WO2014010189A1

WO2014010189A1 - Proxy device, communication system, program

Info

Publication number: WO2014010189A1
Application number: PCT/JP2013/004016
Authority: WO
Inventors: 浩基數野; 敏章中尾
Original assignee: パナソニック株式会社
Priority date: 2012-07-13
Filing date: 2013-06-27
Publication date: 2014-01-16
Also published as: CN104429025A; JP2014022820A

Abstract

A proxy device is provided with a first communication interface unit, a second communication interface unit, and a processing unit. The first communication interface unit communicates with a server connected to a first communication network. The second communication interface unit communicates with a subsystem connected to a second communication network. When the first communication interface unit has received a packet including a plurality of information items requested by the server to the subsystem, the processing unit disseminates the individual requested information items and transmits the requested information to the subsystem via the second communication interface unit.

Description

Proxy device, communication system, program

The present invention relates to a proxy device that is interposed between different communication networks and controls transmission of information between different communication networks, a communication system using the proxy device, and a program for realizing the proxy device.

Conventionally, when communication is performed between a first communication network such as the Internet and a second communication network such as a LAN (Local Area Network), the first communication network and the second communication network In order to absorb the difference in protocol between the two, a technique using a proxy device has been proposed (see, for example, Japanese Patent Publication No. 2007-166423 (hereinafter referred to as “Document 1”)). Document 1 describes a technique of performing communication via a proxy device (SIP Proxy) connected to the Internet in order to perform communication between the communication devices connected to the LAN via the Internet. That is, the communication device enables data transmission through networks of different protocols by performing encapsulation.

In addition to the above-described configuration, the proxy device transmits request information from one of the two communication devices connected to a different communication network, and performs processing on the request information in the other communication device and responds. It is also used for protocol conversion when information is returned to the one communication device. In a communication system having such a configuration, when a plurality of communication devices using different protocols are provided for each proxy device, a large amount of request information or response information may occur.

In such a case, if one packet is assigned to each of request information and response information and communication is performed, the communication amount of the communication network connected to the proxy device increases, and the communication processing amount for transmitting and receiving the packet Will increase. That is, a load is applied to the communication device and the proxy device, and the communication amount of the communication network increases, so that the service of the communication system may be stopped in some cases.

It is an object of the present invention to provide a proxy device that can avoid a service stop of a communication system by lowering the communication amount of the communication network than before when performing communication between different communication networks. Furthermore, an object of the present invention is to provide a communication system using the proxy device and to provide a program for realizing the proxy device.

The proxy device according to the present invention communicates between a first communication interface unit that communicates with a server connected to a first communication network and a subsystem that is connected to a second communication network. Two communication interface units, and when the first communication interface unit receives a packet including a plurality of request information for the subsystem from the server, the packet is expanded into individual request information, and the second And a processing unit that transmits the request information to the subsystem through a communication interface unit.

In this proxy device, the first communication interface unit receives the request information encapsulated by a first communication protocol that is a push type, and the second communication interface unit is an open type. It is preferable to communicate with the subsystem using the communication protocol No. 2.

In this proxy apparatus, it is preferable that the processing unit determines an order in which the individual request information is transmitted to the subsystem according to a time at which the first communication interface unit receives the packet from the server.

In this proxy apparatus, it is preferable that the second communication interface unit adjusts the timing of transmitting the request information to the subsystem so that the request information is not lost according to the processing capability of the subsystem.

In this proxy device, the processing unit includes a request information buffer that holds a plurality of request information waiting to be transmitted, and a rank storage unit in which types of request information and priority levels to be transmitted to the subsystem are registered in advance. And when the priority of the request information received by the first communication interface unit is higher than the priority of the plurality of transmission-waiting request information held in the request information buffer, It is preferable that the request information received by the communication interface unit is transmitted to the subsystem first.

In this proxy device, when there are a plurality of request information to be transmitted to the same subsystem, the processing unit collects the plurality of request information into one packet and transmits the packet to the corresponding subsystem. It is preferable.

In the proxy device, the second communication interface unit has a function of receiving response information for the request information from the subsystem, and the first communication interface unit is configured to respond to the processing capability of the server. It is preferable to adjust the timing for transmitting the response information to the server so that the information is not lost.

