Communications processing device and communications method

Abstract

To realize the communication between communication devices belonging to networks whose address systems are different.SOLUTION: A communication processing device includes a first communication unit for receiving a message of a first communication protocol from a first communication device in a first network of a first address system, a communication protocol processor for including address information indicating an address of a second communication device and a message of the first communication protocol into a payload when a destination address of the message matches a first address of the first communication unit, and generating a message of a second communication protocol which requests to transfer the message of the first communication protocol to the second communication device in a second network of a second address system, and a second communication unit for transmitting the message of the second communication protocol to a gateway device that can communicate with the second communication device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a communication processing device and a communication method. [Background technology]

[0002] Industrial controllers are used to automatically control industrial processes, machines, manufacturing equipment, etc. in factories. Terminals equipped with software for controlling the industrial controller, such as setting and issuing operational instructions to the industrial controller, are located on the same local network as the industrial controller. Therefore, in order to control the industrial controller, workers must travel to the location of the terminal, which is inconvenient.

[0003] Recently, there has been a demand for increased convenience by placing the software on a cloud server and enabling remote control of industrial controllers from any location via the server. However, when the software is placed on a cloud server, the cloud is a different network from the industrial controller, and the address systems and communication protocols are different, so the two cannot communicate with each other as is. To enable communication between the two, new functions must be added to both the server software and the industrial controller. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-112577 Summary of the Invention [Problem to be solved by the invention]

[0005] The embodiments of the present invention provide a communications processing device and a communications method that realize communications between communications devices that belong to networks with different address systems. [Means for solving the problem]

[0006] A communication processing device according to an embodiment of the present invention comprises: a first communication unit that receives a message of a first communication protocol from a first communication device in a first network of a first address system; an address identification unit that, when a destination address of the message of the first communication protocol matches a first address in the first address system assigned to the first communication unit, identifies an address of the second communication device corresponding to the first address based on correspondence data that associates the first address with an address of a second communication device in a second network of a second address system; a communication protocol processing unit that generates a message of a second communication protocol that includes address information indicating the address of the second communication device and a message of the first communication protocol in its payload and requests that the message of the first communication protocol be forwarded to the second communication device; and a second communication unit that transmits the message of the second communication protocol to a gateway device that can communicate with the second communication device in the second network. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram of an example of a communication system according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing an example of a conversion table. [Figure 3] FIG. 3 is a diagram showing an example of a sequence according to the first embodiment. [Figure 4] FIG. 10 is a diagram showing another example of the sequence according to the first embodiment. [Figure 5] FIG. 10 is a block diagram of a communication system according to a second embodiment. [Figure 6] FIG. 10 is a diagram showing an example of a sequence according to the second embodiment. [Figure 7] FIG. 10 is a diagram showing another example of a sequence according to the second embodiment. [Figure 8] FIG. 10 is a block diagram of a communication system according to a first modification. [Figure 9] FIG. 10 is a diagram showing an example of a system configuration file. [Figure 10]FIG. 11 is a block diagram of an example of a communication system according to a third modification. [Figure 11] FIG. 11 is a block diagram of another example of a communication system according to the third modification. [Figure 12] FIG. 13 is a block diagram of an example of a communication system according to a fourth modification. [Figure 13] FIG. 13 is a block diagram of an example of a communication system according to a fifth modification. [Figure 14] FIG. 20 is a block diagram of an example of a communication system according to a sixth modification. [Figure 15] FIG. 20 is a block diagram of an example of a communication system according to a seventh modification. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] (First embodiment) 1 is a block diagram of a communication system 1 according to the first embodiment. In the following, an overview of the communication system 1 will first be described with reference to FIG.

[0010] 1, a cloud network N1, which is a first network on the cloud side, and a local network N2, which is a second network located in a facility such as a factory, are connected via a wide area network N3 such as the Internet. The cloud network N1 is a network configured in the cloud.

[0011] A communication source device 101 is connected to a cloud network N1 as a server equipped with software for controlling operation settings or operation instructions for an industrial controller (communication destination device). The communication source device 101 is a first communication device arranged in the cloud network N1. Communication destination devices 201 and 202, which are industrial controllers for automatically controlling industrial processes, machines, manufacturing equipment, etc. in a factory, are connected to a local network N2. The communication destination devices 201 and 202 are second communication devices arranged in the local network N2.

[0012] In order to control the communication destination device 201 or 202, the communication source device 101 transmits a message of a first communication protocol (hereinafter referred to as a control message of the first communication protocol) including control data for the communication destination device 201 or 202. Examples of control include operation settings or operation instructions for the communication destination devices 201 and 202. Examples of the first communication protocol include FTP, SOAP, XML, a vendor protocol, or a proprietary protocol. Examples of the first communication protocol are protocols in a layer higher than a transport layer communication protocol (e.g., UDP / IP or TCP / IP). In order to control the communication destination device 201 or 202 by transmitting a control message of the first communication protocol, it is necessary to deliver the control message of the first communication protocol to the communication destination device 201 or 202.

[0013] The cloud network N1 uses IP addresses in a first address system, while the local network N2 uses IP addresses in a second address system that is independent of the first address system. Both the cloud network N1 and the local network N2 use local IP addresses. Normally, devices belonging to local networks with different address systems cannot communicate directly via the wide area network N3.

[0014] In this embodiment, a mechanism is introduced in which a communication processing device 100 provided on the cloud network N1 side and a gateway device 200 provided on the local network N2 side transfer a control message of the first communication protocol. When the communication source device 101 transmits a control message of the first communication protocol to a destination address predetermined according to the communication destination device 201 or 202 to be controlled, the communication processing device 100 and the gateway device 20 transfer this control message to the communication destination device 201 or 202 by the above mechanism. This makes it possible to transmit a control message of the first communication protocol from the communication source device 101 to the communication destination devices 201 and 202. This makes it possible to transfer the control message of the first communication protocol without adding any new functions to the communication source device 101 and the communication destination devices 201 and 202.

[0015] The outline of this embodiment has been described above. The communication system 1 in FIG. 1 will now be described in detail.

[0016] [Overall configuration of cloud network N1] In FIG. 1, a communication processing device 100 is connected to a communication source device 101 in a cloud network N1. The communication processing device 100 is also connected to a gateway device 200 in a wide area network N3. The cloud network N1 is a wired or wireless network. The wired or wireless network may be Ethernet (registered trademark), WiFi (registered trademark), or the like. The cloud network N1 may also be a network provided in a facility such as a data center.

[0017] [Communication source device 101] The communication source device 101 is a communication device such as a server connected to the cloud network N1. The communication source device 101 may be remotely operable from a user terminal 301 via a wide area network N3. The communication source device 101 is equipped with software for controlling (for example, setting operations and instructing operations) the communication destination devices 201 and 202. The communication source device 101 is a device that controls the communication destination devices 201 and 202 or both of them. The communication source device 101 is assigned an IP address based on an address system (first address system) in the cloud network N1.

[0018] The communication source device 101 generates a message (control message) of the first communication protocol including data for controlling the communication destination device 201 or 202, and generates a packet by adding an IP header or the like to the control message. The trigger for generating the control message may be any timing, such as timing specified by a user or timing when a predetermined event occurs (for example, timing when a specific time arrives). The communication source device 101 sets the destination IP address of the generated packet to the IP address of a conversion function unit that performs processing corresponding to the communication destination device (201 or 202) to be controlled, among multiple conversion function units (110 or 120) in the communication processing device. The communication source device 101 outputs the generated packet to the cloud network N1.

