. In the case of the example, the operation instruction data for the air conditioner) is extracted, and the extracted data addressed to the IoT device is distributed to the IoT device 702 (air conditioner) specified by the extracted device specifying information. Thus, the operation instruction transmitted from the user by the user reaches the IoT device 702 (air conditioner) that is the final destination. Then, when the air conditioner executes the operation instruction, remote control of the air conditioner is performed.

  Next, the case where the network communication system shown in FIG. 22 is a system using the second embodiment of the basic invention of the prior application described in §2 will be described. In this case, the terminal devices 600A to 600D have a configuration equivalent to the terminal device 400 shown in FIG. 7, and the connection mediating device 500 has a configuration equivalent to the connection mediating device 300 shown in FIG. A communication session between terminal apparatuses is established according to the procedure shown in FIG.

  Here again, consider a procedure in the case where the user gives an operation instruction to the IoT device 702 (air conditioner) installed in the home H using the external terminal device 600B (smartphone) from outside. In this case, the user starts a remote operation application program (a program for remotely controlling the air conditioner) incorporated in the external terminal device 600B, and inputs a desired operation instruction for the air conditioner. Then, the application program sends a communication request S11 with the external terminal device 600B as the communication source and the internal terminal device 600A as the communication destination to the communication request reception unit (corresponding to 420B in FIG. 8) in the external terminal device 600B. give.

  Then, based on the communication request S11, the connection mediation request unit (corresponding to 410B in FIG. 8) in the external terminal device 600B specifies the internal terminal device 600A included in the gateway device GW as a communication destination. The connection mediation request S12 including the communication destination specifying information (information indicating the terminal ID “0110”) is transmitted to the connection mediating apparatus 500. By referring to the address table T, the connection mediating apparatus 500 refers to the location address “AD11” (internal) associated with the terminal ID “0110” specified by the communication destination specifying information included in the connection mediation request S12. The location address “AD12” associated with the terminal ID “0120” in the external terminal device 600B of the communication source that has transmitted the connection mediation request S12 is transmitted as the communication source address to the address of the terminal device 600A) ( This corresponds to S14 in FIG.

  Subsequently, the communication start request unit (corresponding to 440A in FIG. 8) in the internal terminal device 600A accesses the communication source address “AD12” (external terminal device 600B) transmitted in response to the connection mediation request S12. A communication start request S15 is performed. Then, the communication source session establishment unit (corresponding to 430B in FIG. 8) in the external terminal device 600B transmits a communication start acceptance confirmation S16 to the communication destination internal terminal device 600A in response to the communication start request S15. Then, a communication session is established with the communication destination internal terminal device 600A and communication (corresponding to S17 in FIG. 8) is started.

  Specifically, the communication source session establishment unit (corresponding to 430B in FIG. 8) of the external terminal device 600B serving as a communication source sends a specific IoT device (here) as a final communication destination to the internal terminal device 600A. In the case of the example shown in FIG. 4, the data for the IoT device to be transmitted to the air conditioner of the IoT device 702 (in the case of the example shown here, operation instruction data for the air conditioner) and device specifying information for specifying the specific IoT device are included Send communication data.

  On the other hand, the communication destination session establishment unit (corresponding to 460A in FIG. 8) of the internal terminal device 600A as the communication destination communicates with the communication source session establishment unit (corresponding to 430B of FIG. 8) of the external terminal device 600B (see FIG. 8 S17). Thus, communication between them is started.

  Here, the communication data transmitted from the external terminal device 600B to the internal terminal device 600A is data indicating a desired operation instruction for the air conditioner. Such a data transmission procedure is as already described in Section 2. In this way, data transmission from the external terminal device 600B to the internal terminal device 600A is performed through mediation processing by the connection mediating device 500. Of course, in order to perform such mediation processing, the terminal IDs and location addresses of the internal terminal device 600A and the external terminal device 600B need to be registered in advance in the address table T in the connection mediating device 500. is there.

  Eventually, data indicating a desired operation instruction for the air conditioner has reached the internal terminal device 600A in the gateway device GW as communication data. When the gateway device GW receives such communication data, the device identification information (information for identifying the air conditioner of the IoT device 702 in the example shown here) and the data for the IoT device (shown here) are received from the communication data. In the case of the example, the operation instruction data for the air conditioner) is extracted, and the extracted data addressed to the IoT device is distributed to the IoT device 702 (air conditioner) specified by the extracted device specifying information. Thus, the operation instruction transmitted from the user by the user reaches the IoT device 702 (air conditioner) that is the final destination. Then, when the air conditioner executes the operation instruction, remote control of the air conditioner is performed.

  The procedure for transmitting an operation instruction from the external terminal device 600B (smartphone) to the IoT device 702 (air conditioner) has been described above. However, the procedure for transmitting an operation instruction to other IoT devices 701, 703 to 705 is also described. It is the same. Of course, the procedure for transmitting an operation instruction from the external terminal device 600C (personal computer) to a specific IoT device is the same. The same applies to the procedure for spontaneous push-type distribution of update data from the external terminal device 600D (update server) to a specific IoT device and the procedure for pull-type distribution in response to a request from the IoT device.

  In this way, in the network communication system shown in FIG. 22, communication from the external terminal device 600B to the internal terminal device 600A is performed using the prior invention basic invention described in §1 or §2. For this reason, since intermediary processing by the connection mediating apparatus 500 is always required when communication between terminals is started, communication by this network communication system is possible only for terminal apparatuses registered in the address table T in advance. It will be limited in between.

  Therefore, access from an unauthorized terminal device that is not registered in the address table T to the internal terminal device 600A (gateway device GW) is excluded, and unauthorized access to each IoT device is also excluded. For example, when downloading an updater in a pull-type distribution form, even if a cracker plans a DNS spoofing attack and is tricked to lead to an unauthorized terminal device 19 instead of a legitimate update server 13, Since the mediation device 500 does not mediate connection to the unauthorized terminal device 19, it is possible to prevent a situation in which a fake updater is received. Thus, according to this network communication system, since communication from the Internet side to the IoT device side can be restricted in particular, sufficient security is ensured even for an inexpensive IoT device assuming personal use. It will be possible to connect to the Internet.

<<< §7. Specific structure of communication data in the present invention >>>
In §6, the configuration of the basic embodiment of the present invention is shown with reference to FIG. 22, and an operation instruction is transmitted from the external terminal device 600B (smart phone) to a specific IoT device 702 (air conditioner). Explained the specific procedure. Here, a specific structure of communication data transmitted from the external terminal device to the internal terminal device will be described in detail, and a specific distribution method of data addressed to the IoT device by the gateway device GW will be described.

<7.1 Basic communication data structure>
FIG. 23 is a diagram illustrating a basic configuration example of communication data Q10 transmitted from the external terminal devices 600B to 600D to the internal terminal device 600A in the network communication system illustrated in FIG. In the example shown here, the communication data Q10 is in the form of an IP packet having a data structure according to the IP protocol. In communication via the Internet, packet communication using IP packets is generally performed, and it is preferable to use IP packets as communication data Q10 when implementing the present invention. In practice, the communication data Q10 composed of this IP packet may be transmitted based on a protocol on the transport layer such as UDI or TCP.

  As shown in FIG. 23, this communication data Q10 (IP packet) is composed of an IP header portion Q11 and an IP data portion Q12. The IP header portion Q11 includes a transmission source address Q111 and a transmission destination address Q112. This IP packet is transmitted from the external terminal devices 600B to 600D indicated by the transmission source address Q111 to the internal terminal indicated by the transmission destination address Q112. Sent to device 600A. For example, in the example shown in FIG. 22, in the case of the communication data Q10 transmitted from the external terminal device 600B (smart phone) to the internal terminal device 600A (gateway device GW), the IP header portion Q11 includes the external terminal as the transmission source address Q111. The location address “AD12” of the device 600B is recorded, and the location address “AD11” of the internal terminal device 600A is recorded as the transmission destination address Q112.

  On the other hand, the IP data portion Q12 includes device specifying information Q121 for specifying an IoT device, and IoT device-addressed data Q122 to be transmitted to the IoT device. The IoT device-addressed data Q122 is data such as operation instruction data and update data given to a specific IoT device, and the device specifying information Q121 is information specifying the IoT device that is the final destination of the data. .

  As described above, the communication data Q10 is received by the internal terminal device 600A in the gateway device GW. The gateway device GW, based on the device identification information Q121 and the IoT device address data Q122 included in the IP data portion Q12 of the received communication data Q10, determines the IoT device address data Q122 by the device specification information Q121. Process to distribute to the device.

  In the case of the basic embodiment shown in FIG. 22, an IoT device registration table TT is stored in the gateway device GW in order to distribute the IoT device address data Q122. As illustrated in FIG. 24, the IoT device registration table TT indicates device identification information Q121 on each of the IoT devices 701 to 705 connected to the downstream side of the gateway device GW and an access method to the IoT device. It is the table which matched access method information.

  When the gateway device GW receives the communication data Q10, the gateway device GW uses the access method indicated by the access method information corresponding to the device specifying information Q121 extracted from the received communication data Q10 by referring to the IoT device registration table TT. Then, the delivery destination IoT devices 701 to 705 are accessed, and the IoT device-addressed data Q122 extracted from the received communication data Q10 is delivered to the delivery destination IoT devices 701 to 705.