In this proxy apparatus, the processing unit receives the response information for the request information from the subsystem when the second communication interface unit includes a plurality of response information to be transmitted to the same server. It is preferable that the pieces of response information are collected into one packet and transmitted to the corresponding server.

A communication system according to the present invention includes the above-described proxy device, a server connected to the proxy device via a first communication network, and a subsystem connected to the proxy device via a second communication network. Request information issued by the server is transmitted to the subsystem via the proxy device, and response information for the request information from the subsystem is transmitted to the server via the proxy device. Features.

In this communication system, it is preferable to further include an overall management device that performs at least one of control and monitoring for the server, the subsystem, and the proxy device.

A program according to the present invention communicates between a first communication interface unit that communicates a computer with a server connected to a first communication network and a subsystem connected to a second communication network. And when the first communication interface unit receives a packet including a plurality of request information for the subsystem from the server, expands the packet into individual request information, and And a processing unit that transmits the request information to the subsystem through two communication interface units. The present invention is not limited to a program, and may be a computer-readable recording medium that records the program.

According to the configuration of the present invention, when performing communication between different communication networks, a plurality of request information is transmitted in a single packet, so the communication amount of the communication network is reduced as compared with the conventional network. Therefore, it is possible to avoid the suspension of the communication system service.

Preferred embodiments of the invention are described in more detail. Other features and advantages of the present invention will be better understood with regard to the following detailed description and accompanying drawings.
1 is a block diagram illustrating a communication system according to a first embodiment. 1 is a diagram illustrating a configuration example of a communication system according to a first embodiment. FIG. 5 is an operation explanatory diagram illustrating a processing procedure of the communication system according to the first embodiment in a sequence diagram. 6 is a diagram illustrating an operation of a main part of a communication system according to Embodiment 2. FIG.

(Embodiment 1)
In the embodiment described below, a communication system having the configuration shown in FIG. 2 will be described as an example. The communication system shown in FIG. 2 includes a plurality of servers 20 connected to a first communication network NT1 such as the Internet, and a plurality of subsystems 30 connected to a second communication network NT2. . The second communication network NT2 is a LAN (Local Area Network), and the subsystem 30 includes terminal devices (not shown) connected to the second communication network NT2, respectively. A communication system different from the communication system shown in FIG. 2 is constructed.

¡By constructing a hierarchical communication system in this way, a large-scale communication system can be constructed. For example, even when there are a large number of monitoring targets and control targets, such as when monitoring and controlling equipment in a building such as a building is performed using communication technology, the communication system is hierarchized. It is possible to respond easily.

Data is transmitted via the proxy device 10 between the first communication network NT1 and the second communication network NT2. The proxy device 10 in the illustrated example has a function of relaying data transmission between the server 20 connected to the first communication network NT1 and the second communication network NT2, and the proxy device 10 and the first communication network There is a firewall 40 between NT1.

The illustrated configuration example shows a configuration in which a plurality of subsystems 30 share the proxy device 10. Although only one proxy device 10 is shown in the figure, a plurality of proxy devices 10 are connected to the first communication network NT1, and a plurality of proxy devices 10 are connected to the first communication network NT1 via the second communication network NT2. Each subsystem 30 may be connected. In addition, although it is possible to connect one subsystem 30 to one proxy apparatus 10, this embodiment assumes only when a plurality of subsystems 30 are connected to one proxy apparatus 10. .

In a wide area where a plurality of facilities exist, using the communication system described above enables monitoring and control of equipment (not shown) arranged for each facility. For example, when a plurality of subsystems 30 are constructed in a facility, one or more proxy devices 10 are provided for each facility, and each proxy device 10 is connected to the second communication network NT2 to A communication system is constructed. Therefore, the server 20 connected to the first communication network NT1 can monitor and control a large number of devices arranged in the facility through the subsystem 30.

As an example, assume that lighting equipment is managed for each building or area of public facilities in one city. The lighting control system is constructed as the subsystem 30 in units of buildings and areas. In such a system, if the proxy device 10 is provided for each lighting control system, an organization (for example, a city office) that operates public lighting in the city can connect the lighting control system for the entire city to the first communication network NT1. It becomes possible to manage all at once. In other words, if the Internet is used for the first communication network NT1, it is possible to control lighting device lighting / lighting off and monitor lighting device lighting time from the server 20 via the Internet. .