[0019] [Communications processing device 100] The communication processing device 100 includes a conversion function unit 110 and a conversion function unit 120. The communication processing device 100 is configured as a computer device including circuits such as a processor or CPU, a storage device such as a memory or hard disk, a communication circuit, etc. This device may be configured as a single computer device, or may be configured as a system consisting of multiple computer devices connected to each other. The functions of the communication processing device 100 may be realized by causing the CPU to execute a program.

[0020] The conversion function unit 110 includes an IP address identification unit 111 (address identification unit), a communication protocol processing unit 112, an internal communication unit 113 (first communication unit), and an external communication unit 114 (second communication unit). The internal communication unit 113 communicates on the cloud network N1 side, and the external communication unit 114 communicates on the wide area network N3 side. The conversion function unit 110 or the internal communication unit 113 is assigned 192.168.1.111 as a local IP address for the cloud network N1. The conversion function unit 110 or the external communication unit 114 is assigned 10.0.0.10 as a global IP address for the wide area network N3.

[0021] The conversion function unit 120 includes an IP address identification unit 121 (address identification unit), a communication protocol processing unit 122, an internal communication unit 123 (first communication unit), and an external communication unit 124 (second communication unit). The internal communication unit 123 communicates on the cloud network N1 side, and the external communication unit 124 communicates on the wide area network N3 side. The conversion function unit 120 or the internal communication unit 123 is assigned 192.168.1.112 as a local IP address for the cloud network N1. The conversion function unit 120 or the external communication unit 124 is assigned 10.0.0.10 as a global IP address for the wide area network N3, the same as the conversion function unit 110. In practice, the same global IP address may be assigned to a communication interface common to the conversion function unit 110 and the conversion function unit 120. Alternatively, the global IP addresses of the conversion function unit 110 and the conversion function unit 120 may be different.

[0022] The communication protocol processing unit 112 of the conversion function unit 110 and the communication protocol processing unit 122 of the function conversion unit 120 have a function for processing a second communication protocol. Examples of the second communication protocol include HTTPS or HTTP. The second communication protocol is a communication protocol different from the first communication protocol and may be higher or lower than the first communication protocol in the hierarchical structure of communication protocols. In this embodiment, it is mainly assumed that the second communication protocol is HTTPS. HTTPS is assumed to be a higher-level protocol than the first communication protocol. The conversion function units 110 and 120 may have a function as an HTTPS server as the second communication protocol.

[0023] When the internal communication unit 113 of the conversion function unit 110 receives a control message of a first communication protocol addressed to the local IP address of the conversion function unit 110 from the communication source device 101, the internal communication unit 113 stores the source IP address of the control message in a memory inside the conversion function unit 110. More specifically, when the internal communication unit 113 receives a packet including a control message of the first communication protocol, the internal communication unit 113 stores the IP address included in the source address field of the packet in a memory inside the conversion function unit 110. Then, the conversion function unit 110 performs a message conversion process (or simply a conversion process) using an IP address identification unit 111 and a communication protocol processing unit 112, which will be described below. The conversion process is to generate a message of the second communication protocol (a transfer request message) that requests the transfer of the control message of the first communication protocol by wrapping data including the control message of the first communication protocol and the like in the second communication protocol.

[0024] The IP address identification unit 111 has correspondence data (conversion table) that associates the local IP address of the conversion function unit 110 with the local IP address of the communication destination device 201.

[0025] FIG. 2A shows an example of a conversion table held by the IP address identification unit 111. If the destination IP address of a packet received from the communication source device 101 matches the local IP address of the conversion function unit 110, the IP address identification unit 111 identifies the corresponding local IP address of the communication destination device 201 from the conversion table.

[0026] The communications protocol processing unit 112 generates a payload including address information indicating the local IP address (192.168.0.10) of the communication destination device 201 identified by the IP address identification unit 111 and the control message of the first communications protocol included in the received packet. The communications protocol processing unit 112 generates a transfer request message of the second communications protocol by adding a header of the second communications protocol to the beginning of the generated payload. Thereafter, the communications protocol processing unit 112 further adds an IP header and the like to the transfer request message of the second communications protocol to create a packet.

[0027] The source IP address of the IP header added to the transfer request message of the second communication protocol is the global IP address (10.0.0.10) of the conversion function unit 110. The destination IP address is the global IP address of the gateway device 200, more specifically, the global IP address (133.113.107.110) of the conversion function unit 210 in the gateway device 200.

[0028] The external communication unit 114 of the conversion function unit 110 outputs the generated packet to the wide area network N3. As a result, the external communication unit 114 transmits a transfer request message in the second communication protocol to the gateway device 200 via the wide area network N3.

[0029] The conversion function unit 120 has the same functions as the conversion function unit 110, except that the communication destination device that is the target of the conversion process is the communication destination device 202. The conversion function unit 120 performs message conversion processing when the internal communication unit 123 receives from the communication source device 101 a packet addressed to the local IP address of the conversion function unit 120, that is, a packet including a control message of the first communication protocol that includes control data for the communication destination device 202. The conversion function unit 120 stores the source IP address of the packet received from the communication source device 101 in an internal memory.

[0030] The IP address identification unit 121 of the conversion function unit 120 has correspondence data (conversion table) that associates the local IP address of the conversion function unit 120 itself with the local IP address of the communication destination device 202 .

[0031] FIG. 2B shows an example of a conversion table of the IP address identification unit 121. If the destination IP address of a packet received from the communication source device 101 matches the local IP address of the conversion function unit 120, the IP address identification unit 121 identifies the corresponding local IP address of the communication destination device 202 from the conversion table.

[0032] The communications protocol processing unit 122 generates a payload that includes address information indicating the local IP address (192.168.0.11) of the communication destination device 202 identified by the IP address identification unit 121 and the control message of the first communications protocol that was included in the received packet. The communications protocol processing unit 122 generates a transfer request message of the second communications protocol by adding a header of the second communications protocol to the beginning of the generated payload. Thereafter, the communications protocol processing unit 122 further adds an IP header and the like to the transfer request message of the second communications protocol to create a packet.

[0033] The source IP address of the IP header is the global IP address (10.0.0.10) of the conversion function unit 120, and the destination IP address is the global IP address (133.113.107.110) of the conversion function unit 220 in the gateway device 200.

[0034] The external communication unit 124 of the conversion function unit 120 outputs the generated packet to the wide area network N3. As a result, the external communication unit 124 transmits a transfer request message in the second communication protocol to the gateway device 200 via the wide area network N3.

[0035] [Gateway device 200] The gateway device 200 is connected to the communication processing device 100 in the wide area network N3. The gateway device 200 is connected to communication destination devices 201 and 202 in the local network N2. The gateway device 200 receives a transfer request message of the second communication protocol transmitted from the communication processing device 100, more specifically, a packet including the transfer request message of the second communication protocol. The gateway device 200 determines a communication destination device to which a control message of the first communication protocol is to be transferred, from address information included in the payload of the transfer request message of the second communication protocol. The gateway device 200 transfers (transmits) the control message of the first communication protocol to the determined communication destination device. The gateway device 200 will be described in further detail below.