  In the IoT device registration table TT illustrated in FIG. 24, information including the manufacturer name, product model number, and product number of the IoT device is registered as the device identification information Q121. Here, the manufacturer name is the name of a company that manufactures or sells the IoT device, and an abbreviation or a company code may be used. The product model number is a model number assigned by the operator to the IoT device, and the product number is a number for each individual product assigned by the operator to the IoT device. By using a combination of these three pieces of information, unique device specifying information Q121 can be defined for each IoT device.

  Of course, the configuration of the device identification information Q121 is not limited to this embodiment, and at least information that can distinguish a plurality of IoT devices connected to the downstream side of the same gateway device GW from each other. The information can be used as the device identification information Q121. However, if the device identification information Q121 is configured by a combination of three pieces of information as in the illustrated embodiment, unique device identification information can be defined for each IoT device in the world, and which manufacturer Since it is possible to recognize which product and which individual device, it is preferable that the device identification information Q121 is configured by a combination of such three pieces of information.

  On the other hand, in the IoT device registration table TT illustrated in FIG. 24, information including a communication standard for performing communication with the IoT device and a unique address for performing access according to the communication standard is registered as access method information. ing. In the network communication system shown in FIG. 22, communication between external terminal apparatuses 600B to 600D and internal terminal apparatus 600A (gateway apparatus GW) is performed according to the IP protocol as described above, and communication data Q10 constitutes an IP packet. Will do. On the other hand, communication between the gateway device GW and each of the IoT devices 701 to 705 connected to the downstream side of the gateway device GW is not necessarily performed according to the IP protocol, and communication based on various communication standards can be performed. It is.

  In the IoT device registration table TT shown in FIG. 24, three types of communication standards, such as WiFi, Ethernet (registered trademark), and short-range wireless communication (for example, Bluetooth (registered trademark)), are exemplified. However, for example, communication using infrared rays may be used. When WiFi or Ethernet (registered trademark) is used as a communication standard, communication according to the IP protocol is usually used, but of course, other protocols may be used.

  In fact, the communication standard and communication protocol of the operation instruction signal for remotely operating each IoT device are arbitrarily determined by the manufacturer of the IoT device. Therefore, if a communication means (hardware and software) based on a specific communication standard or a specific communication protocol adopted by each of these IoT devices is provided in the gateway device GW, it can be used for all IoT devices. Individual communication is possible.

  For each IoT device, the unique address registered together with the communication standard is an address required when accessing the IoT device according to the communication standard. For example, if access is made using the IP protocol using WiFi or Ethernet (registered trademark), the IP address assigned to the IoT device to be accessed can be registered as a unique address, and Bluetooth (registered trademark) can be registered. In the case of performing access using short-range wireless communication such as the above, it is possible to register an address determined by a pairing process performed in advance between the IoT device and the gateway device GW as a unique address. Of course, the MAC address of the IoT device may be registered as a unique address.

  When a user installs a new IoT device in the home H, the user performs an operation of registering device identification information Q121 and access method information on the IoT device in the IoT device registration table TT in the gateway device GW. To. For example, the second line of the IoT device registration table TT shown in FIG. 24 shows an example in which the air conditioner 702 of company Y is registered as an IoT device. Specifically, for the air conditioner 702, as the device identification information Q121, information including the manufacturer name “Company Y”, the product model number “YA-456”, and the product number “456789” is registered, and the communication standard “WiFi” is registered as the access method information. ”, An example in which information of a unique address“ AD702 ”is registered is shown.

  Since it is complicated for the user to manually register such information, practically, a dedicated registration program is prepared in each IoT device, the gateway device GW, or both. It is preferable that registration in the IoT device registration table TT is automatically performed by starting the registration program.

  In addition, in order to control the air conditioner 702 using the external terminal device 600B (smart phone) or 600C (personal computer) from outside, an internal terminal device incorporated in the gateway device GW in the external terminal devices 600B and 600C. It is necessary to register the terminal ID “0110” of 600A and the device identification information Q121 for identifying the air conditioner 702. Therefore, when the user installs the air conditioner 702 of company Y as a new IoT device, the device identification information Q121 is registered in the IoT device registration table TT in the gateway device GW and the external terminal devices 600B and 600C are registered. Thus, it is necessary to register the terminal ID “0110” of the internal terminal device 600A and the device identification information Q121 of the air conditioner 702.

  In practice, it is preferable that the registration operation for the external terminal device is automatically performed using a dedicated registration program. Actually, in order to remotely operate IoT devices such as the air conditioner 702 by the external terminal devices 600B and 600C, a dedicated remote operation program is incorporated into the external terminal devices 600B and 600C. As part of the program installation process, the terminal ID “0110” of the internal terminal device 600A and the device identification information Q121 of the air conditioner 702 may be incorporated together.

  Then, for example, when a remote operation program for remotely operating the air conditioner 702 is installed in the external terminal device 600B (smartphone), the terminal ID “0110” of the internal terminal device 600A and the manufacturer name “ Device identification information Q121 of “Company Y”, product model number “YA-456”, and product number “456789” is incorporated into the external terminal device 600B.

  When the user operates the external terminal device 600B from outside and controls the air conditioner 702 in the home H, the user activates the installed remote operation program and sets a desired operation instruction (for example, a room temperature of 28 °). (Operation instruction to turn on the cooling function) so as to be maintained at C. Then, from the remote operation program, communication requests S1 and S11 with the internal terminal device 600A as the communication destination are made to the communication request receiving units 220 and 420 in the external terminal device 600B (see FIGS. 4 and 8). Connection mediation requests S2 and S12 including the terminal ID “0110” of the internal terminal device 600A are made from the connection mediation request units 210 and 410 to the connection mediation device 500.

  Communication S7, S17 between the communication source session establishment units 260, 430 of the external terminal device 600B and the communication destination session establishment units 230, 460 of the internal terminal device 600A by mediation processing based on the connection mediation requests S2, S12. Is already described.

  In communications S7 and S17, communication data Q10 as shown in FIG. 23 is transmitted. The communication data Q10 is created by the communication source session establishment units 260 and 430 of the external terminal device 600B. For this purpose, an IP header part Q11 and an IP data part Q12 as shown in the figure may be created. Here, the IP header portion Q11 may be created as data including the IP address “AD12” of the external terminal device 600B as the transmission source address Q111 and the IP address “AD11” of the internal terminal device 600A as the transmission destination address Q112. . Further, the IP data part Q12 includes IoT device-addressed data Q122 (operation instruction data for the air conditioner 702) and device identification information Q121 (manufacturer name, product model number, product for the air conditioner 702) notified from the remote operation program for the air conditioner 702. Number).

  Eventually, the communication data Q10 shown in FIG. 23 is created by performing a process of encapsulating the IoT device address data Q122 in an IP packet. The IP packet created in this way is transmitted toward the transmission destination address Q112 (location address of the internal terminal device 600A) in the IP header portion Q11. Since the IoT device-addressed data Q122 is encapsulated and incorporated in the communication data Q10, the communication data Q10 itself behaves as an IP packet regardless of the structure of the IoT device-addressed data Q122. The IP packet arrives at the internal terminal device 600A in the state of the IP packet.

  Of course, there may be a case where the data Q122 addressed to the IoT device itself constitutes an IP packet (such as when the IoT device requests an operation instruction in the form of an IP packet). In this case, the IP packet constituting the IoT device-addressed data Q122 is encapsulated in the IP packet constituting the communication data. The former is an IP packet having the gateway device GW as a transmission source and the IoT device (air conditioner 702) as a transmission destination, whereas the latter is an external terminal device 600B as a transmission source and the internal terminal device 600A as a transmission destination. It becomes an IP packet.

  When such communication data Q10 arrives at the internal terminal device 600A, the gateway device GW extracts the device specifying information Q121 and the IoT device-addressed data Q122 from the IP data unit Q12. The IoT device-addressed data Q122 is operation instruction data for a specific IoT device (in the example shown here, the air conditioner 702), and therefore can be directly transmitted to the specific IoT device. The gateway device GW recognizes the access method information about the IoT device (air conditioner 702) specified by the extracted device specifying information Q121 by referring to the IoT device registration table TT illustrated in FIG. 24, and the access method information The IoT device is accessed according to the above, and the data Q122 addressed to the IoT device is transmitted. In the case of the illustrated example, the IoT device-addressed data Q122 is transmitted to the air conditioner 702 indicated by the unique address AD702 by WiFi.

  The specific structure of the communication data Q10 used when the air conditioner 702 is remotely controlled by the external terminal device 600B (smartphone) and the distribution method of the IoT device-addressed data Q122 by the gateway device GW have been described above. The external terminal device 600C The same applies when the air conditioner 702 is remotely controlled by a (personal computer). Further, the external terminal device 600D (update server) does not transmit an operation instruction for remotely controlling an IoT device such as the air conditioner 702, but plays a role of transmitting update data for updating firmware incorporated in the IoT device. Therefore, the data addressed to the IoT device encapsulated in the communication data Q10 addressed to the internal terminal device 600A from the external terminal device 600D is an updater or an update program.

<7.2 Structure of encrypted communication data>
Here, a modification example in which communication data is encrypted in order to further improve the security of communication via the Internet will be described. As described above, the communication data Q10 shown in FIG. 23 is transmitted from the external terminal device 600B to the internal terminal device 600A via the Internet. May be used. In particular, since the data addressed to the IoT device is operation instruction data or update data given to the destination IoT device, the analysis by the cracker is a security threat. The modification described here improves communication security by encrypting data addressed to the IoT device.

