Data communication system and data communication program

Abstract

To provide a data communication system that allows data communication to be carried out easily while ensuring security.SOLUTION: In the data communication system, a first gateway stores port information and address information of a first terminal, sends a name resolution request to a second gateway in response to the name resolution request from the first terminal for a second terminal, and performs name resolution by responding with IP address information of the second gateway on the basis of a name resolution response from the second gateway. The second gateway stores port information and address information of the second terminal, sends a name resolution response with the IP address information for the second gateway in response to the name resolution request from the first gateway, and sends a connection request sent from the first gateway to the second terminal on the basis of the address information of the second terminal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a data communication system for performing data communication via a network. [Background technology]

[0002] Data communications that specify a connection destination using the telephone number of a terminal that subscribes to a telephone service and perform data communications between terminals have been put to practical use. For example, Non-Patent Document 1 provides a data communications service that allows data communications between IP telephone terminals using the telephone number of an IP telephone service. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] NTT West, Basic Service "Data Connect", [Searched on May 22, 2023], Internet<URL:https: / / flets-w.com / opt / hikaridenwa / service / dataconnect / > Summary of the Invention [Problem to be solved by the invention]

[0004] The service described in Non-Patent Document 1 allows secure high-speed data communication by specifying the destination of data communication using the telephone number of an IP telephone service. However, this has the problem that it requires the installation of dedicated equipment on both terminals involved in data communication, and that pre-configuration of the dedicated equipment is required.

[0005] The present invention has been made to solve these problems, and has as its object to provide a data communication system that can easily perform data communication while ensuring security. [Means for solving the problem]

[0006] In order to achieve such an object, a data communication system according to the present invention is a data communication system for performing data communication between a first terminal and a second terminal via a dedicated line between a first gateway device to which a first terminal is connected and a second gateway device to which a second terminal is connected, the first gateway device comprising: a storage unit for storing port information and address information of the first terminal; and a control unit for transmitting a name resolution request of the second terminal to the second gateway device in response to a name resolution request of the second terminal from the first terminal, responding with second IP address information of the second gateway device based on the name resolution response from the second gateway device to perform name resolution, and transmitting a connection request from the first terminal to the second terminal to the second gateway device; the second gateway device comprising: a storage unit for storing port information and address information of the second terminal; and a control unit for transmitting the name resolution response of the second IP address information in response to the name resolution request from the first gateway device, and transmitting the connection request transmitted from the first gateway device to the second terminal based on the address information of the second terminal.

[0007] In order to achieve such an object, a data communication program according to the present invention is a data communication program for causing a computer to function as a data communication system for performing data communication between a first terminal and a second terminal via a dedicated line between a first gateway device to which a first terminal is connected, and a second gateway device to which a second terminal is connected, the data communication program including the steps of: storing, in the first gateway device, a correspondence relationship between a host name of the first terminal and port information and address information; transmitting a name resolution request for the second terminal to the second gateway device in response to a name resolution request for the second terminal from the first terminal; and, based on a name resolution response from the second gateway device, The second gateway device executes a step of performing name resolution in response to the second IP address information of the second gateway device, and transmitting a packet for accessing the second terminal from the first terminal to the second gateway device, and causes the second gateway device to execute a step of storing a correspondence between the host name of the first terminal and port information and address information, and a step of transmitting the name resolution response of the second IP address information based on the host name of the second terminal in response to the name resolution request from the first gateway device, and transmitting the packet transmitted from the first gateway device to the second terminal based on the correspondence between the host name and address information of the second terminal. Effect of the Invention

[0008] According to the present invention, it is possible to provide a data communication system that can easily perform data communication while ensuring security. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a system configuration diagram of a data communication system according to an embodiment of the present invention. [Diagram 2] FIG. 2 shows an example of an operation sequence of the data communication system according to the embodiment of the present invention. [Diagram 3]FIG. 3 shows an example of an operation sequence of the data communication system according to the embodiment of the present invention. [Figure 4] FIG. 4 is an example of an operation flowchart of the gateway (access source) of the data communication system according to the embodiment of the present invention. [Diagram 5] FIG. 5 is an example of an operation flowchart of the gateway (access destination) of the data communication system according to the embodiment of the present invention. [Figure 6] FIG. 6 is an example of a terminal information management table in the data communication system according to the embodiment of the present invention. [Figure 7] FIG. 7 is an example of a terminal information management table in the data communication system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. The present invention can be embodied in various forms and is not limited to the embodiments of the invention described below.