[0036] The gateway device 200 has a conversion function unit 210. The conversion function unit 210 includes a communication protocol processing unit 212, an internal communication unit 213, and an external communication unit 214. The internal communication unit 213 communicates on the local network N2 side, and the external communication unit 214 communicates on the wide area network N3 side. The conversion function unit 210 or the external communication unit 214 is assigned a global IP address (133.113.107.110) on the wide area network N3 side. The conversion function unit 210 or the internal communication unit 213 is assigned a local IP address (192.168.0.100) on the local network N2 side. The conversion function unit 210 has a function of processing a second communication protocol. The conversion function unit 210 may have an HTTPS client function as the second communication protocol.

[0037] The communication protocol processing unit 212 has a function of processing the second communication protocol. It receives a transfer request message of the second communication protocol addressed to the global IP address of the gateway device 200, more specifically, a packet including the transfer request message of the second communication protocol. Upon receiving the packet, the communication protocol processing unit 212 processes the header of the transfer request message of the second communication protocol included in the packet to obtain the payload. Then, it reads address information and a control message of the first communication protocol from the obtained payload.

[0038] The communication protocol processing unit 212 generates an IP header etc. with the IP address indicated by the address information (the IP address of the communication destination device 201 or the communication destination device 201) as the destination, and generates a packet by adding the generated IP header etc. to a control message of the first communication protocol. The source address of the IP header is the local IP address (192.168.0.100) of the gateway device 200. The internal communication unit 213 of the conversion function unit 210 outputs the generated packet to the local network N2. As a result, the control message of the first communication protocol is sent to the communication destination device (201 or 202) that has been assigned the IP address indicated by the address information. The output packet is received by the communication destination device (201 or 202).

[0039] The gateway device 200 is configured as a computer device including circuits such as a processor or CPU, storage devices such as memory or hard disks, and communication circuits. This device may be configured as a single computer device, or as a system consisting of multiple interconnected computer devices. The functions of the gateway device 200 may be realized by causing the CPU to execute a program.

[0040] [Communication destination devices 201 and 202] The communication destination devices 201 and 202 are communication devices such as industrial controllers that are connected to the local network N2 and are controlled by the communication source device 101. The communication destination devices 201 and 202 are assigned IP addresses based on the address system (second address system) of the local network N2. The communication destination device 201 is assigned a local IP address of 192.168.0.10. The communication destination device 202 is assigned a local IP address of 192.168.0.11. The local network N2 is a wired or wireless local network. The wired or wireless local network may be Ethernet (registered trademark), WiFi (registered trademark), or the like.

[0041] Destination device 201 receives a control message of the first communication protocol addressed to itself, more specifically, a packet addressed to itself including the control message of the first communication protocol, from gateway device 200. Destination device 201 acquires the control message of the first communication protocol included in the received packet, and operates in accordance with the control data included in the acquired control message. Similarly, destination device 202 receives a control message of the first communication protocol addressed to itself, more specifically, a packet addressed to itself including the control message of the first communication protocol. Destination device 202 acquires the control message of the first communication protocol included in the received packet, and operates in accordance with the control data included in the acquired control message.

[0042] 3 is a diagram showing sequences between devices when a control message of a first communication protocol is transmitted from a communication source device 101 to a communication destination device 202, together with the structure of a packet transmitted in each sequence. Note that the packet structure is shown only schematically to the extent necessary for explaining this embodiment, and may actually include headers of other communication protocols (e.g., a TCP or UDP header, a MAC header, a PHY header, etc.) not shown.

[0043] The communication source device 101 generates a message (control message) of the first communication protocol including control data for the communication destination device 202, and generates a packet P1 by adding an IP header and the like to the control message. The destination IP address of the packet P1 ("DST" in FIG. 3) is the local IP address of the conversion function unit 120 that performs processing corresponding to the communication destination device 202 to be controlled. The source IP address of the packet P1 ("SRC" in FIG. 3) is the local IP address of the communication source device 101. The communication source device 101 outputs the generated packet P1 to the cloud network N1 (S101).

[0044] The conversion function unit 120 of the communication processing device 100 receives a packet P1 from the communication source device 101. Because the destination IP address of the packet P1 matches the IP address of the conversion function unit 120, the IP address identification unit 121 of the conversion function unit 120 acquires the local IP address of the communication destination device 202 corresponding to the destination IP address of the received packet P1 based on the conversion table (see FIG. 2(B)). The communication protocol processing unit 122 generates a payload including address information indicating the acquired local IP address of the communication destination device 202 and a control message of the first communication protocol included in the received packet. The communication protocol processing unit 122 adds an IP header and the like to the payload. The source IP address (SRC in FIG. 3) of the IP header is the global IP address of the conversion function unit 120, and the destination IP address (DST in FIG. 3) is the global IP address of the conversion function unit 210 in the gateway device 200. The communication protocol processing unit 122 also generates a header of the second communication protocol (HTTPS header). By adding a header to the payload, a transfer request message (HTTPS message) of the second communication protocol and packet P2 are generated. The conversion function unit 120 outputs the generated packet P2 to the wide area network N3 (S102). The conversion function unit 120 stores the source IP address of packet P1 received from the communication source device 101 in an internal memory.

[0045] The gateway device 200 receives a packet P2 transmitted from the conversion function unit 120 of the communication processing device 100. The communication protocol processing unit 212 in the conversion function unit 210 of the gateway device 200 acquires address information and a control message of the first communication protocol from the payload of the transfer request message of the second communication protocol included in the received packet P2. The communication protocol processing unit 212 generates an IP header and the like destined for the IP address indicated by the address information (the IP address of the communication destination device 202), and adds the generated IP header and the like to the control message of the first communication protocol to generate a packet P3. The source of the IP header is the local IP address of the gateway device 200. The conversion function unit 210 outputs the generated packet to the local network N2 (S103). The output packet is received by the communication destination device 202.

[0046] The communication destination device 202 receives a packet P3 whose destination IP address is the IP address of the device itself from the gateway device 200. The communication destination device 202 acquires a control message of the first communication protocol included in the received packet P3, and operates in accordance with the control data included in the acquired control message.

[0047] The above explanation has shown a case where a control message of the first communication protocol is transmitted from communication source device 101 to communication destination device 202. Below, an operation will be explained in which communication destination device 202, which has received the control message, transmits a message of the first communication protocol (response message) including response data as a control result for communication source device 101.

[0048] FIG. 4 is a diagram showing a sequence between devices when a response message of the first communication protocol is transmitted from communication destination device 202 to communication source device 101, together with a schematic structure of a packet transmitted in this sequence.

[0049] The communication destination device 202 generates a packet P4 by adding an IP header addressed to the gateway device 200 to the response message of the first communication protocol, and outputs the generated packet P4 to the local network N2 (S111). The source IP address of the packet P4 is the local IP address of the communication destination device 202, and the destination address is the local IP address of the gateway device 200 (conversion function unit 210).

