JPH11215195A - System and method for inter-network connection and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for inter-network connection system which can reduce the load when a repeater is connected. SOLUTION: When power supply is made, an acting server 12 first establishes the connection with a repeater 3. Then the server 12 establishes the connection with an acting client 22 through the repeater 3. The server 12 maintains the connection with the client 22 thus established through the repeater 3. A client 11 first establishes the connection with the acting server 12 when the connection with a server 21 becomes necessary. Then the client 11 establishes the connection with the server 21 through the acting server 12, repeater 3, and acting client 22 among which connection is already established. The client 11 transmits and receives necessary data after the connection with the server 21 is established.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-network connection system, an inter-network connection method, and a recording medium capable of reducing a load when connecting a relay device.

[0002]

2. Description of the Related Art An inter-network connection system connects a plurality of networks to each other via a relay device, and enables clients and servers in the networks to be connected to other networks. With such an inter-network connection system, a client can communicate with an arbitrary server in another network via a relay device and acquire data or the like that does not exist in the network to which the client belongs.

In recent years, due to an increase in demand and the like, congestion of communication data and a decrease in data transfer speed have come to be regarded as problems in such communication connections between networks. As an inter-network connection system that has improved such points, Proxy installed on the client side network
Japanese Patent Application Laid-Open No. 09-186723 discloses a technique in which a server (proxy server) performs flow control and congestion control between networks to increase the data transfer speed between networks.

Japanese Patent Application Laid-Open No. 08-202726 discloses a technique for shortening the data transfer time in the entire network by dynamically changing the arrangement of relay servers (proxy servers) based on the data transfer time. Is disclosed.

[0005]

However, Japanese Patent Application Laid-Open No.
The inter-network connection system disclosed in Japanese Patent Application Laid-Open No. 186723 and Japanese Patent Application Laid-Open No. 08-202726 discloses that when a client needs to connect to a server on another network, the client first connects to a relay device and Establish a communication connection with a server on another network via the device. That is, when a client starts a connection with a server, the network connection system first connects the client and the relay device, then connects the client and the server via the relay device, and connects the client and the server. Communication with Therefore, the client
Each time a connection to a server on another network is made, overhead time is required, and it takes some time until a communication connection with the server is established.

Further, when a plurality of clients simultaneously connect to a plurality of servers on another network, the relay device must handle connections between the plurality of clients and the server at the same time and further perform a process of establishing a communication connection between them. Therefore, there is a problem that the processing capacity is reduced to some extent.

[0007] The present invention has been made in view of the above situation, and has as its object to provide an inter-network connection system and an inter-network connection method that can reduce the load on the relay device.

[0008]

In order to achieve the above object, an inter-network connection system according to a first aspect of the present invention comprises a first computer connected to a first network and a second computer. The connected second computer is an inter-network connection system that performs communication connection via a relay device that relays a connection between the first network and the second network, wherein the first network is , A third computer, the third computer pre-established a communication connection with the second computer via the repeater, maintaining the established communication connection substantially permanently,
The first computer makes a communication connection with the second computer via the third computer.

According to the present invention, the first computer has the third computer
A communication connection with the second computer is made via the computer. As a result, it is necessary for the relay device to only relay data transmitted and received between the third computer and the second computer, and to make a new communication connection between the first network and the second network. Therefore, the processing load can be reduced.

The third computer further includes a storage unit for storing communication addresses of the repeater and the second computer, and communicates with the repeater using the communication address stored in the storage unit. A connection may be established, a communication connection with the second computer may be established in advance via the established connection with the relay device, and the established communication connection may be maintained substantially permanently.

To achieve the above object, an inter-network connection system according to a second aspect of the present invention comprises a first computer connected to a first network and a second computer connected to a second network. A computer is an inter-network connection system that performs a communication connection via a relay that relays a connection between the first network and the second network, wherein the first network includes a third computer. Furthermore, the second network further includes a fourth computer, wherein the third computer previously establishes a communication connection with the fourth computer via the relay device, and establishes the established communication connection. Maintained substantially constantly, wherein the first computer makes a communication connection with the fourth computer via the third computer.