[0011] <Characteristics of the data communication system of the present invention> 1 is a configuration diagram of a data communication system according to an embodiment of the present invention. The data communication system according to the embodiment of the present invention is a data communication system including a gateway device 10 (first gateway device) to which an access source terminal 20 (first terminal) is connected, and a gateway device 30 (second gateway device) to which an access destination terminal 40 (second terminal) is connected.

[0012] The communication network NW includes a dedicated line such as NGN (Next Generation Network) and the Internet. The gateway device 10 is installed on a route that relays an access source terminal 20 connected to a subordinate LAN to the communication network NW, and is configured to route received packets to a dedicated line such as NGN or the Internet.

[0013] In the data communication system of this embodiment, an access source terminal 20 connected to a gateway device 10 performs data communication with an access destination terminal 40 connected to a gateway device 30 via a dedicated line between the gateway device 10 and the gateway device 30. Since the access source terminal 20 performs data communication via the dedicated line between the gateway device 10 and the gateway device 30, there is no risk of packets being intercepted, and data communication with guaranteed security can be performed.

[0014] The dedicated line between the gateway device 10 and the gateway device 30 can be set up, for example, by obtaining the IP addresses of the gateway device 10 and the gateway device 30 using an IP line call between the access source terminal 20 and the access destination terminal 40.

[0015] Since the IP line call between the access source terminal 20 and the access destination terminal 40 includes the IP address information of the gateway device 10 and the gateway device 30, the gateway device 10 can obtain the IP address information of the gateway device 30 by referring to the IP line call, and can access the gateway device 30 to set up a dedicated line connection between the gateway device 10 and the gateway device 30.

[0016] When data communication is performed between the access source terminal 20 and the access destination terminal 40, the gateway device 10 to which the access source terminal 20 is connected needs to perform name resolution of the access destination terminal 40 in order to connect to the gateway device 30 to which the access destination terminal 40 is connected. Also, the gateway device 30 to which the access destination terminal 40 is connected needs to set a routing rule so that a packet transmitted from the access source terminal 20 can be forwarded to the access destination terminal 40.

[0017] In this embodiment, name resolution of the access destination terminal 40 and setting of the routing rule in the gateway device 30 are performed via a dedicated line between the gateway device 10 and the gateway device 30.

[0018] When the access source terminal 20 accesses the access destination terminal 40, the gateway device 10 transmits a name resolution request for the access destination terminal 40 to the gateway device 30, and performs name resolution by responding with the IP address information of the gateway device 30 based on the name resolution response from the gateway device 30. This allows a packet transmitted from the access source terminal 20 to be transmitted to the gateway device 30 to which the access destination terminal 40 is connected.

[0019] In response to a name resolution request from the gateway device 10 for the access destination terminal 40, the gateway device 30 transmits IP address information of the gateway device 30 to perform a name resolution response, and sets a routing rule so that the packet transmitted from the gateway device 10 is transmitted to the access destination terminal 40. This allows the packet transmitted from the access source terminal 20 to be transmitted to the access destination terminal 40.

[0020] In this embodiment, name resolution of the destination terminal 40 is performed via a dedicated line between gateway device 10 and gateway device 30, and routing rules are dynamically set in gateway device 30. Therefore, if the accessing terminal 20 knows the host name of the destination terminal 40, data communication with the destination terminal 40 is possible. This eliminates the need to install dedicated devices in both terminals performing data communication in order to perform data communication, and eliminates the need for pre-settings of dedicated devices for data communication, making it possible to provide a data communication system that allows data communication to be performed easily.

[0021] <Gateway device configuration> The access source gateway device 10 is installed on a path that relays the access source terminal 20 (PC#1-1) connected to the subordinate LAN to the communication network NW. As shown in Fig. 1, the gateway device 10 has a network side I / F 11, a LAN side I / F 12, a storage unit 13, and a control unit 14 as main circuit configurations. The access destination gateway device 30 has a similar configuration to the access source gateway device 10, and relays the access destination terminal 40 (PC#2-1, PC#2-2) connected to the subordinate LAN to the communication network NW.

[0022] <Network side I / F, LAN side I / F> The network side I / F 11 is an I / F for performing data communication with a communication network NW such as the Internet via a communication line L. The LAN side I / F 12 is an I / F for performing data communication with an access source terminal 20 via a LAN.

[0023] The communication network NW provides a dedicated line such as NGN and an Internet connection between the access source terminal 20 and the access destination terminal 40. A SIP server 50 for performing IP line calls between the access source terminal 20 and the access destination terminal 40, and a DNS server 60 for performing name resolution when connecting to the Internet are connected to the communication network NW.