[0050] The communication protocol processing unit 212 in the conversion function unit 210 of the gateway device 200 acquires a source IP address from the IP header of the received packet P4, and also acquires a response message of the first communication protocol from the packet P4. The communication protocol processing unit 212 generates a payload including address information indicating the acquired source IP address (the local IP address of the communication destination device 202) and a response message of the first communication protocol. The communication protocol processing unit 212 generates an IP header and the like with the global IP address of the gateway device 200 as the source IP address and the global IP address of the communication processing device 100 as the destination IP address. The conversion function unit 210 adds the generated IP header and the like to the payload. The communication protocol processing unit 212 also adds a header of the second communication protocol to the payload. As a result, a transfer request message of the second communication protocol and a packet P5 are generated. The transfer request message is a message requesting that the response message be transferred to the communication source device that transmitted the control message. The conversion function unit 210 outputs the generated packet P5 to the wide area network N3 (S112). As a result, a transfer request message in the second communication protocol is transmitted to the communication processing device 100 via the wide area network N3.

[0051] The communication protocol processing unit 122 of the conversion function unit 120 of the communication processing device 100 processes the header of the transfer request message of the second communication protocol included in the received packet P5 and obtains address information and a response message of the first communication protocol from the payload. Since the address information indicates the IP address of the communication destination device 202 corresponding to the conversion function unit 120, the IP address of the communication source device 101 stored in internal memory is read. The conversion function unit 120 generates an IP header and the like with the read IP address as the destination IP address and its own local IP address as the source IP address. The conversion function unit 120 adds the IP header and the like to the response message of the first communication protocol to generate packet P6 and outputs packet P6 to the cloud network N1 (S113). The output packet P6 is received by the communication source device 101. Packet P5 from gateway device 200 is also received by conversion function unit 110, but since the address information does not indicate the IP address of destination device 201 corresponding to conversion function unit 110, conversion function unit 110 discards packet P5.

[0052] Upon receiving packet P6, the communication source device 101 reads the response message of the first communication protocol included in packet P6. The communication source device 101 can determine whether the response message is from communication destination device 201 or 202 based on the source IP address of packet P6. If the source IP address is the IP address of the conversion function unit 120, it can be determined that the response message is from communication destination device 202. If the source IP address is the IP address of the conversion function unit 110, it can be determined that the response message is from communication destination device 201. The communication source device 101 operates based on the response data included in the response message. For example, if the response data indicates that the control was executed correctly, the communication source device 101 performs processing to send control data to be executed next. Alternatively, if the response data indicates that an error was detected in the control, the communication source device 101 may perform processing such as reporting the error to a user.

[0053] 4 has been explained as an example in which a control message in the first communication protocol is transmitted from the communication source device 101 to the communication destination device 202, and a response message in the first communication protocol is transmitted from the communication destination device 202 to the communication source device 101. The same operations as above are performed when a control message in the first communication protocol is transmitted from the communication source device 101 to the communication destination device 201, and a response message in the first communication protocol is transmitted from the communication destination device 201 to the communication source device 101. However, in this case, the conversion function unit 110 is used as the conversion function unit instead of the conversion function unit 120.

[0054] In this embodiment, there are two communication destination devices in the local network N2, but there may be one, or three or more communication destination devices. Since a conversion function unit is provided for each communication destination device, the number of conversion function units may be changed appropriately depending on the number of communication destination devices.

[0055] As described above, according to this embodiment, when the communication source device 101 transmits a control message in the first communication protocol to the conversion function unit (110 or 120), the control message in the first communication protocol is forwarded to the communication destination device (201 or 202) corresponding to the conversion function unit (110 or 120). Also, when the communication destination device (201 or 202) transmits a response message in the first communication protocol to the conversion function unit 210 of the gateway device 200, the response message is forwarded to the communication source device 101. Therefore, communication in the first communication protocol becomes possible between the communication source device and the communication destination device without adding new functions to the existing communication source device and the existing communication destination device.

[0056] Furthermore, according to this embodiment, the IP address information added to the control message of the first communication protocol for transmission in the local network N2 can be a local IP address in the local network N2, so there is no need for the gateway device 200 to identify a local IP address in the cloud network N1. Therefore, the gateway device 200 does not need to know the conversion table. This simplifies the configuration of the gateway device 200.

[0057] (Second embodiment) While the first embodiment described above has one communication source device, the second embodiment deals with a case in which there are two communication source devices and each communication source device uses a different type of first communication protocol. As with the first embodiment, there are two communication destination devices, and both communication destination devices are compatible with two types of first communication protocols. In other words, two types of applications compatible with the two types of first communication protocols are running in each communication destination device, and each application is capable of processing control messages of the corresponding type of first communication protocol. Each communication destination device is also capable of processing control messages of either type of first protocol of the two communication source devices using the corresponding application. This embodiment will be described in detail below. Explanations that are the same as those in the first embodiment will be omitted as appropriate.

[0058] Fig. 5 is a block diagram of a communication system 2 according to the second embodiment. Elements that are the same as or correspond to those in Fig. 1 are given the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0059] A communication source device 101 and a communication source device 102 are connected to a cloud network N1. The IP addresses of the communication source device 101 and the communication source device 102 may be the same or different.

[0060] The first communication protocol of the communication source device 101 is "Protocol A", and the first communication protocol of the communication source device 102 is "Protocol B". Both communication destination devices 201 and 202 support both Protocol A and Protocol B. Both communication destination devices 201 and 202 run an application supporting Protocol A (referred to as Application A) and an application supporting Protocol B (referred to as Application B). UDP is used as the transport layer protocol between the communication source devices 101 and 102 and the communication processing device 100. UDP is also used as the transport layer protocol between the gateway device 200 and the communication destination devices 201 and 202. TCP is used as the transport layer protocol between the communication processing device 100 and the gateway device 200. However, TCP and UDP are just examples.

[0061] As in the first embodiment, a conversion function unit is provided for each communication destination device. The conversion function unit 110 corresponds to the communication destination device 201, and the conversion function unit 120 corresponds to the communication destination device 202. The communication source device 101 uses the conversion function unit 110 when transmitting a control message to the communication destination device 201, and uses the conversion function unit 120 when transmitting a control message to the communication destination device 202. The communication source device 102 uses the conversion function unit 110 when transmitting a control message to the communication destination device 201, and uses the conversion function unit 120 when transmitting a control message to the communication destination device 202.

[0062] The communication source device 101 generates a control message of protocol A including control data of the communication destination device 201 or 202, and generates a packet by adding a UDP header, an IP header, etc. to the control message. The communication source device 101 sets the destination IP address of the packet to the IP address of the conversion function unit (110 or 120) that performs processing corresponding to the communication destination device to be controlled, one of the communication destination devices 201 or 202. The communication source device 101 sets the UDP destination port number in the packet to a port number for listening for protocol A (1000 in this example). The communication source device 101 sets the UDP source port number to a predetermined port number (2000 in this example). The communication source device 101 outputs the generated packet to the cloud network N1.

[0063] The communication source device 102 generates a control message for protocol B including control data for the communication destination device 201 or 202, and generates a packet by adding a UDP header, an IP header, etc. to the control message. The communication source device 102 sets the destination IP address of the packet to the IP address of the conversion function unit (110 or 120) that performs processing corresponding to the communication destination device to be controlled, one of the communication destination devices 201 or 202. The communication source device 102 sets the UDP destination port number in the packet to a port number for listening for protocol B (1001 in this example). The communication source device 102 sets the UDP source port number to a predetermined port number (2001 in this example). It is assumed that the source port numbers used by the communication source device 102 and the communication source device 101 are different from each other. The communication source device 102 outputs the generated packet to the cloud network N1.