  FIG. 25 is a block diagram illustrating a basic principle of encrypting communication between the external terminal devices 600B to 600D and the internal terminal device 600A in the network communication system illustrated in FIG. The upper part of the figure shows the encryption process performed on the external terminal apparatuses 600B to 600D side, and the lower part of the figure shows the decryption process performed on the gateway apparatus GW side. A feature of the encryption process and decryption process performed here is that unique data U stored in the destination IoT device is used as the encryption key and the decryption key.

  For example, in the embodiment shown in FIG. 22, when the external terminal device 600B transmits IoT device-addressed data Q122 (operation instruction data for the air conditioner) to the air conditioner 702, first, the external terminal device 600B has the upper part of FIG. As shown, encryption processing using the unique data U stored in the air conditioner 702 as an encryption key is executed on the IoT device-addressed data Q122 to create IoT device-addressed encrypted data Q122C. The encrypted data Q122C addressed to the IoT device may be transmitted to the internal terminal device 600A (gateway device GW).

  On the other hand, in the gateway apparatus GW that has received the encrypted data Q122C addressed to the IoT device, as shown in the lower part of FIG. 25, the decryption key is used to decrypt the unique data U stored in the air conditioner 702 with respect to the encrypted data Q122C addressed to the IoT device. It is only necessary to execute the decryption process used as the above and restore the data Q122 addressed to the IoT device. The IoT device-addressed data Q122 restored in this way is distributed from the gateway device GW to the air conditioner 702 in the same manner as in the basic embodiment described so far.

  FIG. 26 is a diagram showing a basic configuration example of the encrypted communication data Q20 transmitted from the external terminal device 600B to the internal terminal device 600A based on the basic principle shown in FIG. Similar to the communication data Q10 shown in FIG. 23, the encrypted communication data Q10C shown in FIG. 26 takes the form of an IP packet having a data structure in accordance with the IP protocol, and includes an IP header part Q11 and an IP data part Q12C. It is comprised by. Here, the IP header part Q11 includes a source address Q111 (in this example, the location address “AD12” of the external terminal device 600B) and a destination address Q112 (in this example, the location address of the internal terminal device 600A). "AD11"). This is the same as the communication data Q10 shown in FIG.

  On the other hand, the IP data part Q12C of the encrypted communication data Q10C shown in FIG. 26 includes device specifying information Q121 for specifying the IoT device and encrypted data Q122C addressed to the IoT device to be transmitted to the IoT device. After all, the difference between the communication data Q10 shown in FIG. 23 and the encrypted communication data Q10C shown in FIG. 26 is that the former IP data portion Q12 includes the IoT device-addressed data Q122, whereas the latter IP data. The part Q12C only includes encrypted data Q122C addressed to the IoT device. In short, in the encrypted communication data Q10C shown in FIG. 26, the IoT device-addressed encrypted data Q122C is encapsulated in the IP packet.

  As described above, this IoT device-addressed encrypted data Q122C is created by encryption processing using the unique data U stored in the destination IoT device as an encryption key with respect to the IoT device-addressed data Q122. Yes, after this encrypted communication data Q10C reaches the internal terminal device 600A, it is restored to the original data IoT device data Q122 through a decryption process by the gateway device GW. In the decryption process, the same data U used as the encryption key during the encryption process is used as the decryption key.

  Here, the data U used as the encryption key and the decryption key may be any data as long as it is unique data stored in the destination IoT device, but the encryption performed by the external terminal device 600B. Since it is used for the process and the decoding process performed by the gateway device GW, the data needs to be usable by the external terminal device 600B and the gateway device GW.

  Specifically, for example, the CPU serial number and MAC address of the IoT device can be used as unique data U, but the data U can be used from both the external terminal device 600B and the gateway device GW. It is necessary to keep. In order to make it usable from the external terminal device 600B, the unique data U may be registered together when the device specifying information Q121 is registered in the external terminal device 600B. Further, in order to make it available from the gateway device GW, for example, unique data U is registered in the IoT device registration table TT shown in FIG. 24 together with the device identification information Q121 and the access method information. Good. When the gateway device GW performs the decryption process, the data U used as a decryption key can be identified by the device identification information Q121 included in the IP data portion Q12C of the encrypted communication data Q10C.

  As described above, when the unique data U stored in the destination IoT device is used as the encryption key and the decryption key, in addition to the security merit obtained by the encryption, it can be confirmed that the correct destination has been reached. A secondary merit is also obtained. For example, in the case of the above-described example, the encrypted communication data Q10C is transmitted from the external terminal device 600B to the internal terminal device 600A, so the correct counterpart is the internal terminal device 600A. However, if it is transmitted to the wrong internal terminal device 600E (a terminal device incorporated in another gateway device) for some reason, the internal terminal device 600E receives the received encrypted communication data Q10C. Can be recognized as an erroneous transmission.

  This is because the correct decryption key is not stored in the internal terminal device 600E, and thus the encrypted communication data Q10C that has been erroneously transmitted cannot be decrypted into the correct state. In other words, the internal terminal device 600A that is the correct counterpart can correctly decrypt the encrypted communication data Q10C included in the received encrypted communication data Q10C, and the received encrypted communication data Q10C It can be confirmed that the communication data is addressed to itself.

  The data used as the encryption key and the decryption key does not necessarily need to be the unique data U itself stored in the destination IoT device, and may be derived data that is uniquely obtained from the data U. It doesn't matter. For example, when the CPU serial number or MAC address of the IoT device is used as the unique data U, the encryption key and the decryption key do not need to be the CPU serial number or the MAC address itself. It may be derived data that is uniquely determined based on the CPU serial number or MAC address.

  In short, if the modified example in which the encrypted communication data Q10C is transmitted based on the basic principle shown in FIG. 25 is implemented, the communication source session establishment units 260 and 430 of the external terminal device 600B will communicate with the communication destination session of the internal terminal device 600A. When communication S7, S17 is performed with respect to the establishing units 230, 460, the following processing may be performed.

  First, when the communication source session establishment units 260 and 430 of the external terminal device 600B transmit predetermined IoT device-addressed data Q122 to a specific IoT device 702 that is a destination, The encrypted data Q122C addressed to the IoT device is created by performing encryption processing using the unique data U stored in the IoT device 702 or the derived data uniquely obtained from the data U as an encryption key. Then, the encrypted communication data Q10C (see FIG. 26) including the created IoT device-addressed encrypted data Q122C and device specifying information Q121 for specifying the specific IoT device 702 is transmitted to the internal terminal device 600A. Just send it.

  On the other hand, when the gateway device GW including the internal terminal device 600A receives the encrypted communication data Q10C, the gateway device GW extracts the device specifying information Q121 and the IoT device-addressed encrypted data Q122C from the encrypted communication data Q10C. The IoT device is then decrypted using the unique data U stored in the IoT device 702 identified by the extracted device identification information Q121 or derived data uniquely obtained from the data U as a decryption key. The address data Q122 is restored. Then, the restored IoT device-addressed data Q122 may be distributed to the IoT device 702 specified by the extracted device specifying information Q121.

<<< §8. Valid port restriction >>
Here, as a modification of the basic embodiment of the present invention described in §6, a method for further improving security by limiting the effective ports for the internal terminal device 600A will be described.

  FIG. 15 shows an embodiment in which terminal devices 200E, 200F, and 200G are connected to a network N via a router R. In this way, the terminal device used in the present invention can be accessed by adding the port number to the IP address regardless of the presence or absence of the router R. Normally, a port number assigned to a terminal device is used to distinguish an application program operating in the terminal device, and received data is delivered to an application program corresponding to the designated port number.

  The modification of the present invention described here restricts effective ports while adopting an operation of adding the port number to the IP address to the internal terminal apparatus 600A in the basic embodiment shown in FIG. Thus, the security is further improved. As already described in §6, the internal terminal device 600A in the present invention functions exclusively as a component of the gateway device GW, and the role thereof is each IoT device connected to the downstream side of the gateway device GW. 701 to 705 are connected to the Internet N on the upstream side. For this reason, the communication data Q10 or the encrypted communication data Q10C received by the internal terminal device 600A is always delivered to a dedicated application program incorporated in the gateway device GW.

  Accordingly, when accessing the internal terminal device 600A from the upstream side, when the operation is performed by adding the port number to the IP address, the port number indicates a dedicated application program that functions as the gateway device GW. It will be a number. Therefore, in the modification described here, the internal terminal device 600A sets a specific port as a valid port and connects the current valid port at a predetermined cycle or when the valid port setting is changed. Processing for notifying the intermediary device 500 and receiving only IP packets for which the port number corresponding to the valid port is designated among IP packets transmitted via the network N and rejecting other IP packets To do.

  A plurality of effective ports may be set at a certain point in time, but in practice, it is preferable to always set only one port as an effective port. As described above, all the data received by the internal terminal device 600A need only be delivered to a single application program that functions as the gateway device GW, so only one port corresponding to the single application program is required. It is sufficient to set as a valid port. The valid port number may be changed as necessary. For example, the port indicated by the port number P13 is set as a valid port at a certain time, but the port indicated by the port number P14 is set as a valid port at the next time.

  The current effective port is notified from the internal terminal device 600A to the connection mediating device 500 at a predetermined cycle or when the setting of the effective port is changed. In response to this notification, the connection mediating apparatus 500 records the port number of the valid port in the address table T. The address table in which the port number is recorded together with the IP address as the location address is in the form of address tables T41 and T42 illustrated in FIG.