In this case, a terminal device connected to any one of the servers 20 or the first communication network NT1 is used as a general management device that performs at least one of monitoring and control of the proxy device 10, the server 20, and the subsystem 30. By using such an overall management apparatus, it becomes possible to collectively manage the lighting control system (at least one of control and monitoring) existing in various places in the city by the overall management apparatus.

As shown in FIG. 1, the proxy device 10 includes a first communication interface unit (hereinafter referred to as “communication I / F”) 11 for connecting to the first communication network NT1, a second communication interface unit And a second communication I / F 12 for connecting to the communication network NT2. The first communication I / F 11 performs communication using a push-type first communication protocol, and the second communication I / F 12 performs communication using an open-type second communication protocol. Between the first communication I / F 11 and the second communication I / F 12, a processing unit that transmits request information from the server 20 to the subsystem 30 and returns response information from the subsystem 30 to the server 20. 100 is provided. The proxy device 10 is a computer on which a CPU (Central Processing Unit) and a memory are mounted, and performs various processes by executing a program. In the present embodiment, a computer-readable recording medium that records the program may be used.

As the first communication protocol, for example, a protocol that enables Comet communication is used, and by long polling, it is possible to transmit data from the server 20 to the proxy device 10 beyond the firewall 40. However, the time during which the downstream communication path from the server 20 to the proxy device 10 is opened between the server 20 and the proxy device 10 is limited. If no data is transmitted within the limited time, a timeout occurs, and the downstream communication path from the server 20 to the proxy device 10 is disconnected after the timeout. Communication from the proxy device 10 to the server 20 is required to reopen the communication path.

The server 20 transmits request information in the application layer to the subsystem 30. That is, the server 20 issues request information for the subsystem 30 in the application processing unit 200, and sends the request information to the first communication network NT1 through the communication processing unit 201. Further, the server 20 receives the response information from the subsystem 30 through the proxy device 10 when receiving the response information to the request information from the subsystem 30. The proxy device 10 can communicate with one or more subsystems 30.

Assuming that the proxy device 10 does not exist, the server 20 transmits request information and response information to and from each subsystem 30 when there are a plurality of subsystems 30. This leads to an increase in the number of packets transmitted through the communication network NT1. That is, since the server 20 must transmit a packet including a payload, a header, and a trailer, which are the contents of request information or response information, for each subsystem 30, the packet transmitted through the first communication network NT1. The number will increase.

In the present embodiment, when data is transmitted from the server 20 to the proxy device 10, the request information to be transmitted even when there are a plurality of subsystems 30 by collecting data for request information to the subsystems 30. Can be transmitted in one packet. That is, the data to be transmitted to the subsystem 30 is encapsulated in the payload of the packet transmitted from the server 20 to the proxy device 10 through the first communication network NT1.

Therefore, the communication processing unit 201 of the server 20 has a function of generating a payload by collecting request information to be transmitted to the subsystem 30. In addition, the proxy device 10 includes a request processing unit 101 that expands the payload received from the server 20 into request information for each subsystem 30.

On the other hand, in upstream communication in which data is transmitted from the proxy device 10 to the server 20, a packet having response information from each subsystem 30 as a payload is transmitted. That is, the proxy device 10 transmits the response information from the subsystem 30 received through the second communication network NT2 to the server 20 as a packet of the first communication network NT1.

More specific description will be given below. Here, it is assumed that the initial processing of Comet communication (for example, Bayeux) has already been completed between the proxy device 10 and the server 20. That is, in order to establish Comet communication, a request for Comet communication is transmitted to the target server 20 to which the proxy device 10 intends to communicate, and the initial communication for Comet communication between the server 20 and the proxy device 10 is performed. It is assumed that processing has been performed.

As described above, the server 20 issues request information to the subsystem 30 and performs processing for response information from the subsystem 30 and communication for connecting to the first communication network NT1. And a processing unit 201. The application processing unit 200 corresponds to an application layer in the hierarchical communication model. The application processing unit 200 issues request information for the subsystem 30 when an event is input, and provides appropriate services such as display and notification for response information from the subsystem 30.

An event is, for example, a switch operation by a user, a state change of a sensor (not shown), and a service means, for example, presentation of information to a monitor device (not shown), storage of information in a storage device (not shown) . Further, an event input to the application processing unit 200 and a service provided by the application processing unit 200 may be received from a device that communicates with the server 20. For example, response information received from the subsystem 30 can be used as an event, or request information transmitted to the subsystem 30 can be used as a service.