[0064] Both conversion function units 110 and 120 are capable of message conversion processing (conversion processing) for both protocol A and protocol B. Each of conversion function units 110 and 120 waits for packets from communication source device 101 or 102 using both a port number for protocol A (1000 in this example) and a port number for protocol B (1001 in this example).

[0065] When the internal communication unit 113 of the conversion function unit 110 receives a packet addressed to its own IP address and with a destination port number of 1000, the communication protocol processing unit 112 performs conversion processing for protocol A to generate a transfer request message of the second communication protocol. That is, the communication protocol processing unit 112 generates a payload including a control message of protocol A, address information indicating the local IP address of the communication destination device 201, and port number information indicating the port number 1000. Then, the communication protocol processing unit 112 generates a transfer request message of the second communication protocol by adding a header of the second communication protocol to the payload. The method of identifying the local IP address of the communication destination device 201 is the same as the method performed by the IP address identification unit 111 using a conversion table, as in the first embodiment. The transfer request message is a message requesting that the control message of protocol A be transferred to application A of the communication destination device 201. The conversion function unit 110 stores a pair of the source IP address and the source port number of the packet received from the communication source device 101 or 102 in an internal memory for protocol A in the conversion function unit 110.

[0066] When the internal communication unit 113 of the conversion function unit 110 receives a packet addressed to its own IP address and having a destination port number of 1001, the communication protocol processing unit 112 performs conversion processing for protocol B to generate a transfer request message of the second communication protocol. That is, the communication protocol processing unit 112 generates a payload including a control message of protocol B, address information indicating the local IP address of the communication destination device 201, and port number information indicating the port number 1001. Then, the communication protocol processing unit 112 generates a transfer request message of the second communication protocol by adding a header of the second communication protocol to the payload. The method of identifying the local IP address of the communication destination device 201 is the same as the method performed by the IP address identification unit 111 using a conversion table, as in the first embodiment. The transfer request message is a message requesting that the control message of protocol B be transferred to application B of the communication destination device 201. The conversion function unit 110 stores a pair of the source IP address and the source port number of the packet received from the communication source device 101 or 102 in an internal memory for protocol B in the conversion function unit 110.

[0067] The communication protocol processing unit 112 of the conversion function unit 110 adds an HTTPS header, an IP header, etc. to the generated transfer request message to generate a packet addressed to the gateway device 200. The external communication unit 114 of the conversion function unit 110 outputs the generated packet to the wide area network N3.

[0068] The processing of the conversion function unit 120 is similar to that of the conversion function unit 110, except that the communication destination device to be converted is the communication destination device 202. That is, when the internal communication unit 123 of the conversion function unit 120 receives a packet addressed to its own IP address and with a destination port number of 1000, the communication protocol processing unit 122 performs conversion processing for protocol A to generate a transfer request message of the second communication protocol. That is, the communication protocol processing unit 122 generates a payload including a control message of protocol A, address information indicating the local IP address of the communication destination device 202, and port number information indicating the port number 1000. Then, the communication protocol processing unit 122 adds a header of the second communication protocol to the payload to generate a transfer request message of the second communication protocol. The transfer request message is a message requesting that the control message of protocol B be transferred to application A of the communication destination device 202. The conversion function unit 120 stores a pair of the source IP address and the source port number of the packet received from the communication source device 101 or 102 in an internal memory for protocol A in the conversion function unit 120.

[0069] When the internal communication unit 123 of the conversion function unit 120 receives a packet whose destination IP address is the local IP address and whose destination port number is 1001, the communication protocol processing unit 122 performs conversion processing for protocol B to generate a transfer request message of the second communication protocol. That is, the communication protocol processing unit 122 generates a payload including a control message of protocol B, address information indicating the local IP address of the communication destination device 202, and port number information indicating the port number 1001. Then, the communication protocol processing unit 122 generates a transfer request message of the second communication protocol by adding a header of the second communication protocol to the payload. The transfer request message is a message that requests that the control message of protocol B be transferred to application B of the communication destination device 202. The conversion function unit 120 stores a pair of the source IP address and the source port number of the packet received from the communication source device 101 or 102 in an internal memory for protocol B in the conversion function unit 120.

[0070] The communication protocol processing unit 122 of the conversion function unit 120 adds an HTTPS header, an IP header, and the like to the generated transfer request message to generate a packet addressed to the gateway device 200. The external communication unit 124 outputs the generated packet to the wide area network N3.

[0071] The external communication unit 214 of the conversion function unit 210 of the gateway device 200 receives a packet transmitted from the conversion function unit 110 or 120 of the communication processing device 100. The communication protocol processing unit 212 in the conversion function unit 210 reads address information, port number information, and a control message of the first communication protocol (protocol A or protocol B) from the payload of a transfer request message of the second communication protocol included in the received packet. The communication protocol processing unit 212 generates a UDP header, an IP header, etc., and adds the UDP header, IP header, etc. to the control message of the first communication protocol (protocol A or protocol B) to generate a packet. The destination IP address is the local IP address indicated by the address information, and the source IP address is the local IP address of the gateway device 200. The destination port number in the UDP header is the port number indicated by the port number information. The source port number in the UDP header is an arbitrary number or a predetermined number. The internal communication unit 213 of the conversion function unit 210 outputs the generated packet to the local network N2. The output packet is received by the communication destination device 201 or 202 .

[0072] Destination device 201 or 202 receives a packet whose destination IP address is the IP address of the destination device from gateway device 200. Destination device 201 or 202 acquires a control message of the first communication protocol (protocol A or protocol B) included in the received packet, and passes the control data included in the acquired control message to the application indicated by the destination port number in the UDP header. If the destination port number is 1000, it is passed to application A, and if the destination port number is 1001, it is passed to application B. Each application operates according to the passed control data.

[0073] 6 is a diagram showing the sequence between devices when a control message of protocol B is transmitted from a communication source device 102 to a communication destination device 202, along with the schematic structure of a packet transmitted in the sequence. It is assumed that the second communication protocol is HTTPS. It is assumed that the IP address of the communication source device 102 is 192.168.1.123, and the source port number used by the communication source device 102 is 901.

[0074] The communication source device 102 generates a control message for protocol B including control data for the communication destination device 202, and generates a packet P11 by adding a UDP header, an IP header, etc. to the control message. The destination IP address of the packet P11 is the local IP address of the conversion function unit 120 that performs processing corresponding to the communication destination device 202 to be controlled. The source IP address of the packet P11 is the local IP address of the communication source device 102. The destination port number in the UDP header is port number 1001 for listening for protocol B. The source port number in the UDP header is the above-mentioned "901". The communication source device 102 outputs the generated packet P11 to the cloud network N1 (S201).

[0075] The IP address identification unit 121 of the conversion function unit 120 of the communication processing device 100 acquires the local IP address of the communication destination device 202 corresponding to the destination IP address of the received packet based on a conversion table. Furthermore, the communication protocol processing unit 122 of the conversion function unit 120 generates a payload including address information indicating the local IP address of the communication destination device 202, port number information indicating port number 1001, and a control message of protocol B based on the received packet. The communication protocol processing unit 122 generates a TCP header, an IP header, etc. and adds them to the payload. The source IP address of the IP header is the global IP address of the conversion function unit 120, and the destination IP address is the global IP address of the conversion function unit 220 in the gateway device 200. The destination port number of the TCP header is a standby port number of the gateway device 200, and the source port number is an arbitrary number or a predetermined number. Furthermore, the communication protocol processing unit 122 generates a header of the second communication protocol (HTTPS header). The communication protocol processing unit 122 generates a transfer request message (HTTPS message) of the second communication protocol and packet P12 by adding a header to the beginning of the payload. The conversion function unit 120 outputs the generated packet P12 to the wide area network N3 (S202). The conversion function unit 120 stores the pair of source IP address and source port number (192.168.1.123:901) of packet P11 received from the communication source device 102 in an internal memory.