  When connection mediation device 500 receives a connection mediation request from external terminal devices 600B-600D with internal terminal device 600A as the communication destination, mediation using an address including the port number of the valid port as the communication destination or communication source address. Process. That is, the port number of the valid port is notified together with the IP address of the internal terminal device 600A as the communication destination or the communication source address. Accordingly, the external terminal devices 600B to 600D access the internal terminal device 600A using the IP address and the port number of the valid port. Specifically, an IP packet designating an IP address and a port number is transmitted.

  When an IP packet is transmitted via the network N, the internal terminal device 600A receives this when the IP packet designates a port number corresponding to a valid port, If the port number is specified, processing for rejecting the port number is performed. In this way, if the valid port is restricted in the internal terminal device 600A, since IP packets other than the IP packet specifying the port number of the valid valid port notified from the connection mediating device 500 are rejected, the unauthorized terminal device Can be prevented from reaching the IP packet transmitted from the. In particular, if only a single port is set as a valid port, it is possible to effectively eliminate the arrival of an IP packet from an unauthorized terminal device.

<<< §9. Transmission from an IoT device to an external terminal device >>>
So far, in the network communication system according to the basic embodiment of the present invention shown in FIG. 22, the IoT device address data Q122 is sent from any external terminal device 600B to 600D to any IoT device 701 to 705 in the home H. Although the transmission procedure has been described, of course, data (hereinafter referred to as terminal device-addressed data Q222) addressed to any external terminal device 600B-600D from any IoT device 701-705 (hereinafter referred to as a transmission source). It is also possible to transmit.

  Hereinafter, a procedure when a specific IoT device in the home H communicates with a specific external terminal device will be described. Here, specifically, a case where the IoT device 702 (air conditioner) transmits data Q222 (for example, data for notifying the current temperature around the air conditioner) to a predetermined terminal device to the external terminal device 600B (smart phone) is considered. Let's try.

  In this case, first, a terminal for the IoT device 702 to identify the external terminal device 600B as a transmission destination with respect to the communication request reception unit (corresponding to 220A in FIG. 4 or 420B in FIG. 8) of the internal terminal device 600A. The device specification information Q220, device specification information Q221 specifying itself (IoT device 702), and terminal device-addressed data Q222 to be transmitted to the external terminal device 600B are transmitted as communication requests S1 and S11. Here, as the terminal device specifying information Q220, for example, the terminal ID “0120” of the external terminal device 600B may be used. Further, as the device specifying information Q221 for specifying itself, for example, device specifying information Q121 (manufacturer name, product model number, product number) registered in the IoT device registration table TT shown in FIG. 24 may be used.

  When the communication request accepting unit of the internal terminal device 600A accepts the communication requests S1 and S11, the connection mediation request unit (corresponding to 210A in FIG. 4 or 410B in FIG. 8) of the internal terminal device 600A Connection brokerage requests S2 and S12 including communication destination identification information (terminal ID “0120” of the external terminal apparatus 600B) whose communication destination is the external terminal apparatus 600B identified by the identification information Q220 are transmitted to the connection brokerage apparatus 500. . When the terminal ID “0120” of the external terminal device 600B is used as the terminal device specifying information Q220, this may be used as it is as the communication destination specifying information.

  Here, when this network communication system is constructed using the first embodiment of the basic invention of the prior application shown in FIG. 4, the connection mediating apparatus 500 determines whether or not the internal terminal apparatus responds to the connection mediation request S2. A communication destination address “AD12” is returned to the communication start request unit 600A (corresponding to 240A in FIG. 4). Therefore, when the communication start request unit of the internal terminal device 600A accesses the returned communication destination address “AD12” and makes the communication start request S5, the communication destination session establishment unit (230B in FIG. 4) of the external terminal device 600B. The communication start acceptance confirmation S6 is transmitted. Thus, communication S7 is started between the communication source session establishment unit (corresponding to 260A in FIG. 4) of the internal terminal device 600A and the communication destination session establishment unit (corresponding to 230B of FIG. 4) of the external terminal device 600B. The

  On the other hand, when this network communication system is constructed using the second embodiment of the basic invention of the prior application shown in FIG. 8, the connection mediating device 500 responds to the connection mediation request S12 and the external terminal device 600B. The communication source address “AD11” is returned to the communication start request unit (corresponding to 440A in FIG. 8). Therefore, when the communication start request unit of the external terminal device 600B accesses the transmitted communication source address “AD11” and makes the communication start request S15, the communication source session establishment unit (430B in FIG. 8) of the internal terminal device 600A. The communication start acceptance confirmation S16 is transmitted. Thus, communication S17 is started between the communication source session establishment unit (corresponding to 430B in FIG. 8) of the internal terminal device 600A and the communication destination session establishment unit (corresponding to 460A of FIG. 8) of the external terminal device 600B. The

  Thus, when the communication session between the two is established and communication S7 or communication S17 is performed between the two, the device identification information Q221 and the terminal device-addressed data Q222 are transmitted from the internal terminal device 600A to the external terminal device 600B. The communication data Q20 including “” may be transmitted.

  As the form of communication data Q20, it is preferable to adopt the form of an IP packet having a data structure according to the IP protocol. FIG. 27 is a diagram illustrating a configuration example of communication data Q20 having an IP packet format. In practice, the communication data Q20 composed of this IP packet may be transmitted based on a protocol on the transport layer such as UDI or TCP.

  The data structure of communication data Q20 (IP packet) shown in FIG. 27 is substantially the same as the data structure of communication data Q10 (IP packet) shown in FIG. That is, the communication data Q20 includes an IP header part Q21 and an IP data part Q22. The IP header part Q21 includes a transmission source address Q211 and a transmission destination address Q212. This IP packet is transmitted from the internal terminal device 600A indicated by the transmission source address Q211 (location address “AD11”) to the transmission destination address Q212. It is transmitted toward the external terminal device 600B indicated by (location address “AD12”).

  Here, the location address “AD12” of the external terminal device 600B serving as the transmission destination address Q212 is determined by using the terminal device specifying information Q220 (terminal ID “0120”) transmitted from the IoT device 702 (air conditioner). This is obtained by a connection mediation request made to 500.

  On the other hand, the IP data portion Q22 includes device specifying information Q221 for specifying the IoT device 702 that is the original transmission source, and terminal device-addressed data Q222 to be transmitted to the external terminal device 600B (for example, current data around the air conditioner). Temperature notification data). These pieces of information are all created by the IoT device 702 and transmitted to the internal terminal device 600A. Internal terminal apparatus 600A creates communication data Q20 based on these pieces of information.

  In short, the internal terminal device 600A includes its own IP address as the transmission source address Q211 and the IP header portion Q21 including the IP address of the external terminal device 600B as the transmission destination address Q212, terminal device addressed data Q222, and device specifying information. By creating an IP packet Q20 having an IP data part Q22 including Q221, the terminal device-addressed data Q222 is encapsulated in the IP packet Q20, and this IP packet is used as communication data Q20 as an external terminal. Processing to transmit to the device 600B is performed.

  When such communication data Q20 arrives at the external terminal device 600B, the device specifying information Q221 and the terminal device-addressed data Q222 are extracted from the IP data part Q22 in the external terminal device 600B. Since the source address Q211 includes the location address of the internal terminal device 600A, it can be confirmed that the data Q222 addressed to the terminal device has been transmitted from the internal terminal device 600A. However, the source address Q211 does not include information indicating which IoT device the original transmission source is. Therefore, the external terminal device 600B can confirm that the original transmission source of the terminal device-addressed data Q222 is the IoT device 702 (air conditioner) by referring to the extracted device specifying information Q221.

  Thus, the terminal device-addressed data Q222 is transferred to a dedicated application program for the IoT device 702 (air conditioner) installed in the external terminal device 600B, and a predetermined process is executed. For example, when the terminal device-addressed data Q222 is data for notifying the current temperature around the air conditioner, a display indicating that the temperature has been notified is displayed on the display screen of the external terminal device 600B (smartphone) by the dedicated application program. Done.

  The example in which information is transmitted from the IoT device 702 (air conditioner) to the external terminal device 600B (smartphone) has been described above. However, the same applies to the case where information is transmitted from any IoT device to any external terminal device. For example, the external terminal device 600D is an update server that plays a role of providing update data to the IoT device, but when the update data is provided by push-type distribution, transmission from the external terminal device 600D to the IoT device is performed. It is enough to be received. On the other hand, when providing the updater by pull-type delivery, first, it is necessary to make an update data request from the IoT device to the external terminal device 600D. It is transmitted to the external terminal device 600D.

  In §7.2, based on the principle shown in FIG. 25, a modified example is described in which the encrypted communication data Q10C shown in FIG. 26 is transmitted instead of the communication data Q10 shown in FIG. This encryption method is also applicable to the communication data Q20 transmitted from the IoT device to the external terminal device.

  FIG. 28 is a diagram illustrating a configuration example of encrypted communication data used when information is transmitted from a specific IoT device to a specific external terminal device by applying such an encryption method. Like the communication data Q20 shown in FIG. 27, the encrypted communication data Q20C shown in FIG. 28 takes the form of an IP packet having a data structure according to the IP protocol, and includes an IP header part Q21 and an IP data part Q22C. It is comprised by. Here, the IP header portion Q21 includes a source address Q211 (in the above example, the location address “AD11” of the internal terminal device 600A) and a destination address Q212 (in the above example, the location address of the external terminal device 600B). “AD12”). This is the same as the communication data Q20 shown in FIG.