Here, description will be made assuming that an event is input to the application processing unit 200 of the server 20 and the application processing unit 200 issues request information to each of the three subsystems 30 in response to the input event. The application processing unit 200 includes a relationship storage unit (not shown) that stores a group of events and a group of request information for the subsystem 30 in association with each other, and refers to the relationship storage unit when an event is input. As a result, the request information to the subsystem 30 is issued. Request information issued by the application processing unit 200 is input to the communication processing unit 201.

The communication processing unit 201 includes a buffer (not shown) that temporarily stores request information. When the request information is input from the application processing unit 200, the communication processing unit 201 holds the request information in the buffer and measures the reception time. . Further, the communication processing unit 201 holds all request information input from the application processing unit 200 in the buffer within a period in which the reception time is counted. When the reception time expires, the communication processing unit 201 transmits the request information held in the buffer as a whole. That is, the communication processing unit 201 uses the request information held in the buffer as a payload, generates a packet with a header and trailer for transmission to the proxy device 10, and transmits the packet to the proxy device 10.

The communication processing unit 201 resets a built-in clock (not shown) that counts the reception time when sending the request information held in the buffer to the first communication network NT1, and receives the next request from the application processing unit 200. Wait for information. That is, when the request information is input from the application processing unit 200 after resetting the built-in clock, the communication processing unit 201 starts counting the reception time, and the request information input within the period in which the reception time is timed. Are sent to the first communication network NT1.

FIG. 2 shows only one proxy device 10, but a plurality of proxy devices 10 are often used. Therefore, the application processing unit 200 desirably delivers the destination information of the proxy device 10 to the communication processing unit 201 together with the request information in order to identify the destination proxy device 10 to which the request information is transmitted. If the system has only one proxy device 10, the destination information can be omitted.

As described above, when a plurality of pieces of request information are generated during the reception time counting, the plurality of pieces of request information are combined into one, and the communication processing unit 201 generates a packet having the combined request information as a payload, Transfer to the proxy device 10 indicated by the information. Accordingly, the payload of this packet can include request information addressed to one or more subsystems 30. That is, the server 20 encapsulates a plurality of request information, and transmits the created packet to the proxy device 10.

On the other hand, the proxy device 10 decapsulates the packet from the server 20. When the first communication I / F 11 of the proxy device 10 receives the packet from the server 20, the first communication I / F 11 extracts the header and the payload from the packet and delivers them to the request processing unit 101. The header includes information for identifying the server 20 that is the transmission source, and the payload includes a subsystem 30 that is a counterpart to which the request information is transmitted, and request information for the subsystem 30.

The request processing unit 101 extracts the identification information (address, etc.) of the transmission source server 20 from the packet header, and extracts the identification information (address, etc.) of the subsystem 30 and the request information for the subsystem 30 from the packet payload. . That is, the request processing unit 101 restores a plurality of request information in the packet payload. Here, for example, an IP address is used as the identification information of the server 20, but the identification information of the subsystem 30 may be information that can be identified in the second communication network NT2 in addition to the IP address, the MAC address, and the like. .

As described above, the request processing unit 101 extracts the request information for each subsystem 30, the identification information of the subsystem 30, and the identification information of the transmission source server 20 from the packet received from the server 20, and requests the request. Store in the information buffer 102. Further, the request processing unit 101 delivers these pieces of information from the request information buffer 102 to the second communication I / F 12. The second communication I / F 12 generates a packet to be transmitted for each subsystem 30 using the information delivered from the request information buffer 102 by the request processing unit 101. That is, a packet including request information for each subsystem 30 is transmitted to the second communication network NT2 with the transmission source as the server 20 and the designated subsystem 30 as the transmission destination.

Here, the request processing unit 101 delivers information to the second communication I / F 12 in the order in which the information is received from the first communication I / F 11. The order in which the request processing unit 101 delivers information to the second communication I / F 12 is determined by FIFO (First In First Out) processing, or the request processing unit 101 receives information from the first communication I / F11. It is determined using time (this point will be described in Embodiment 2).