[0076] The gateway device 200 receives a packet P12 transmitted from the conversion function unit 120 of the communication processing device 100. The communication protocol processing unit 212 in the conversion function unit 210 of the gateway device 200 reads address information, port number information, and a control message of protocol B from the payload of the transfer request message of the second communication protocol included in the received packet P12. The conversion function unit 210 generates a UDP header in which the destination port number is port number 1001 indicated by the port number information, and generates an IP header in which the address indicated by the address information (the IP address of the communication destination device 202) is the destination. The source address of the IP header is the local IP address of the gateway device 200. The source port number of the UDP header is port number 1001 for protocol B. The conversion function unit 210 generates a packet P13 by adding the generated UDP header, IP header, etc. to the control message of protocol B. The conversion function unit 210 outputs the generated packet P13 to the local network N2 (S203). The output packet is received by the communication destination device 202 .

[0077] Destination device 202 receives packet P13, the destination IP address of which is the IP address of the destination device 202, from gateway device 200. Destination device 202 passes control data included in the control message of protocol B to application B, which is indicated by port number 1001 in the UDP header of received packet P13. Application B operates in accordance with the acquired control data.

[0078] The above explanation describes the case where a control message of protocol B is sent from the communication source device 102 to the communication destination device 202. However, an example of operation when a response message of protocol B is sent from the communication destination device 202 that received the control message to the communication source device 102 will be described below using Figure 7.

[0079] FIG. 7 is a diagram showing a sequence between devices when a response message of protocol B is transmitted from communication destination device 202 to communication source device 102, together with a schematic structure of a packet transmitted in this sequence.

[0080] The communication destination device 202 generates a packet P14 by adding an IP header destined for the gateway device 200 to a response message of protocol B including response data to the communication source device 102. The communication destination device 202 outputs the generated packet P14 to the local network N2 (S211). The source IP address of the packet P14 is the local IP address of the communication destination device 202, and the destination address is the local IP address of the gateway device 200. The source port number in the UDP header is port number 1001 for protocol B. The destination port number in the UDP header is port number 1001 for protocol B. The gateway device 200 listens on the local network N2 at port number 1001 for protocol B and port number 1000 for protocol A.

[0081] The conversion function unit 210 of the gateway device 200 identifies the source IP address (IP address of the communication destination device 202) of the IP header from the packet P14 received from the communication destination device 202. The conversion function unit 210 also identifies the destination port number (port number 1001 for application B) of the UDP header from the packet P14. The conversion function unit 210 also acquires a response message of protocol B from the packet P14. The conversion function unit 210 generates a payload of the second communication protocol including address information indicating the local IP address of the communication destination device 202, port number information indicating the port number 1001 for protocol B, and the response message of protocol B. The conversion function unit 210 adds an IP header and the like to the payload. The conversion function unit 210 also generates a transfer request message of the second communication protocol and packet P15 by adding a header of the second communication protocol to the payload. The conversion function unit 210 outputs the generated packet P15 to the wide area network N3 (S212). The source IP address in the IP header of packet P15 is the global IP address of gateway device 200, and the destination IP address is the global IP address of communications processing device 100. The UDP destination port number of the packet is a standby port number of communications processing device 100, and the source port number may be any number or a predetermined number. The predetermined number may be the same as the port number used to wait for a control message packet from communications processing device 100.

[0082] The conversion function unit 120 in the communication processing device 100 acquires address information, port number information, and a response message of protocol B from the payload of the transfer request message of the second communication protocol included in the packet P15 received from the gateway device 200. The address information indicates the IP address of the communication destination device 202 corresponding to the conversion function unit 120, and the port number information indicates a port number for protocol B (application B). Therefore, the conversion function unit 120 reads out a pair of the IP address and port number (192.168.1.123:901) of the communication source device 102 stored in an internal memory for protocol B. The conversion function unit 120 generates an IP header in which the read IP address is the destination IP address and its own local IP address is the source IP address. The conversion function unit 120 also generates a UDP header in which the read port number is the destination port number and the port number for protocol B (1001) is the source port number. The conversion function unit 120 generates a packet P16 by adding a UDP header, an IP header, etc. to the response message of protocol B. The conversion function unit 120 transmits the packet P16 to the communication source device 102 in the cloud network N1 (S213). Note that the packet P15 is also received by the conversion function unit 110, but the address information acquired from the received packet P15 does not indicate the IP address of the communication destination device 201 corresponding to the conversion function unit 110, so the conversion function unit 110 discards the received packet P15.

[0083] The communication source device 102 reads the response message of protocol B from the received packet P16 and performs processing based on the response data included in the response message. The communication source device 102 can determine whether the response message is from the communication destination device 201 or 202 based on the source IP address of the packet P16. It can also determine the source application (type of first communication protocol) based on the source port number. An example of processing based on the response data is the same as in the first embodiment.

[0084] 7 has shown an example in which a response message of protocol B is transmitted from communication destination device 202 to communication source device 102, but similar operations are possible when communication destination device 202 receives a control message of protocol A and transmits a response message. Furthermore, the above operations are also possible when communication destination device 202 receives a control message for protocol A or B from communication source device 101 and transmits a response message to communication source device 101. Furthermore, the above operations are also possible when communication destination device 201 receives a control message for protocol A or B from communication source device 101 or 102 and transmits a response message to communication source device 101 or 102.

[0085] As described above, according to this embodiment, the communication processing device 100 includes, in the transfer request message of the second communication protocol, information on a port number corresponding to an application to which a control message should be transferred, among multiple applications running on the destination communication device. This allows the gateway device 200 to transfer the control message of the first communication protocol to the corresponding application, even when multiple applications are running on the destination communication device.

[0086] (Variation 1) The IP address and standby port number of the communication processing device 100 in the second embodiment and the IP address and standby port number of the gateway device 200 may be set by a file created based on user input.

[0087] Fig. 8 is a block diagram of a communication system 2A according to Modification 1 of the second embodiment. Elements that are the same as or correspond to those in Fig. 5 are given the same reference numerals, and detailed description thereof will be omitted. The communications processing device 100 is provided with a function setting unit 180 that sets the conversion function units 110 and 120. The function setting unit 180 sets the conversion function units 110 and 120 (setting IP addresses, port numbers, etc.) based on a system configuration file 181. The system configuration file 181 can be created and updated based on input data from a user terminal 301. The function setting unit 180 causes the user terminal 301 to present an input GUI (Graphical User Interface) screen for creating and updating the system configuration file 181. The function setting unit 180 receives data input from the user terminal 301 and creates the system configuration file 181. A user can provide the input information to the function setting unit 180 by inputting necessary information on the input GUI screen and performing an upload operation.