  On the other hand, the IP data part Q22C of the encrypted communication data Q20C shown in FIG. 28 includes device specifying information Q221 for specifying the IoT device and terminal device-addressed encrypted data Q222C to be transmitted to the external terminal device. After all, the difference between the communication data Q20 shown in FIG. 27 and the encrypted communication data Q20C shown in FIG. 28 is that the former IP data part Q22 includes the terminal device data Q222, whereas the latter IP data. The part Q22C only includes the encrypted data Q222C addressed to the terminal device. In short, in the encrypted communication data Q20C shown in FIG. 28, the encrypted data Q222C addressed to the terminal device is encapsulated in the IP packet.

  The terminal device-addressed encrypted data Q222C is obtained by performing encryption processing on the terminal device-addressed data Q222 using the unique data U stored in the IoT device that is the original transmission source as an encryption key. The gateway device GW will create it. After the terminal device-addressed encrypted data Q222C arrives at the external terminal device 600B, it is restored to the original terminal device-addressed data Q222 through a decryption process in the external terminal device 600B. In the decryption process, the same data U used as the encryption key during the encryption process is used as the decryption key.

  Here, the data U used as the encryption key and the decryption key may be any data as long as it is unique data stored in the IoT device as the transmission source, but the encryption performed by the gateway device GW. Since it is used for the process and the decoding process performed in the external terminal device 600B, the gateway device GW and the external terminal device 600B need to be usable data.

  Specifically, for example, the CPU serial number and MAC address of the IoT device can be used as unique data U, but the data U can be used from both the external terminal device 600B and the gateway device GW. It is necessary to keep. The specific method for doing so is as described in § 7.2. Further, the data used as the encryption key and the decryption key does not necessarily need to be the unique data U itself stored in the IoT device as the transmission source, and is derived data that is uniquely obtained from the data U. It doesn't matter. This point is also as already described in §7.2.

  Eventually, if a modified example in which transmission from the IoT device 702 to the external terminal device 600B is encrypted is performed, the communication source session establishment units 260 and 430 of the internal terminal device 600A perform the communication destination session of the external terminal device 600B. When communication S7, S17 is performed with respect to the establishing units 230, 460, the following processing may be performed.

  First, the gateway device GW including the internal terminal device 600A, with respect to the data Q222 addressed to the terminal device, is uniquely obtained from the unique data U stored in the IoT device 702 serving as the transmission source or from the data U By performing encryption processing using the data as an encryption key, encrypted data Q222C addressed to the terminal device is created. Then, the encrypted communication data Q20C (see FIG. 28) including the created terminal device-addressed encrypted data Q222C and device identification information Q221 may be transmitted to the external terminal device 600B.

  More specifically, the gateway device GW includes the IP header portion Q21 including the IP address of the internal terminal device 600A as the transmission source address Q211 and the IP address of the external terminal device 600B as the transmission destination address Q212, and the encryption addressed to the terminal device. By creating the IP packet Q20C having the IP data part Q22C including the data Q222C and the device specifying information Q221, the terminal device encrypted data Q222C is encapsulated in the IP packet Q20C. What is necessary is just to transmit with respect to the external terminal device 600B as encryption communication data Q20C.

  On the other hand, when receiving the encrypted communication data Q20C, the external terminal device 600B extracts the device specifying information Q221 and the terminal device-addressed encrypted data Q222C from the encrypted communication data Q20C. Then, the unique data U stored in the IoT device 702 specified by the extracted device specifying information Q221 or the derived data uniquely obtained from the data U is decrypted from the extracted terminal device-addressed encrypted data Q222C. The terminal-addressed data Q222 may be restored by performing a decryption process used as a key.

<<< §10. Specific Configuration of Gateway Device in the Present Invention >>
As described in §6, the gateway device GW shown in FIG. 22 includes the internal terminal device 600A, refers to the IoT device registration table TT, and distributes the received IoT device-addressed data Q122 to the destination IoT device. Perform the process. Here, a more specific configuration example of the gateway device GW will be described. The gateway devices GW and GW ′ described below can be configured by incorporating a dedicated program into the computer.

<10.1 Configuration Example of Basic Gateway Device>
FIG. 29 is a block diagram illustrating a specific configuration example of the gateway device GW illustrated in FIG. 22. As shown in the figure, this gateway device GW includes an internal terminal device 600A, an internal terminal mediation unit 610, and N units connected to the downstream side (N is a natural number: in the example shown in FIG. = 5 example) IoT devices 701 to 705 have N individual communication units 611 to 615 corresponding one-to-one.

  The individual communication units 611 to 615 have a function of performing mutual communication with the corresponding IoT devices 701 to 705 based on a predetermined communication standard. For example, the individual communication unit 611 is a dedicated component for mutual communication with the IoT device 701 (monitoring camera), and the individual communication unit 612 is a dedicated component for mutual communication with the IoT device 702 (air conditioner). It is. However, these N individual communication units 611 to 615 do not necessarily have to be individual devices having independent hardware, and a plurality of individual communication units share the same hardware device, and each is similar in terms of software. It may function as a separate component.

  For example, in the example of the IoT device registration table TT shown in FIG. 24, since the IoT device 701 (monitoring camera) and the IoT device 702 (air conditioner) use the same communication standard, the individual communication units 611 and 612 are It can be configured using the same WiFi communication device. However, the individual communication unit 611 is operated by software that performs mutual communication with the IoT device 701 using the unique address of the IoT device 701 (monitoring camera), and the individual communication unit 612 is operated by the IoT device 702 (air conditioner). The operation is performed by software that performs mutual communication with the IoT device 702 using the unique address.

  After all, when preparing an individual communication unit corresponding to the IoT device registration table TT shown in FIG. 24, in terms of hardware, the individual communication units 611 and 612 are configured by WiFi communication devices, and the individual communication units 613 and 614 are connected to the Ethernet. (Registered Trademark) Communication devices may be configured, and the individual communication unit 615 may be configured with short-range wireless communication devices. On the other hand, in terms of software, it is only necessary to perform communication to the unique address of the corresponding IoT device.

  On the other hand, the intermediary unit for internal terminal 610 includes an IoT device registration table TT ′ in which device identification information Q121 about each IoT device 701 to 705 is associated with individual communication units 611 to 615 corresponding to the IoT device. Is stored. The actual state of the IoT device registration table TT ′ is slightly different from the actual state of the IoT device registration table TT shown in FIG. That is, the IoT device registration table TT shown in FIG. 24 records the correspondence between the device identification information Q121 (manufacturer name, product model number, product number) and access method information (communication standard, unique address). On the other hand, the IoT device registration table TT ′ stored in the internal terminal intermediary unit 610 in FIG. 29 includes individual communication units 611 to 615 corresponding to the device identification information Q121 (manufacturer name, product model number, product number). Correspondence relationship is recorded. In other words, what is obtained by changing the “access method information” field in the IoT device registration table TT shown in FIG. 24 to the “corresponding individual communication unit” field is the IoT device registration table TT ′.

  However, the IoT device registration table TT shown in FIG. 24 and the IoT device registration table TT ′ stored in the internal terminal mediation unit 610 in FIG. 29 perform substantially the same function. That is, the former is a table that directly associates the device specifying information Q121 of the IoT device with the access method information indicating the access method to the IoT device, whereas the latter is an indirect table. It is a table associated with. As described above, in the present invention, the IoT device registration tables TT and TT ′ stored in the gateway device GW include the device identification information Q121 about the individual IoT devices 701 to 705 connected to the downstream side, and the IoT device. Any table that directly or indirectly associates access method information indicating the access method may be used.

  For example, in the case of the IoT device registration table TT ′, for the device identification information Q121 of the IoT device 702 (air conditioner), the corresponding individual communication unit is the individual communication unit 612 instead of directly recording the access method information. Is recorded. However, the individual communication unit 612 is a component that exclusively performs mutual communication with the IoT device 702 (air conditioner), and performs communication to the unique address “AD702” of the IoT device 702 (air conditioner) on the assumption of the communication standard WiFi. It has a function. Therefore, the information indicating “individual communication unit 612” recorded in the IoT device registration table TT ′ is information that indirectly associates the access method information indicating the communication standard WiFi and the unique address AD702.

  Therefore, when the internal terminal device 600A receives the communication data Q10 or the encrypted communication data Q10C from the network N, the internal terminal intermediary unit 610 refers to the IoT device registration table TT ′ to appropriately receive the received information. Processing to distribute to the individual communication units 611 to 615 can be performed.

  Specifically, the intermediary unit for internal terminal 610, from the communication data Q10 or the encrypted communication data Q10C received by the internal terminal device 600A, the device identification information Q121, the IoT device-addressed data Q122 or the IoT device-addressed encrypted data Q122C, , And by referring to the IoT device registration table TT ′, the individual communication units 611 to 615 corresponding to the extracted device identification information Q121 are selected, and the selected individual communication units 611 to 615 are extracted. The IoT device-addressed data Q122 or the extracted IoT device-addressed encrypted data Q122C is decrypted to give the IoT device-addressed data Q122.

  When the individual communication units 611 to 615 receive the IoT device-addressed data Q122 from the internal terminal intermediary unit 610, the individual communication units 611 to 615 use the predetermined communication standard for the IoT device-addressed data Q122 to the corresponding IoT devices 701 to 705. Send by communication.

  On the other hand, when transmission is performed from the IoT devices 701 to 705 to the external terminal devices 600B to 600D, a procedure reverse to the above is executed. For example, when transmitting terminal device-addressed data Q222 from the IoT device 702 (air conditioner) to the external terminal device 600B (smartphone), first, the IoT device 702 (air conditioner) sends the individual communication unit 612 to the terminal device. Data Q222 is transmitted. Thereafter, the terminal device-addressed data Q222 is delivered from the individual communication unit 612 to the internal terminal mediation unit 610, where communication data Q20 as shown in FIG. 27 or encrypted communication data Q20C as shown in FIG. 28 is created. The The procedure for transmitting the communication data Q20 or the encrypted communication data Q20C created in this way from the internal terminal device 600A to the external terminal device 600B is as already described in §9.