By the way, when the server 20 transmits request information to the subsystem 30, it expects response information from the subsystem 30. When the proxy device 10 relays communication between the server 20 and the subsystem 30, it is necessary to return response information received by the proxy device 10 from the subsystem 30 to the server 20 that issued the request information to the subsystem 30. is there. Therefore, the proxy device 10 includes a response information buffer 104 that stores the identification information of the transmission source server 20 that issued the request information in association with the request identification information assigned for each request information.

The response information buffer 104 stores a set of (request identification information, server identification information) for each request information to the subsystem 30. Since the request identification information only needs to be able to identify the request information, for example, a number indicating the order of the request information handled by the request processing unit 101 is used. The request identification information is added to a packet when request information is transmitted from the proxy device 10 to the subsystem 30, and is also added to a packet when response information is returned from the subsystem 30 to the proxy device 10. Therefore, the proxy device 10 that has received the response information can acquire the identification information of the server 20 to which the response information should be returned by collating the request identification information with the response information buffer 104, and return the response information to the appropriate server 20. It becomes possible to do.

The proxy device 10 transmits the request information received from the server 20 to the subsystem 30, and the subsystem 30 performs processing according to the request information received from the proxy device 10. Here, the subsystem 30 includes a communication processing unit 301 for communicating through the second communication network NT2, and an application processing unit 300 for processing request information and issuing response information. The subsystem 30 has a function of storing identification information of the proxy device 10 that has received the request information, and returning response information for the request information to the proxy device 10 in which the identification information is stored.

The request information transmitted from the proxy device 10 to the subsystem 30 is accompanied by request identification information. When the subsystem 30 receives the request information from the proxy device 10, the request identification is made together with the proxy device 10 to which the response information is returned. It also stores information. Further, when returning the response information to the proxy device 10, the subsystem 30 adds the request identification information received accompanying the request information.

On the other hand, when the subsystem 30 designates the proxy device 10 and returns response information, the second communication I / F 12 of the designated proxy device 10 receives the response information and request identification information from the subsystem 30. The second communication I / F 12 gives the response information and the request identification information received from the subsystem 30 to the response processing unit 103 provided in the proxy device 10. The response processing unit 103 extracts the identification information of the server 20 to which the response information should be returned using the request identification information.

The response processing unit 103 generates data for transmitting the response information received from the subsystem 30 to the server 20 using the extracted identification information of the server 20 and transmits the data to the server 20 through the first communication I / F 11. Send the packet to be sent. That is, since the first communication network NT1 performs communication using the first communication protocol (for example, Comet communication), the proxy device 10 adapts the packet including the response information from the subsystem 30 to the first communication protocol. Assemble.

The response processing unit 103 has the same function as the communication processing unit 201 of the server 20, and when there are a plurality of response information to be transmitted to one server 20 (the same server 20), the response information Are sorted for each server 20. Response information to be collected is not limited to response information received from one subsystem 30, but may be response information received from a plurality of subsystems 30. The collected response information is temporarily stored in the response information buffer 104. The response processing unit 103 first stores response information from a state in which no response information is stored in the response information buffer 104, and then collects the response information stored within a predetermined waiting time.

When there is only one server 20, the response processing unit 103 does not need to extract the identification information of the server 20 and only needs to transmit the response information from the subsystem 30 to one known server 20. . Further, the response processing unit 103 may hold only one piece of response information in the response information buffer 104.

As described above, when the response processing unit 103 summarizes the response information for each destination server 20, the first communication I / F 11 converts the response information collected for each server 20 into one packet, and the first communication network. Send to NT1. Receiving this packet, the server 20 causes the communication processing unit 201 to extract individual response information from the packet. Therefore, the server 20 can provide various services using the response information received for the request information.

As described above, the server 20 collects a plurality of pieces of request information for the subsystems 30 and transmits them to the proxy device 10 in one packet. The proxy device 10 converts the packets into request information for each subsystem 30. expand. In addition, the proxy device 10 transmits response information from the plurality of subsystems 30 in one packet for each server 20 to be returned, and the server 20 expands the packet into individual response information. Therefore, the amount of communication (number of communication processes) performed between the server 20 and the proxy device 10 through the first communication network NT1 is compared with the case where a packet is transmitted for each request information and each response information. Can be greatly reduced.