[0024] When connecting to the Internet of the communication network NW, the gateway device 10 requests name resolution from the DNS server 60. In this embodiment, however, the gateway device 10 is configured to perform name resolution because the access source terminal 20 performs data communication with the access destination terminal 40 connected to the gateway device 30 via a dedicated line between the gateway device 10 and the gateway device 30.

[0025] <Storage section> The storage unit 13 is generally composed of a storage unit such as a semiconductor memory. The storage unit 13 stores port information and IP address information of terminals connected to the gateway devices 10 and 30, and a data communication program executed by the control unit 14 of the gateway devices 10 and 30.

[0026] The data communication program executed by the control unit 14 is a processing program that cooperates with the CPU of the control unit 14 to realize various processing units such as management of terminal information such as port information and IP address information, name resolution processing for terminal host names, packet routing processing, and connection processing for connecting dedicated lines between gateways, and causes the computer to function as a data communication system equipped with a gateway device.

[0027] <Configuration of the control unit of the gateway device> The control unit 14 has a CPU and its peripheral circuits, and by having the CPU work in cooperation with the program in the memory unit 13, is provided with a terminal information management unit 14A that manages terminal information such as port information and IP address information of the connected terminal, a name resolution process for the host name of the terminal 14B, a routing processing unit 14C that performs routing process for packets, and a connection processing unit 14D that connects dedicated lines between gateways.

[0028] When a host name is notified from the terminal 20, the terminal information management unit 14A of the control unit 14 of the access source gateway device 10 stores the correspondence relationship between the host name of the terminal 20, the port information, and the IP address.

[0029] When a host name is notified from the terminal 40, the terminal information management unit 14A of the control unit 14 of the access destination gateway device 30 stores the correspondence relationship between the host name of the terminal 40, the port information, and the IP address.

[0030] In response to a name resolution request from the accessing terminal 20 for the access destination terminal 40, the name resolution processing unit 14B of the control unit 14 of the access source gateway device 10 transmits a name resolution request for the terminal 40 to the gateway device 30, and performs name resolution by responding with IP address information of the gateway device 30 based on the name resolution response from the gateway device 30.

[0031] In response to a name resolution request from the gateway device 10, the name resolution processing unit 14B of the control unit 14 of the destination gateway device 30 transmits a name resolution response of the IP address information of the gateway device 30 based on the port information of the connected terminal.

[0032] The routing processing unit 14C of the control unit 14 of the access source gateway device 10 sets the source port of a packet for accessing the terminal 40 from the terminal 20 in the port information of the terminal 20, and transmits the packet to the gateway device 30.

[0033] The routing processing unit 14C of the control unit 14 of the gateway device 30 to be accessed sets the destination IP address of the packet sent from the gateway device 10, in which the port information of the terminal 20 is set as the source port, to the IP address information of the terminal 40, and transmits the packet to the terminal 40.

[0034] The connection processing unit 14D of the control unit 14 of the accessing gateway device 10 utilizes IP line communication to obtain the IP addresses of the gateway device 10 and the gateway device 30, thereby connecting a dedicated line between the gateway device 10 and the gateway device 30.

[0035] The connection processing unit 14D of the control unit 14 of the accessed gateway device 30 uses IP line communication to obtain the IP addresses of the gateway device 10 and the gateway device 30, thereby connecting a dedicated line between the gateway device 10 and the gateway device 30.

[0036] <Address resolution process sequence> The operation sequence of the data communication system will be described with reference to Figures 2 and 3. Figure 2 shows an example of the operation sequence of the data communication system according to the embodiment of the present invention. Figure 2 shows the operation sequence from when a terminal is connected to a gateway device to when a dedicated line between the gateway devices is connected.

[0037] The access source terminal 20 (PC#1-1) connects to the gateway device 10 and notifies the gateway device 10 of its host name (steps 100, 101). The gateway device 10 is assigned an IP address (first IP address information) (10.10.10.10).

[0038] When the gateway device 10 receives the host name from the terminal 20, it stores the correspondence between the host name and the port information and IP address information of the terminal 20 (step 102). The port information (49150) and the IP address information (172.16.1.10) are assigned to the terminal 20 (PC#1-1).

[0039] The destination terminal 40 (PC#2-1, PC#2-2) connects to the gateway device 30 and notifies the gateway device 30 of the host name (steps 200-203). The gateway device 30 is assigned an IP address (second IP address information) (20.20.20.20).