<10.2 Modification of Gateway Device Configuration>
Next, a modified example of the configuration example of the gateway device GW shown in FIG. 29 will be described with reference to FIG. The gateway device GW ′ according to the modification shown in FIG. 30 is obtained by adding a normal router unit 620 to the gateway device GW shown in FIG. The normal router unit 620 is a general router device having a routing function for connecting the IoT devices 701 to 705 connected on the downstream side to the network N connected on the upstream side.

  Therefore, in the case of this modification, each of the IoT devices 701 to 705 is connected to the external terminal device via the network N (Internet) through the following two connection paths.

  First, the first connection path is a connection path that has been mediated by the connection mediating apparatus 500 as described above, and is registered in the address table T in the connection mediating apparatus 500 via the internal terminal apparatus 600A. It is a connection path that allows connection only to the external terminal device that is connected. In the case of the example shown in FIG. 22, the IoT devices 701 to 705 can connect only to the external terminal devices 600 </ b> B to 600 </ b> D in the connection using the first connection path.

  On the other hand, the second connection path is a connection path via the normal router unit 620. The normal router unit 620 plays a role of connecting each IoT device 701 to 705 to the Internet N using a general router function, like the router R shown in FIG. Therefore, each IoT device 701 to 705 is assigned a private IP address within the network constructed by the normal router unit 620. The normal router unit 620 converts the private IP address into a global IP address and port number format by the NAPT function, and connects to the Internet N.

  Since the communication using the first connection path described above requires the mediation by the connection mediating apparatus 500, the communication is performed only between terminal devices registered in the address table T in advance. In other words, the internal terminal device 600A that governs communication using the first connection path executes only communication that has been mediated by the connection mediating device 500. Therefore, an unauthorized terminal device 19 as shown in FIG. 21 can be prevented from accessing each IoT device using this first connection path, and sufficient security can be ensured. However, since the terminal devices that can communicate with each IoT device are limited to the terminal devices registered in the address table T, the degree of freedom of communication is greatly limited.

  On the other hand, in the communication using the second connection path described above, the terminal device to be a communication partner is not particularly limited, and communication with any terminal device not registered in the address table T is possible. For this reason, although the degree of freedom of communication is greatly improved, since the unauthorized terminal device 19 is also included in the communication partner, security must be reduced. Therefore, in practice, it is preferable to impose restrictions as described below for communications normally performed by the router unit 620.

Here, communication that can be performed by the normal router unit 620 is classified into the following three types. In the following description, “upstream communication” refers to communication in which information flows from the downstream side to the upstream side of the normal router unit 620, and “downstream communication” refers to communication from the upstream side of the normal router unit 620. This refers to communication in which information flows toward the downstream side.
(a) Upstream communication from the IoT devices 701 to 705 toward the network N,
(b) Out of down communication from the network N to the IoT devices 701 to 705, down communication returned as a response to the up communication,
(c) Downstream communication other than the above (b) among the downstream communications from the network N to the IoT devices 701 to 705.

  The communication (a) corresponds to a case where some information is transmitted from the IoT device side to the network N. For example, the IoT device 701 (monitoring camera) takes a photographed image with respect to a predetermined terminal device via the network N. Is transmitted, the upstream communication referred to in this communication (a) is executed. In addition, for example, when an IoT device transmits an HTTP request to a terminal device functioning as a Web server, this corresponds to the upstream communication referred to in this communication (a). Specifically, when the IoT device 703 (refrigerator) requests a menu for various ingredients from the Web server, or the IoT device 704 (video deck) requests a TV program list from the Web server. In addition, such an HTTP request is transmitted.

  When performing such upstream communication, if the communication destination terminal device is an external terminal device registered in the address table T, communication is performed via the first connection path via the internal terminal device 600A. However, if this is not the case, communication via the second connection path via the normal router unit 620 must be performed.

  On the other hand, the communications (b) and (c) both correspond to the case where some information transmitted via the network N is delivered to the IoT device side. However, communication (b) indicates the case where the transmitted information is information returned as a response to the upstream communication of communication (a), and communication (c) indicates the case where it is other information. Show. For example, as described above, when an IoT device transmits an HTTP request to a predetermined Web server (the upstream communication referred to as communication (a) has been performed), the Web server receives the HTTP request. An HTTP response corresponding to the request is returned. Since the HTTP response returned in this way is information returned as a response to the upstream communication of communication (a), it corresponds to the downstream communication referred to as communication (b).

  Further, when the external terminal device 600D (update server) shown in FIG. 22 performs push-type distribution of the update data to the normal router unit 620, the update data is sent from the communication (a) transmitted from the IoT device side. Since it is not information returned as a response to communication, it is downstream communication as referred to as communication (c). In response to this, the external terminal device 600D (update server) sends a pull-type distribution of the updater to the normal router unit 620 as a response to the update request (upstream communication of communication (a)) transmitted from the IoT device side. If so, the updater will be the downstream communication referred to in communication (b).

  As described above, when the communications that can be normally performed by the router unit 620 are classified into the three forms (a), (b), and (c), the communications of (a) and (b) are executed, It is preferable to set to reject the communication of c) in order to improve the security of the IoT device. First, since the communication (a) is communication that goes out from the IoT device to the network N, it does not threaten the security of the IoT device, so there is no need to restrict it, and it may be always executed. .

  On the other hand, since the communications (b) and (c) are communications entering the IoT device from the network N, if this is executed and the communication data is accepted, the IoT device may be hacked. There is sex. However, since communication (b) is communication that was originally returned as a response to communication (a) performed from the IoT device, it is less likely to be a security threat compared to communication (c). On the other hand, since the communication (c) is unilaterally performed from an external terminal device, the possibility of being a security threat increases. From such a point of view, it is preferable that the communication (a) and the communication (b) be executed and the communication (c) be rejected in practice.

  Then, as shown in the above example, the IoT device transmits an HTTP request to the predetermined Web server (communication (a)), and an HTTP response corresponding to the HTTP request is returned from the Web server. If so, the HTTP response corresponds to communication (b) and is accepted and delivered to the IoT device. On the other hand, when there is any information transmission from the unauthorized terminal device 19, the information transmission is rejected because it corresponds to communication (c).

  Of course, if the above operation is performed, update data by push distribution is transmitted from the external terminal device 600D (update server) shown in FIG. 22 to the normal router unit 620 using the second connection path. If this happens, it will be rejected because it falls under communication (c). However, as described above, the external terminal device 600D only needs to transmit the update data by push-type distribution to the internal terminal device 600A using the first connection path, so that there is no problem.

  In order to cause the normal router unit 620 to execute communication (a) and communication (b) and to reject communication (c), communication from the downstream side to the upstream side (communication (a)) is performed. In addition to executing this unconditionally, the combination of the address of the terminal device serving as the communication destination and the port number corresponding to the IoT device serving as the transmission source is stored for a certain period of time. For the communication going to (communication (b), (c)), the combination of the address of the terminal device serving as the communication source and the port number corresponding to the IoT device serving as the destination matched one of the stored combinations If this is the case (communication (b)), this is executed, and if they do not match (communication (c)), this may be rejected.

11: Terminal device (smartphone)
12: Terminal device (PC)
13: Terminal device (update server)
19: Unauthorized terminal device 100: Connection mediating device 110: Address table storage unit 120: Address table update unit 130: Destination address reply unit 200, 200A to 200K: Terminal device 201H, 201K: VPN communication unit 210, 210A, 210B : Connection mediation request unit 220, 220A, 220B: communication request reception unit 230, 230A, 230B: communication destination session establishment unit 240, 240A, 240B: communication start request unit 250, 250A, 250B: self address notification unit 260, 260A, 260B: Source session establishment unit 300: Connection mediation device 310: Address table storage unit 320: Address table update unit 330: Source address transmission units 400, 400A to 400D: Terminal devices 410, 410A, 410B: Connection mediation request unit 420 , 42 A, 420B: Communication request receiving unit 430, 430A, 430B: Communication source session establishment unit 440, 440A, 440B: Communication start request unit 450, 450A, 450B: Self address notification unit 460, 460A, 460B: Communication destination session establishment unit 500: Connection mediating device 600A: Internal terminal device (terminal device incorporated in gateway device GW)
600B: External terminal device (smartphone)
600C: External terminal device (PC)
600D: External terminal device (update server)
610: Internal terminal intermediary unit 611-615: Individual communication unit 620: Normal router unit 701-705: IoT devices AD1-AD4, AD11-AD14: Location address AD701-AD705: Unique address ADx, ADy, ADz: Global IP address APP1, APP2: Application program C: Automotive C1-C4: In-vehicle IoT device GW, GW ': Gateway device H: Home H1-H7: IoT device assuming personal use N: Network (Internet)
P1 to P21: Port number Q10: Communication data (IP packet)
Q10C: Encrypted communication data (IP packet)
Q11: IP header part Q12, Q12C: IP data part Q20: Communication data (IP packet)
Q20C: Encrypted communication data (IP packet)
Q21: IP header portion Q22, Q22C: IP data portion Q111: transmission source address Q112: transmission destination address Q121: device identification information Q122: IoT device transmission data Q122C: IoT device transmission data Q211: transmission source address Q212: transmission destination address Q220: Terminal device identification information Q221: Device identification information Q222: IoT device-addressed data Q222C: IoT device-addressed encrypted data R, R1, R2: Routers S1 to S7, S11 to S17: Steps T, T1 to T3, T41 of the flowchart , T42, T51, T52: Address table TT, TT ': IoT device table U: Unique data stored in the IoT device