The operations described above are summarized in FIG. First, when the application processing unit 200 of the server 20 issues a plurality of request information, the communication processing unit 201 integrates these request information (P1). The integrated request information is transmitted as one packet to the proxy device 10 (P2). The proxy device 10 expands the request information included in the packet (P3), and transmits the expanded request information to the subsystem 30 (P4). When the subsystem 30 receives the request information from the proxy device 10, the application processing unit 300 processes the request information (P5), issues response information, and transmits it to the proxy device 10 (P6). When a plurality of response information exists for one server 20, the proxy device 10 integrates these response information for each server 20 (P7), and integrates the response information into the corresponding server. 20 (P8).

As described above, when the server 20 issues a plurality of pieces of request information, since the request information is collected into one packet, it is possible to reduce the amount of communication in the first communication network NT1. Become. In addition, the communication processing amount is reduced in the communication processing unit 201 and the first communication I / F 11. As a result, it is possible to avoid a service stop provided by the communication system.

(Embodiment 2)
In the first embodiment, a case in which a number indicating the order of request information handled by the request processing unit 101 is used as request identification information accompanying the request information is taken as an example. However, when request information generated in a short time is processed in time order, it is necessary to process the request information in the order received by the proxy device 10 in order to operate the system correctly and stably. There is a case.

In this embodiment, the time when the first communication I / F 11 receives a packet according to the first protocol from the server 20 is added to the request information, so that the subsystem 30 is in the order in which the proxy device 10 received the request information. It is possible to send request information to. As the time at which the first communication I / F 11 receives the packet, the time measured by a built-in clock (not shown) of the proxy device 10 is used, or the time at which the server 20 transmits the packet is used. However, when there are a plurality of servers 20, the time measured by the built-in clocks of all the servers 20 is matched using the time measured by a standard time server (for example, an NTP server) provided separately. It is necessary to keep.

Now, it is assumed that the proxy device 10 receives two packets each including request information from two of the three servers 20 connected to the first communication network NT1. Here, as shown in FIG. 4, one packet includes three request information D11, D12, and D13, and the other packet includes three request information D21, D22, and D23. And In the following, it is assumed that request information D11, D12, D13 included in one packet is issued in this order, and request information D21, D22, D23 included in the other packet is issued in this order.

The request information D11, D12, D13 of one packet and the request information D21, D22, D23 of the other packet are expanded into individual request information D11, D12, D13, D21, D22, D23 by the request processing unit 101, and the request It is held in the information buffer 102. When the time when the first communication I / F 11 of the proxy device 10 receives one packet precedes the time when the other packet is received, the request information buffer 102 stores the request information D11 as shown in FIG. , D12, and D13 are stored earlier than the request information D21, D22, and D23 (representing that the time is earlier in the upper side).

In the illustrated example, a case is shown in which the first communication I / F 11 receives the other packet one second after receiving the one packet. In addition, request information included in one packet also has a time order, indicating that the left side of the figure is earlier in time. That is, the request information D11 is issued before the request information D12, and the request information D22 indicates that it is issued before the request information D23.

When the first communication I / F 11 receives a packet from the server 20, the processing unit 100 of the proxy device 10 acquires the reception time of the request information, and stores the request information in the request information buffer 102 from the earlier reception time. . When a plurality of pieces of request information are included in one packet, the request information is stored in the request information buffer 102 in consideration of the order in which the request information is issued in addition to the reception time. The request information buffer 102 stores reception time information including the reception time and the order in association with the request information. The request information stored in the request information buffer 102 in this way is transmitted to the subsystem 30 in the order stored in the request information buffer.

When transmitting the request information to the subsystem 30, the proxy device 10 delivers the issued identification information of the server 20 to the subsystem 30 as in the first embodiment. At this time, not only the identification information of the server 20 but also the reception time information associated with the request information may be delivered to the subsystem 30 together.

As described above, by using the reception time information, even when request information is received from a plurality of servers 20 within a short time, the request information can be sequentially delivered to the subsystem 30. Other configurations and operations are the same as those of the first embodiment.

(Embodiment 3)
In the present embodiment, an operation for preventing overflow of request information in the subsystem 30 when request information transmitted from the proxy apparatus 10 to the subsystem 30 temporarily becomes excessive will be described. The overflow of request information may occur when request information for a specific subsystem 30 is generated in a concentrated manner or when the processing capacity of the subsystem 30 is low. When the request information overflows in the subsystem 30, the overflow request information is lost without being processed in the subsystem 30.