[0088] The gateway device 200 is provided with a function setting unit 280 that sets the conversion function unit 210. The function setting unit 280 sets the conversion function unit 210 (setting the IP address, port number, etc.) based on a system configuration file 281. The system configuration file 281 can be created and updated based on input data from a user terminal 301. The function setting unit 280 causes the user terminal 301 to present an input GUI screen for creating and updating the system configuration file 281. The function setting unit 280 receives data input from the user terminal 301 and creates the system configuration file 281. A user can provide the input information to the function setting unit 280 by inputting necessary information on the input GUI screen and performing an upload operation. Note that the user terminal 301 for setting the setting function unit 280 and the user terminal 301 for setting the setting function unit 280 may be the same or different user terminals connected to the wide area network N3.

[0089] Figure 9 shows examples of the system configuration file 181 and the system configuration file 281. The function setting unit 180 generates the system configuration file 181 of Figure 9(A) based on user input. The function setting unit 280 also generates the system configuration file 281 of Figure 9(B) based on user input. The "cloud URI" is the URI of the communication processing device 100 when the communication processing device 100 is an HTTPS server.

[0090] Although FIG. 8 shows an example in which function setting units are added to the communication processing device 100 and the gateway device 200 in the second embodiment, similar modifications are possible in the first embodiment as well.

[0091] (Variation 2) In the second embodiment described above, both conversion function units 110 and 120 are compatible with a plurality of first communication protocols (protocol A and protocol B), but each may be compatible with only one first communication protocol. For example, conversion function unit 110 may be compatible with protocol A, and conversion function unit 120 may be compatible with protocol B. In this case, communication destination device 201 may be compatible with only protocol A, and communication destination device 202 may be compatible with only protocol B.

[0092] Alternatively, the conversion function unit 110 may be compatible with protocol B, and the conversion function unit 120 may be compatible with protocol A. In this case, the communication destination device 201 may be compatible with only protocol B, and the communication destination device 202 may be compatible with only protocol A.

[0093] (Variation 3) In the second embodiment described above, there are two communication source devices in the cloud network N1, but the number of communication source devices may be three or more. Furthermore, although there are two communication destination devices in the local network N2, there may be one communication destination device or three or more communication destination devices. The number of communication source devices and communication destination devices does not have to be the same. There may be one communication source device and two or more communication destination devices. There may also be two or more communication source devices and one communication destination device.

[0094] FIG. 10 is a block diagram of a communication system 2B according to a third modification of the second embodiment. Elements that are the same as or correspond to those in FIG. 5 are given the same reference numerals, and detailed description thereof will be omitted. In this example, there are two or more communication source devices and one communication destination device. Since there is one communication destination device, there is also only one conversion function unit in the communication processing device. Except for the difference in the number of communication destination devices and the number of conversion function units, the operation of communication system 2B is the same as that of communication system 2 in FIG. 5.

[0095] 11 is a block diagram of a communication system 2C according to a third modification of the second embodiment. In this example, there are three communication source devices (communication source devices 101, 102, and 103) and three communication destination devices (communication destination devices 201, 202, and 203). Since there are three communication destination devices, there are also three conversion function units (conversion function units 110, 120, and 130) in the communication processing device. The conversion function units 110, 120, and 130 perform processing corresponding to the communication destination devices 201, 202, and 203, respectively. Except for the number of communication destination devices and the number of conversion function units, the operation of the communication system 2C is the same as that of the communication system 2 in FIG. 5.

[0096] Modifications similar to those shown in FIGS. 10 and 11 are also possible for the first embodiment.

[0097] (Variation 4) In the second embodiment described above, the conversion function units 110 and 120 are used in common for all communication source devices, but a dedicated conversion function unit may be provided for each communication source device.

[0098] FIG. 12 is a block diagram of a communication system 2D according to a fourth modification of the second embodiment. Conversion function units 110 and 120 are dedicated to the source device 101 that handles protocol A, and conversion function units 130 and 140 are dedicated to the source device 102 that handles protocol B. When sending a control message from the source device 101 to the destination device 201, the conversion function unit 110 is used, and when sending a control message from the source device 101 to the destination device 202, the conversion function unit 120 is used. When sending a control message from the source device 102 to the destination device 201, the conversion function unit 130 is used, and when sending a control message from the source device 102 to the destination device 202, the conversion function unit 140 is used. The conversion function unit 130 has the same function as the conversion function unit 110, and the conversion function unit 140 has the same function as the conversion function unit 120. An example of the operation of the communication system 2D is the same as that of the second embodiment, and therefore description thereof will be omitted.

[0099] A modification similar to that shown in FIG. 12 is also possible for the first embodiment.

[0100] (Variation 5) In the second embodiment described above, there is one local network, but there may be two or more local networks, in which case a gateway device and a communication processing device are provided for each local network.

[0101] FIG. 13 is a block diagram of a communication system 2E according to a fifth modification of the second embodiment.

[0102] There are two local networks N2_A and N2_B. Communication destination devices 201A and 202A are located in the local network N2_A, and communication destination devices 201B and 202B are located in the local network N2_B. The address systems of the local networks N2_A and N2_B are independent of each other. As shown in the figure, the IP addresses of the communication destination devices 201A and 202A are the same as those of the communication destination devices 201B and 202B, but they may be different.

[0103] A gateway device 200A and a communication processing device 100A are arranged corresponding to the local network N2_A, and a gateway device 200B and a communication processing device 100B are arranged corresponding to the local network N2_B.

[0104] When a control message of the first communication protocol is transmitted from the communication source device 101 to the local network N2_A, a communication processing device 100A and a gateway device 200A are used. When a control message of the first communication protocol is transmitted from the communication source device 101 to the local network N2_B, a communication processing device 100B and a gateway device 200B are used. Conversion function units 110 and 120 of the communication processing device 100A correspond to the communication destination devices 201A and 202A in the local network N2_A, respectively. Conversion function units 130 and 140 of the communication processing device 100B correspond to the communication destination devices 201B and 202B in the local network N2_B, respectively.

[0105] The operation example of the communication system 2E in FIG. 13 is similar to that of the first or second embodiment, and therefore a description thereof will be omitted.

[0106] Although FIG. 13 shows an example in which there are multiple local networks in the second embodiment, there can also be multiple local networks in the first embodiment in the same way.

[0107] (Variation 6) In the first and second embodiments described above, each conversion function unit is fixedly connected to one gateway device, but in this modification, there are multiple gateway devices, and the gateway device to which each conversion function unit is connected can be switched by setting. This reduces the number of conversion function units operating in the communications processing device, making it possible to save memory capacity or power consumption.

[0108] FIG. 14 is a block diagram of a communication system 2F according to a sixth modification of the second embodiment. The settings of the conversion function units 110 and 120 in the communication processing device 100 can be switched by a function setting unit 180. When the conversion function units 110 and 120 are to communicate with the gateway device 200A, the function setting unit 180 sets the conversion function units 110 and 120 using a system configuration file A. On the other hand, when the conversion function units 110 and 120 are to communicate with the gateway device 200B, the function setting unit 180 sets the conversion function units 110 and 120 using a system configuration file B. The global IP addresses of the gateway devices 200A and 200B are different from each other. The settings according to the system configuration files A and B also include settings of the global IP addresses of the gateway devices 200A and 200B. The function setting unit 180 sets the conversion function units 110 and 120 in accordance with instruction data from the user terminal 301. Alternatively, the function setting unit 180 may set the conversion function units 110 and 120 in response to a request from the communication source device 101 .