[0040] When the gateway device 30 receives the host name from the terminal 40, it stores the correspondence between the host name and the port information and IP address information of the terminal 40 (step 204). The port information (49152) and the IP address information (192.168.2.11) are assigned to the terminal 40 (PC#2-1). The port information (49153) and the IP address information (192.168.2.12) are assigned to the terminal 40 (PC#2-2).

[0041] Prior to starting data communication, the access source gateway device 10 and the access destination gateway device 30 establish an IP line call between the access source terminal 20 and the access destination terminal 40, and connect a dedicated line between the gateway device 10 and the gateway device 30 using the IP line call (steps 301, 301).

[0042] 6 and 7 are configuration examples of the terminal information management table showing the correspondence between the host name and the port information and IP address information of the terminal. The gateway device 10 and the gateway device 30 can perform name resolution of the connected terminal by referring to the terminal information management table, and can transmit the received packet to the terminal connected to the subordinate LAN.

[0043] Fig. 3 shows an example of an operation sequence of the data communication system according to the embodiment of the present invention, which is from the start of access from the access source terminal to the start of data communication.

[0044] In order to access the destination terminal 40 (PC #2-1), the access source terminal 20 (PC #1-1) transmits a name resolution request for the terminal 40 (PC #2-1) to the gateway device 10 (steps 400, 401). The gateway device 10 transmits a name resolution request for the terminal 40 (PC #2-1) to the gateway device 30 (step 402).

[0045] When the gateway device 30 receives a name resolution request for the terminal 40 (PC#2-1) from the gateway device 10, it transmits a name resolution response for the IP address information (20.20.20.20) of the gateway device 30 based on the terminal information management table (step 403). The gateway device 30 goes into a state of waiting for a connection from the terminal 20 (PC#1-1, source port: 49150) to the terminal 40 (PC#2-1) (step 405).

[0046] When the gateway device 10 receives the name resolution response for the IP address information (20.20.20.20) of the gateway device 30, it transmits the name resolution response for the IP address information of the gateway device 30 to the terminal 20 (PC#1-1) (step 404).

[0047] Terminal 20 (PC #1-1) uses the received IP address information of gateway device 30 to send a connection request (WEB access (destination PT: 80)) to terminal 40 (PC #2-1), and gateway device 10 sends an IP packet (source PT: 49150, destination PT: 80, source IP address: 10.10.10.10, destination IP address: 20.20.20.20) with the source port set to the port information of terminal 20 to gateway device 30 (steps 500, 501).

[0048] In step 405, gateway device 30 is in a state of waiting for a connection from terminal 20 (PC #1-1, source port: 49150) to terminal 40 (PC #2-1), so based on the terminal information management table, it converts the destination IP address (20.20.20.20) of the received IP packet of the connection request into the IP address (192.168.2.11) of terminal 40 (PC #2-1) and sends it to terminal 40 (PC #2-1) (steps 502, 503).

[0049] When terminal 40 (PC#2-1) responds, a routing rule is set so that a connection request IP packet with the source port set to the port information (49150) of terminal 20 is sent to the IP address (192.168.2.11) of terminal 40 (PC#2-1). This enables data communication between terminal 20 (PC#1-1) and terminal 40 (PC#2-1) (steps 504-600).

[0050] <Gateway (access source) operation flowchart> FIG. 4 is an example of an operation flowchart of the gateway (access source) of the data communication system according to the embodiment of the present invention.

[0051] When the gateway device 10 receives a host name from the terminal 20, the gateway device 10 stores the corresponding relationship between the host name, port information, and IP address information of the terminal 20 (S1-1, S1-2).

[0052] Prior to the start of data communication, the access source gateway device 10 and the gateway device 30 connect a dedicated line between the gateway device 10 and the gateway device 30 (S1-3).

[0053] When the gateway device 10 receives a name resolution request for the destination terminal 40 (PC #2-1) from the source terminal 20 (PC #1-1), it transmits the name resolution request for the terminal 40 (PC #2-1) to the gateway device 30 (S1-4, S1-5).

[0054] When the gateway device 10 receives the name resolution response of the IP address information of the gateway device 30 from the gateway device 30, it transmits the IP address information of the gateway device 30 to the terminal 20 (PC#1-1) (S1-6, S1-7).

[0055] When the gateway device 10 receives a WEB access (destination PT: 80) from the terminal 20 (PC#1-1), it transmits an IP packet (source PT: 49150, destination PT: 80, source IP address: 10.10.10.10, destination IP address: 20.20.20.20) to the gateway device 30 (S1-8, S1-9).