In preparation for such a case, the second communication I / F 12 in the proxy device 10 has a function of transmitting request information according to the processing capability of the subsystem 30. For example, when the subsystem 30 has only the processing capability to process request information one by one, the second communication I / F 12 transmits one request information to the subsystem 30 and receives response information for the request information. After that, the next request information is transmitted. By performing such an operation, it becomes unnecessary to simultaneously process a plurality of request information in the subsystem 30, and it is possible to prevent the loss of the request information.

In the above-described example, the case where the subsystem 30 has only the processing capability to process the request information one by one has been described. However, if the processing capability of the subsystem 30 is high, the second communication I / F 12 performs the processing of the subsystem 30. A plurality of pieces of request information may be transmitted simultaneously within the capability range. In this case, the packet transmitted from the proxy device 10 to the subsystem 30 may adopt either a format including request information one by one or a format including a plurality of request information. In any case, it is desirable that the number of request information to be transmitted per unit time for each subsystem 30 can be set in the proxy device 10 in advance. Alternatively, the total amount of request information transmitted per unit time may be set in advance for each subsystem 30.

When a plurality of request information is transmitted from the proxy device 10 to the subsystem 30 within a unit time, the proxy device 10 receives the response information for these request information from the subsystem 30 and then transmits the next request information. To do. By this operation, overflow of request information in the subsystem 30 is prevented. Other configurations and operations are the same as those of the above-described embodiment.

(Embodiment 4)
In the above-described embodiment, the proxy device 10 transmits the request information to the subsystem 30 in the order in which the request information is received. However, depending on the type of the subsystem 30 and the type of request information, the request information received later from the server 20 by the proxy device 10 must be transmitted to the subsystem 30 in preference to the request information waiting for transmission. There is. In preparation for such a case, in the present embodiment, the proxy apparatus 10 can set the priority order according to at least one of the type of the subsystem 30 and the type of request information. That is, a rank storage unit (not shown) that registers at least one of the type of the subsystem 30 that transmits request information and the type of request information in association with the priority order in the processing unit 100 of the proxy device 10. Is provided. The processing unit 100 checks the request information (at least one of the type of the subsystem 30 and the type of request information) received by the first communication I / F 11 from the server 20 with the rank storage unit. If the request information received from the server 20 has higher priority than the request information held in the request information buffer 102, the request information received from the server 20 is held in the request information buffer 102. The request information is sent to the subsystem 30 in preference to the queue of request information.

In the above-described operation, priority is set for at least one of the type of subsystem 30 and the type of request information. On the other hand, in the request information buffer 102, when the number of request information to be transmitted to a specific subsystem 30 exceeds a threshold, an operation for increasing the priority of the request information to be transmitted to the specific subsystem 30 is performed. It may be adopted.

In the present embodiment, the request information stored in the request information buffer 102 is interrupted in the order of request information, and other request information can be transmitted to the subsystem 30 with priority. Therefore, when the subsystem 30 includes a device with a high degree of urgency, the request information can be transmitted at an appropriate timing, for example, when ensuring the processing stability of the proxy device 10 or when transmitting a survival confirmation command. become. Other configurations and operations are the same as those of the above-described embodiments.

(Embodiment 5)
In each embodiment described above, when request information is transmitted from the proxy device 10 to the subsystem 30, one request information is included in one packet. However, as described in the third embodiment, it is also possible to transmit a single packet to be transmitted to one subsystem 30 by including a plurality of request information.

Therefore, the second communication I / F 12 in the proxy device 10 according to the present embodiment includes a plurality of request information to be transmitted to the same subsystem 30 in the request information held in the request information buffer 102. , A function of transmitting a plurality of pieces of request information in one packet. That is, the second communication I / F 12 includes request information to be transmitted to the same subsystem 30 in the request information queued in the request information buffer 102, and the number exceeds the predetermined threshold. A function of collecting a plurality of pieces of request information on condition that the request information is present. The request information in the queue means request information held in the request information buffer 102 within a predetermined reception time. The second communication I / F 12 transmits the collected request information in one packet, and the subsystem 30 receiving this packet expands a plurality of request information contained in the packet into individual request information. The processing in the application processing unit 300 is executed.