[0109] When the conversion function units 110 and 120 are configured by the system configuration file A, the conversion function unit 110 performs processing corresponding to the communication destination device 201A of the local network N2_A, and the conversion function unit 120 performs processing corresponding to the communication destination device 202A of the local network N2_A. When the conversion function units 110 and 120 are configured by the system configuration file B, the conversion function unit 110 performs processing corresponding to the communication destination device 201B of the local network N2_B. Also, the conversion function unit 120 performs processing corresponding to the communication destination device 202B of the local network N2_B.

[0110] The operation after the settings in the system configuration file A or B is the same as in the first or second embodiment, and therefore a description thereof will be omitted.

[0111] Although FIG. 14 shows a modified example of the second embodiment, the same modifications are possible in the first embodiment.

[0112] (Variation 7) Each conversion function unit in the communication processing device 100 of the first and second embodiments described above may have a function other than the IP address identification unit and the communication protocol processing unit, thereby enabling the function of each conversion function unit to be expanded.

[0113] 15 is a block diagram of a communication system 2G according to Modification 7 of the second embodiment. The conversion function unit 110 further includes a communication status detection unit 115, a packet aggregation unit 116, and a communication restriction determination unit 117. The conversion function unit 120 further includes a communication status detection unit 125, a packet aggregation unit 126, and a communication restriction determination unit 127.

[0114] The communication status detection unit 115 detects the communication status between the communication processing device 100 (conversion function units 110, 120) and the gateway device 200, or the communication status between the communication source device 101 and the communication destination device 201, and transmits information indicating the communication status to the user terminal 301. The user terminal 301 may display the communication status to allow the user to check the communication status. For example, if an error has occurred and communication has stopped, the user may go to the installation location of the local network N2 and check the status of the communication destination device 201. The function of the communication status detection unit 125 is similar to that of the communication status detection unit 115.

[0115] The packet aggregation unit 116 aggregates multiple packets to be output to the wide area network N3 into one data frame. By aggregating multiple packets into one, overhead can be reduced compared to sending packets separately when the packet size is small, and the effect of reducing communication volume can be expected. The packet aggregation unit 116 aggregates packets into one data frame until it reaches an upper limit of the data size or number of packets that can be aggregated into a data frame. Note that a time limit may be set for aggregation, and if the upper limit is not reached within a certain time, aggregation may be terminated at that point. The packet aggregation unit 126 has the same function as the packet aggregation unit 116.

[0116] The communication restriction determination unit 117 monitors the number of errors in communication, and if the number of errors exceeds a threshold, it terminates or restricts the communication and transmits information indicating this to the communication source device 101, the communication source device 102, or the user terminal 301. For example, the communication restriction determination unit 117 may monitor whether the number of errors in communication, such as the number of HTTPS timeouts or the number of retransmissions, exceeds a threshold in communication between the communication processing device 100 (conversion function units 110, 120) and the gateway device 200. The communication restriction determination unit 127 has the same function as the communication restriction determination unit 117. The operation of the communication restriction determination unit 127 is obvious from the description of the communication restriction determination unit 117, so a detailed description thereof will be omitted.

[0117] The present invention is not limited to the above-described embodiment and each embodiment as it is, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, a configuration in which some components are omitted from all the components shown in the embodiments can also be considered. Furthermore, components described in different embodiments can be appropriately combined. [Explanation of symbols]

[0118] 1,2,2A,2B,2C,2D,2E,2F,2G communication system 100, 100A, 100B Communication processing device 101, 102, 103 Communication source device 110 Conversion function unit 111 IP address identification part 112 Communication protocol processing unit 113 Internal Communications Department 114 External Communications Department 115 Communication status detection unit 116 Packet aggregation unit 117 Communication suppression judgment unit 120, 130, 140 Conversion function unit 121 IP address identification part 122 Communication protocol processing unit 123 Internal Communications Department 124 External Communications Department 125 Communication status detection unit 126 Packet Aggregation Unit 127 Communication suppression judgment unit 180 Function setting section 181 System Configuration Files 200, 200A, 200B Gateway Device 201, 201A, 201B Communication destination device 202, 202A, 202B Communication destination device 203 Communication destination device 210, 220 Conversion function unit 212 Communication protocol processing unit 213 Internal Communications Department 214 External Communications Department 280 Function setting section 281 System Configuration Files 301 User terminal N1 Cloud Network N2 local network N2_A local network N2_B local network N3 Wide Area Network P1, P2, P3, P4, P5, P6 packets P11, P12, P13, P14, P15, P16 packets

Claims

1. a first communication unit that receives a message in a first communication protocol from a first communication device in a first network of a first address system; an address specifying unit that, when a destination address of a message of the first communication protocol matches a first address in the first address system assigned to the first communication unit, specifies an address of the second communication device corresponding to the first address based on correspondence data that associates the first address with an address of a second communication device in a second network of a second address system; a communication protocol processing unit that generates a second communication protocol message that includes address information indicating the address of the second communication device and a message of the first communication protocol in its payload and requests that the message of the first communication protocol be transferred to the second communication device; a second communication unit that transmits a message of the second communication protocol to a gateway device that is capable of communicating with the second communication device in the second network; A communication processing device comprising:

2. the communication protocol processing unit identifies which of a plurality of port numbers corresponding to a plurality of applications running on the second communication device a destination port number of the message of the first communication protocol matches; the communication protocol processing unit includes port number information indicating the identified port number in the payload, The message of the second communication protocol is a message requesting that the message of the first communication protocol be transferred to an application indicated by the port number information running on the second communication device. The communication processing device according to claim 1 .

3. The communication protocol processing unit generates a message of the second communication protocol by adding a header of the second communication protocol to the payload.

3. The communication processing device according to claim 1.

4. The message of the first communication protocol includes control data for controlling the second communication device.

3. The communication processing device according to claim 1.

5. The second communication protocol is a communication protocol higher than the first communication protocol in the communication protocol hierarchy.

3. The communication processing device according to claim 1.

6. The second communication protocol is HTTPS. The communication processing device according to claim 5 .

7. a plurality of conversion function units each including the first communication unit, the address identification unit, the communication protocol processing unit, and the second communication unit; the plurality of conversion function units respectively process the plurality of second communication devices in the second network; The first communication units of the plurality of conversion function units are assigned different first addresses.

3. The communication processing device according to claim 1.

8. The plurality of second communication devices exist in the plurality of second networks each having a different second address system. The communication processing device according to claim 7 .

9. receiving a message in a first communication protocol from a first communication device in a first network in a first address system by a communication unit; when a destination address of a message of the first communication protocol matches a first address in the first address system assigned to the communication unit, identifying an address of the second communication device corresponding to the first address based on correspondence data that associates the first address with an address of a second communication device in a second network of a second address system; generating a message of a second communication protocol including address information indicating an address of the second communication device and a message of the first communication protocol in a payload, the message requesting that the message of the first communication protocol be transferred to the second communication device; transmitting a message in the second communication protocol to a third network; receiving a message in the second communication protocol from the third network; processing the second communication protocol message to obtain the address information and the first communication protocol message; a message in the first communication protocol addressed to the address of the second communication device indicated by the acquired address information, the message being transmitted to the second communication device in the second network; Communication method.

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