Claims (17)

A plurality of terminal devices (200, 200A-200K, 600A-600D) that can be connected to each other via a network (N), and a connection mediating device (100, 500) that mediates connection between the plurality of terminal devices; A network communication system comprising a gateway device (GW, GW ′) including one (600A) of the terminal devices (200, 200A-200K, 600A-600D),
Each of the terminal devices (200, 200A-200K, 600A-600D) is assigned a terminal ID for identifying each terminal device, and the connection mediating device (100, 500) Using the terminal ID, execute a process that mediates the connection between the terminal device (200A) as the communication source and the terminal device (200B) as the communication destination,
Each of the plurality of terminal devices (200, 200A-200K, 600A-600D)
A self-address notifying unit (250) for notifying the connection mediating device (100, 500) of a location address indicating a location on its own network;
A communication request accepting unit (220A) that accepts a communication request (S1) to another terminal device (200B) as a communication destination with the self (200A) as a communication source;
When the communication request (S1) is received by the communication request receiving unit (220A), the terminal ID (200B) of another terminal device (200B) of the communication destination is sent to the connection mediating device (100, 500). A connection mediation request unit (210A) for transmitting a connection mediation request (S2) including communication destination specifying information for specifying (0020)
In response to the connection mediation request (S2), the connection mediation device (100, 500) returns a communication destination address (AD2) indicating the location of another terminal device (200B) of the communication destination on the network. A communication start request unit (240A) that accesses the communication destination address (AD2) and makes a communication start request (S5) via the network (N),
In response to the communication start request (S5), when a communication start acceptance confirmation (S6) is returned from another terminal device (200B) of the communication destination, the communication with the other terminal device (200B) of the communication destination A communication source session establishment unit (260A) for establishing a communication session between them and starting communication (S7);
When a communication start request (S5) with itself as the communication destination is made from another terminal device (200A) of the communication source, a communication start acceptance confirmation (S6) is made to the other terminal device (200A) of the communication source. A communication destination session establishing unit (230B) for transmitting and establishing a communication session with another terminal device (200A) of the communication source and starting communication (S7);
Have
The connection mediating device (100, 500)
For each of the terminal devices (200, 200A-200K, 600A-600D), an address table storage unit (110) that stores an address table (T, T41 to T52) that associates the terminal ID with the location address; ,
An address table updating unit (T, T41 to T52) for updating the contents of the address table (T, T41 to T52) based on the notification from the self address notification unit (250) of the terminal device (200, 200A-200K, 600A-600D) 120),
When the connection mediation request (S2) is transmitted from the connection mediation request unit (210A) of the terminal device (200A), the connection mediation is referred to by referring to the address table (T, T41 to T52). A communication destination address reply unit (130) for returning a location address (AD2) associated with the terminal ID (0020) specified by the communication destination specifying information included in the request (S2) as a communication destination address;
Have
The gateway device (GW, GW ′) serves to connect one or more IoT devices (701-705) connected to the downstream side to the network (N) connected to the upstream side,
External terminal devices (600B-600D) not included in the gateway device (GW, GW ′) communicate with a specific IoT device connected to the downstream side of the gateway device (GW, GW ′). When
The connection mediation request unit (210) of the external terminal device (600B-600D) includes communication destination specifying information for specifying the internal terminal device (600A) included in the gateway device (GW, GW ′). Sending a connection mediation request (S2) to the connection mediation device (500);
The communication start request unit (240) of the external terminal device (600B-600D) accesses the communication destination address (AD11) returned in response to the connection mediation request (S2) and sends a communication start request (S5). Done
When the communication source session establishment unit (260) of the external terminal device (600B-600D) performs communication (S7) to the communication destination session establishment unit (230) of the internal terminal device (600A), Communication data (Q10) including IoT device-addressed data (Q122) to be transmitted to the specific IoT device and device specifying information (Q121) specifying the specific IoT device for the terminal device (600A) Send
When the gateway device (GW, GW ′) receives the communication data (Q10), the gateway device (GW, GW ′) extracts the device identification information (Q121) and the IoT device address data (Q122) from the communication data (Q10), A network communication system, wherein the IoT device-addressed data (Q122) is distributed to the IoT devices (701-705) specified by the device specifying information (Q121). The network communication system according to claim 1, wherein
When a specific IoT device communicates with a specific external terminal device (600B),
The specific IoT device, with respect to the communication request receiving unit (220) of the internal terminal device (600A), terminal device specifying information (Q220) for specifying the specific external terminal device (600B), and the specifying Device identification information (Q221) for identifying the IoT device and terminal device data (Q222) to be transmitted to the specific external terminal device (600B) as a communication request (S1),
The connection mediation request unit (210) of the internal terminal device (600A) connects the connection mediation request (S2) including communication destination specifying information whose communication destination is the terminal device specified by the terminal device specifying information (Q220). To the mediation device (500),
The communication start request unit (240) of the internal terminal device (600A) accesses the communication destination address (AD12) returned in response to the connection mediation request (S2) and makes a communication start request (S5).
When performing communication (S7) between the communication source session establishment unit (260) of the internal terminal device (600A) and the communication destination session establishment unit (230) of the specific external terminal device (600B), Communication data (Q20) including the device identification information (Q221) and the data addressed to the terminal device (Q222) is transmitted from the internal terminal device (600A) to the specific external terminal device (600B). A network communication system. A plurality of terminal devices (400, 400A-400D, 600A-600D) that can be connected to each other via a network (N), and a connection mediating device (300, 500) that mediates connections between the plurality of terminal devices; A network communication system comprising a gateway device (GW, GW ′) including one of the terminal devices (400, 400A-400D, 600A-600D) (600A),
Each of the terminal devices (400, 400A-400D, 600A-600D) is assigned a terminal ID for identifying each terminal device, and the connection mediating device (300, 500) Using the terminal ID, execute a process that mediates the connection between the terminal device (400B) serving as a communication source and the terminal device (400A) serving as a communication destination,
Each of the plurality of terminal devices (400, 400A-400D, 600A-600D)
A self-address notifying unit (450) for notifying the connection mediating device (300, 500) of a location address indicating a location on its own network;
A communication request accepting unit (420B) that accepts a communication request (S11) to another terminal device (400A) that is a communication destination with the self (400B) as a communication source;
When the communication request (S11) is received by the communication request receiving unit (420B), the terminal ID (400A) of another terminal device (400A) of the communication destination is sent to the connection mediating device (300, 500). A connection mediation request unit (410B) for transmitting a connection mediation request (S12) including communication destination specifying information for specifying (0010);
When a communication source address (AD2) indicating the location of another terminal device (400B) that is a communication source is transmitted from the connection mediating device (300, 500) via the network (N). A communication start request unit (440A) that accesses the communication source address (AD2) and makes a communication start request (S15);
When a communication start acceptance confirmation (S16) is returned from another terminal device (400B) of the communication source in response to the communication start request (S15), the communication with the other terminal device (400B) of the communication source is performed. A communication destination session establishment unit (460A) that establishes a communication session between them and starts communication (S17);
When a communication start request (S15) is issued from the other terminal device (400A) as the communication destination with the communication source (400B) as the communication source, confirmation of acceptance of communication start is made to the other terminal device (400A) as the communication destination. A communication source session establishment unit (430B) that transmits (S16), establishes a communication session with another terminal device (400A) of the communication destination and starts communication (S17);
Have
The connection mediating device (300, 500)
For each of the terminal devices (400A-400D, 600A-600D), an address table storage unit (310) that stores an address table (T, T41 to T52) that associates the terminal ID with the location address;
Address table updating unit (320) for updating the contents of the address tables (T, T41 to T52) based on the notification from the self-address notification unit (450) of the terminal device (400A-400D, 600A-600D) When,
When the connection mediation request (S12) is transmitted from the connection mediation request unit (410B) of the terminal device (400B), the connection mediation is referred to by referring to the address table (T, T41 to T52). For the location address (AD1) associated with the terminal ID (0010) specified by the communication destination specifying information included in the request (S12), the source of the communication source that transmitted the connection mediation request (S12) A source address transmission unit (330) that transmits a location address (AD2) associated with the terminal ID (0020) of the terminal device (400B) as a source address;
Have
The gateway device (GW, GW ′) serves to connect one or more IoT devices (701-705) connected to the downstream side to the network (N) connected to the upstream side,
External terminal devices (600B-600D) not included in the gateway device (GW, GW ′) communicate with a specific IoT device connected to the downstream side of the gateway device (GW, GW ′). When
The connection mediation request unit (410) of the external terminal device (600B-600D) includes communication destination specifying information for specifying the internal terminal device (600A) included in the gateway device (GW, GW ′). Sending a connection mediation request (S12) to the connection mediation device (500);
The communication start request unit (440) of the internal terminal device (600A) accesses the communication source address (AD12) transmitted in response to the connection mediation request (S12) and makes a communication start request (S15).
When the communication source session establishment unit (430) of the external terminal device (600B-600D) performs communication (S17) to the communication destination session establishment unit (460) of the internal terminal device (600A), the internal session Communication data (Q10) including IoT device-addressed data (Q122) to be transmitted to the specific IoT device and device specifying information (Q121) specifying the specific IoT device for the terminal device (600A) Send