As described above, in the present embodiment, a plurality of pieces of request information are collected in the packet transmitted from the proxy device 10 to the subsystem 30, so that the amount of communication in the second communication network NT2 is reduced and communication is performed. The number of processes is also reduced. Other configurations and operations are the same as those of the above-described embodiment.

(Embodiment 6)
In the third embodiment, it has been described that the request information may overflow depending on the processing capability of the subsystem 30, but the server 20 may similarly overflow in the response information. Although it is conceivable to provide a load balancer in order to distribute the load of the server 20, it is not practical because the cost increases.

Therefore, in this embodiment, the proxy device 10 has a function of adjusting the timing at which the response information is returned to the server 20 according to the processing capability of the server 20. When the server 20 has only the processing ability to receive response information one by one, the first communication I / F 11 transmits one response information to the server 20 and confirms that the server 20 has received this response information. Later, the operation of transmitting the next response information is performed. By performing this operation, the server 20 does not receive a plurality of response information at the same time, and the loss of response information is prevented.

If the server 20 can simultaneously receive a plurality of response information, the number of response information to be transmitted to the server 20 per unit time may be set in the proxy device 10 in advance. Alternatively, the total amount of response information transmitted per unit time may be set in advance for each server 20.

As described above, by adjusting the timing at which the proxy device 10 transmits the response information to the server 20, an overflow of the response information at the server 20 is prevented. Other configurations and operations are the same as those of the above-described embodiment.

While the invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the invention, ie, the claims.

Claims

A first communication interface unit for communicating with a server connected to the first communication network;
A second communication interface unit communicating with a subsystem connected to the second communication network;
When the first communication interface unit receives a packet including a plurality of request information for the subsystem from the server, the packet is expanded into individual request information, and the request information is transmitted through the second communication interface unit. And a processing unit that causes the subsystem to transmit the proxy device.
The first communication interface unit receives the request information encapsulated by a first communication protocol that is a push type from the server,
The proxy apparatus according to claim 1, wherein the second communication interface unit communicates with the subsystem using a second communication protocol that is an open type.
The said processing part determines the order which transmits each said request information to the said subsystem according to the time when the said 1st communication interface part received the said packet from the said server. Proxy device.
The second communication interface unit adjusts the timing of transmitting the request information to the subsystem so that the request information is not lost according to the processing capability of the subsystem. The proxy device according to any one of the above.
The processor is
A request information buffer for holding a plurality of request information waiting to be transmitted;
A rank storage unit in which the type of request information and the priority to be transmitted to the subsystem are registered in advance;
When the priority of the request information received by the first communication interface unit is higher than the priority of the plurality of request information waiting for transmission held in the request information buffer, the first communication interface 5. The proxy device according to claim 1, wherein the request information received by a unit is transmitted to the subsystem first.
When there are a plurality of pieces of request information to be transmitted to the same subsystem, the processing unit combines the plurality of request information into one packet and transmits the packets to the corresponding subsystem. The proxy device according to any one of claims 1 to 5.
The second communication interface unit has a function of receiving response information to the request information from the subsystem;
The first communication interface unit adjusts the timing of transmitting the response information to the server so that the response information is not lost according to the processing capability of the server. 2. The proxy device according to claim 1.
When the second communication interface unit receives response information for the request information from the subsystem and there is a plurality of response information to be transmitted to the same server, the processing unit receives the plurality of response information. The proxy device according to any one of claims 1 to 7, wherein the proxy device transmits the packets together to the corresponding server.
The proxy device according to any one of claims 1 to 8,
A server connected to the proxy device via a first communication network;
A subsystem connected to the proxy device via a second communication network,
Request information issued by the server is transmitted to the subsystem via the proxy device, and response information for the request information from the subsystem is transmitted to the server via the proxy device. Communications system.
The communication system according to claim 9, further comprising an overall management device that performs at least one of control and monitoring for the server, the subsystem, and the proxy device.
Computer
A first communication interface unit that communicates with a server connected to a first communication network; a second communication interface unit that communicates with a subsystem connected to a second communication network; When the first communication interface unit receives a packet including a plurality of request information for the subsystem from a server, the packet is expanded into individual request information, and the request information is transmitted through the second communication interface unit. A program that functions as a proxy device including a processing unit that causes the subsystem to transmit.