[0056] <Gateway (access destination) operation flowchart> FIG. 5 is an example of an operation flowchart of the gateway (access destination) of the data communication system according to the embodiment of the present invention.

[0057] When the gateway device 30 receives the host name from the terminal 40, it stores the correspondence relationship between the host name, port information, and IP address information of the terminal 40 (S2-1, S2-2, S2-3).

[0058] Prior to the start of data communication, the access source gateway device 10 and the gateway device 30 connect a dedicated line between the gateway device 10 and the gateway device 30 (S2-3).

[0059] When the gateway device 30 receives a name resolution request for the terminal 40 (PC#2-1) from the gateway device 10, it transmits a name resolution response for the IP address information (20.20.20.20) of the gateway device 30 based on the terminal information management table (S2-4, S2-5). The gateway device 30 goes into a state of waiting for a connection from the terminal 20 (PC#1-1, source port: 49150) to the terminal 40 (PC#2-1) (S2-6).

[0060] The gateway device 30 receives the connection request IP packet (source PT: 49150, destination PT: 80, source IP address: 10.10.10.10, destination IP address: 20.20.20.20) from the gateway device 10 (S2-7).

[0061] Since gateway device 30 is in a state of waiting for a connection from terminal 20 (PC #1-1, source port: 49150) to terminal 40 (PC #2-1), based on the terminal information management table, it converts the destination IP address (20.20.20.20) of the received IP packet of the connection request to the IP address of PC #2-1 (192.168.2.11) and sends it to PC #2-1 (S2-8, S2-9).

[0062] In the gateway device 30, a routing rule is set so that a connection request with a source PT of "49150" is sent to the IP address of PC#2-1, enabling data communication between PC#1-1 and PC#2-1 (S2-10). <Effects of this embodiment>

[0063] In this embodiment, name resolution of the destination terminal 40 is performed via a dedicated line between gateway device 10 and gateway device 30, and routing rules are dynamically set in gateway device 30. Therefore, if the accessing terminal 20 knows the host name of the destination terminal 40, data communication with the destination terminal 40 is possible. This eliminates the need to install dedicated devices in both terminals performing data communication in order to perform data communication, and eliminates the need for pre-settings of dedicated devices for data communication, making it possible to provide a data communication system that allows data communication to be performed easily.

[0064] <Extended embodiment> Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above embodiment. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. [Explanation of symbols]

[0065] 10...gateway device (access source), 11...network side I / F, 12...LAN side I / F, 13...memory unit, 14...control unit, 20...terminal (access source), 30...gateway device (access destination), 40...terminal (access destination), 50...SIP server, 60...DNS server, L...communication line, NW...communication network.

Claims

1. A data communication system for performing data communication between a first gateway device to which a first terminal is connected and a second gateway device to which a second terminal is connected via a dedicated line between the first gateway device and the second gateway device, the first gateway device, a storage unit that stores port information and address information of the first terminal; a control unit that transmits a name resolution request for the second terminal to the second gateway device in response to a name resolution request for the second terminal from the first terminal, and performs name resolution by responding with second IP address information of the second gateway device based on a name resolution response from the second gateway device, and transmits a connection request from the first terminal to the second gateway device, The second gateway device a storage unit that stores port information and address information of the second terminal; a control unit that transmits the name resolution response of the second IP address information in response to the name resolution request from the first gateway device, and transmits the connection request transmitted from the first gateway device to the second terminal based on address information of the second terminal. Data communication system.

2. A data communication program for causing a computer to function as a data communication system for performing data communication between a first gateway device to which a first terminal is connected and a second gateway device to which a second terminal is connected via a dedicated line between the first gateway device and a second gateway device, the program comprising: The first gateway device storing a correspondence relationship between the host name of the first terminal and port information and address information; transmitting a name resolution request for the second terminal to the second gateway device in response to a name resolution request for the second terminal from the first terminal, and performing name resolution by responding with second IP address information of the second gateway device based on a name resolution response from the second gateway device, and transmitting a packet for accessing the second terminal from the first terminal to the second gateway device; Execute The second gateway device storing a correspondence relationship between the host name of the first terminal and port information and address information; transmitting the name resolution response of the second IP address information based on the host name of the second terminal in response to the name resolution request from the first gateway device, and transmitting the packet transmitted from the first gateway device to the second terminal based on a correspondence relationship between the host name and address information of the second terminal; Run Data communication program.

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