When the gateway device (GW, GW ′) receives the communication data (Q10), the gateway device (GW, GW ′) extracts the device identification information (Q121) and the IoT device address data (Q122) from the communication data (Q10), A network communication system, wherein the IoT device-addressed data (Q122) is distributed to the IoT devices (701-705) specified by the device specifying information (Q121). The network communication system according to claim 3,
When a specific IoT device communicates with a specific external terminal device (600B),
The specific IoT device, with respect to the communication request receiving unit (420) of the internal terminal device (600A), terminal device specifying information (Q220) for specifying the specific external terminal device (600B), and the specifying Device identification information (Q221) for identifying the IoT device and terminal device data (Q222) to be transmitted to the specific external terminal device (600B) as a communication request (S11),
The connection mediation request unit (410) of the internal terminal device (600A) connects the connection mediation request (S12) including communication destination specifying information whose communication destination is the terminal device specified by the terminal device specifying information (Q220). To the mediation device (500),
The communication start request unit (440) of the specific external terminal device (600B) accesses the communication source address (AD11) transmitted in response to the connection mediation request (S12) and sends a communication start request (S15). Done
When performing communication (S17) between the communication source session establishment unit (430) of the internal terminal device (600A) and the communication destination session establishment unit (460) of the specific external terminal device (600B), Communication data (Q20) including the device identification information (Q221) and the data addressed to the terminal device (Q222) is transmitted from the internal terminal device (600A) to the specific external terminal device (600B). A network communication system. In the network communication system according to any one of claims 1 to 4,
The gateway device (GW, GW ′) obtains the IoT device address data (Q122) based on the device identification information (Q121) and the IoT device address data (Q122) included in the received communication data (Q10). A network communication system characterized by delivering to an IoT device (701-705) specified by the device specifying information (Q121). The network communication system according to claim 5, wherein
In the gateway device (GW, GW ′), device identification information (Q121) about each IoT device (701-705) connected downstream, access method information indicating an access method to the IoT device, , IoT device registration tables (TT, TT ′) that directly or indirectly correspond to each other are stored.
When the gateway device (GW, GW ′) receives the communication data (Q10), the gateway device (GW, GW ′) refers to the IoT device registration table (TT, TT ′) to identify the device extracted from the received communication data (Q10). The access method indicated by the access method information corresponding to the information (Q121) is used to access the destination IoT device (701-705), and the IoT device-addressed data (Q122) extracted from the received communication data (Q10) A network communication system characterized by delivering to a destination IoT device (701-705). The network communication system according to claim 6, wherein
The device identification information (Q121) stored in the IoT device registration table (TT) includes the manufacturer name, product model number, and product number of the IoT device,
The access method information stored in the IoT device registration table (TT) includes a communication standard for performing communication with the IoT device and a unique address for performing access according to the communication standard. Communications system. In the network communication system according to any one of claims 1 to 7,
When the communication source session establishment unit (260, 430) of the external terminal device (600B-600D) performs communication (S7, S17) to the communication destination session establishment unit (230, 460) of the internal terminal device (600A) In addition,
For the data addressed to the IoT device (Q122), the unique data (U) stored in the specific IoT device (701-705) as the destination or derived data uniquely obtained from the data (U) Encrypted data (Q122C) addressed to the IoT device is created by performing an encryption process used as an encryption key, and encrypted communication data (Q122C) and the encrypted communication data (Q121) including the device identification information (Q121) are included. Q10C)
When the gateway device (GW, GW ′) receives the encrypted communication data (Q10C), the gateway device (GW, GW ′) uses the device-specific information (Q121) and the IoT device-addressed encrypted data (Q122C) from the encrypted communication data (Q10C). ) And the unique data (U) stored in the IoT device (701-705) identified by the extracted device identification information (Q121) or derived data uniquely obtained from the data (U) The IoT device-addressed data (Q122) is restored by performing a decryption process using as a decryption key, and the restored IoT device-addressed data (Q122) is specified by the extracted device specifying information (Q121). A network communication system, characterized by being distributed to devices (701-705). In the network communication system according to any one of claims 1 to 8,
When the communication source session establishment unit (260, 430) of the external terminal device (600B-600D) performs communication (S7) to the communication destination session establishment unit (230, 460) of the internal terminal device (600A),
An IP header portion including the IP address of the external terminal device (600B-600D) as a transmission source address (Q111) and the IP address of the internal terminal device (600A) as a transmission destination address (Q112); (Q122) or by creating an IP packet (Q10, Q10C) having an IP data part (Q12, Q12C) including encrypted data addressed to the IoT device (Q122C) and device specifying information (Q121), the IoT device The destination data (Q122) or the encrypted data destined for the IoT device (Q122C) is encapsulated in the IP packet (Q10, Q10C), and the IP packet is transmitted to the communication data (Q10) or the encrypted communication data (Q10C). Network communication system characterized by Temu. The network communication system according to claim 9,
The internal terminal device (600A) sets a specific port as a valid port, and changes the current valid port to the connection mediating device (500) at a predetermined cycle or when the setting of the valid port is changed. A process of receiving only IP packets for which the port number corresponding to the valid port is specified among IP packets transmitted through the network (N) and rejecting other IP packets. Done
A network communication system, wherein the connection mediating apparatus (500) performs mediation processing using an address including a port number of the valid port as a communication destination address. The network communication system according to claim 10,
A network communication system, wherein the internal terminal device (600A) always sets only one port as an effective port. The network communication system according to claim 2 or 4,
When the communication source session establishment unit (260, 430) of the internal terminal device (600A) performs communication (S7, S17) to the communication destination session establishment unit (230, 460) of the external terminal device (600B-600D) In addition, the gateway device (GW, GW ′), for the data addressed to the terminal device (Q222), the unique data (U) stored in the specific IoT device (701-705) serving as the transmission source or the data Encrypted data (Q222C) addressed to the terminal device is created by performing encryption processing using derived data uniquely obtained from the data (U) as an encryption key, and the encrypted data addressed to the terminal device (Q222C) and the device specifying information Send encrypted communication data (Q20C) including (Q221),
When the external terminal device (600B-600D) receives the encrypted communication data (Q20C), the external terminal device (600B-600D) responds to the encrypted data (Q222) addressed to the terminal device included in the encrypted communication data (Q20C). The terminal data (Q222) is restored by performing a decryption process using the unique data (U) or derived data uniquely obtained from the data (U) as a decryption key. Network communication system. The network communication system according to any one of claims 2, 4 and 12,
When the communication source session establishment unit (260, 430) of the internal terminal device (600A) performs communication (S7, S17) to the communication destination session establishment unit (230, 460) of the external terminal device (600B-600D) In addition,
An IP header portion (Q21) including the IP address of the internal terminal device (600A) as a transmission source address (Q211) and the IP address of the external terminal device (600B-600D) as a transmission destination address (Q212); By creating an IP packet (Q20, Q20C) having an IP data part (Q22, Q22C) including device addressed data (Q222) or terminal device addressed encrypted data (Q222C) and device specifying information (Q221), The terminal device-addressed data (Q222) or the terminal device-addressed encrypted data (Q222C) is encapsulated in the IP packet (Q20, Q20C), and the IP packet is transmitted as communication data (Q20) or encrypted communication data. (Q20C) is transmitted as a network communication Stem. The network communication system according to any one of claims 1 to 13,
The gateway device (GW, GW ′) is connected to the internal terminal device (600A), the internal terminal intermediary unit (610), and N (N is a natural number) IoT devices (701 to 705) connected downstream. N individual communication units (611-615) corresponding to one-to-one,
The individual communication unit (611-615) has a function of communicating with each corresponding IoT device (701-705) based on a predetermined communication standard,
The internal terminal intermediary unit (610) is associated with device identification information (Q121) on each IoT device (701-705) and an individual communication unit (611-615) corresponding to the IoT device. IoT device registration table (TT ′) is stored,
The intermediary unit for internal terminal (610), from the communication data (Q10) or the encrypted communication data (Q10C) received by the internal terminal device (600A), device identification information (Q121) and IoT device address data (Q122). ) Or IoT device-addressed encryption data (Q122C), and by referring to the IoT device registration table (TT ′), the individual communication unit (611-615) corresponding to the extracted device identification information (Q121) IoT device data (Q122C) obtained by decrypting the extracted IoT device-addressed data (Q122) or the extracted IoT device-addressed encrypted data (Q122C) with respect to the selected individual communication unit (611-615). Q122) is performed, and the network communication system characterized by the above-mentioned. The network communication system according to claim 14, wherein
The gateway device (GW) further includes a normal router unit (620).
The normal router unit (620) has a routing function for connecting the IoT device (701-705) connected to the downstream side to the network (N) connected to the upstream side,
The internal terminal device (600A) executes only the communication (S7, S17) mediated by the connection mediating device (100, 500),
The normal router unit (620)
(a) Upstream communication from the IoT device (701-705) to the network (N),
(b) Out of downstream communications from the network (N) to the IoT device (701-705), downstream communications returned as a response to the upstream communications;
(c) Downstream communication other than the above (b) among downstream communications from the network (N) to the IoT device (701-705),
A network communication system characterized in that communication of (a) and (b) is executed and communication of (c) is rejected among the three forms of communication.   The gateway apparatus (GW, GW ') in the network communication system according to any one of claims 1 to 15.   A program causing a computer to function as the gateway device (GW, GW ') in the network communication system according to any one of claims 1 to 15.

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