According to the present invention, the first computer is provided with the third computer.
A communication connection with the fourth computer is made via the computer. As a result, the relay device only needs to relay data transmitted and received between the third computer and the fourth computer, and needs to make a new communication connection between the first network and the second network. Because there is no processing load, the processing load can be reduced.

The third computer further includes a storage unit for storing communication addresses of the repeater and the fourth computer, and communicates with the repeater using the communication addresses stored in the storage unit. A connection may be established, a communication connection with the fourth computer may be established in advance via the established connection with the relay device, and the established communication connection may be maintained substantially permanently.

To achieve the above object, a method for connecting networks according to a third aspect of the present invention comprises a client and a proxy server connected to a first network and a server and a proxy server connected to a second network. An inter-network connection method in which a client makes a communication connection via a relay that relays a connection between the first network and the second network, wherein the client establishes a communication connection between the proxy server and the relay. Performing a first connection step and performing a second communication connection between the relay device and the proxy client.
The connection step, the communication connection between the proxy server and the proxy client via the repeater connected by the first step and the second step is established in advance,
A holding step of holding the established communication connection substantially permanently; and a communication connection between the client and the server via the connection of the proxy server, the relay device, and the proxy client held by the holding step. Performing a third connection step.

According to the present invention, the third connection step includes the step of holding the client and the server via the connection between the proxy server and the proxy client via the relay machine whose communication connection is substantially permanently held by the holding step. Communication connection. As a result, the relay device only relays data transmitted and received between the proxy server and the proxy client, and does not need to make a new communication connection between the first network and the second network. The processing load can be reduced.

To achieve the above object, a recording medium according to a fourth aspect of the present invention comprises a client and a proxy server connected to a first network, and a server and a proxy client connected to a second network. Is a computer-readable recording medium for recording a program for making a communication connection via a relay device that relays a connection between the first network and the second network, wherein the proxy server and the relay device A first connection step of making a communication connection of the second, a second connection step of making a communication connection between the relay device and the proxy client, and the relay device connected by the first step and the second step Holding a communication connection between the proxy server and the proxy client via the communication server in advance, and holding the established communication connection permanently. And a third connection step of establishing a communication connection between the client and the server via the connection between the proxy server, the relay device, and the proxy client held by the holding step. It is characterized by.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A network connection system according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating an example of an inter-network connection system according to an embodiment of the present invention. These inter-network connection systems include a first network 1, a second network 2, and a relay device 3.

The first network 1 comprises at least a client 11 and a proxy server 12.

The client 11 is composed of a workstation or the like, and transmits data for requesting connection and disconnection with the server 21 of the second network 2, for example, to the proxy server 12 in accordance with a user access request.
The client 11 communicates with the server 2 via the proxy server 12.
1 and establishes a communication connection with the server 21 to transmit and receive necessary data to and from the server 21.

The proxy server 12 is composed of a workstation or the like, and stores the addresses of the relay device 3 and the proxy client 22 of the second network 2 in a storage unit (not shown) in advance. The address stored in the storage unit includes the number and name of the connection device, an IP address in the TCP / IP protocol, and the like.

The proxy server 12 connects to the relay device 3 and the proxy client 22 according to the addresses of the relay device 3 and the proxy client 22 stored in the storage unit at the time of initialization such as when the power is turned on. That is, the proxy server 12
The connection request data is transmitted to the address destination of the relay device 3, and the connection with the relay device 3 is established by receiving the connection response data from the relay device 3. The proxy server 12 transmits the connection request data to the address destination of the proxy client 22 via the established connection with the relay device 3 and receives the connection response data from the proxy client 22, whereby the proxy client 22 is established. The proxy server 12 maintains the communication connection with the proxy client 22 via the relay device 3 while the power of the proxy server 12 is turned on, that is, substantially constantly.

When the client 11 needs to connect and disconnect with the server 21, the proxy server 12 receives data requesting connection and disconnection with the server 21 sent from the client 11, and relays the received data. The information is transmitted to the proxy client 22 via the device 3. Proxy server 1
2 establishes a communication connection between the client 11 and the server 21, and relays transmission / reception data exchanged between the client 11 and the server 21.

The second network 2 comprises at least a server 21 and a proxy client 22.

The server 21 is composed of a workstation or the like. When the client 11 needs to connect and disconnect with the server 21, the server 21 sends data requesting connection and disconnection from the client 11 via the proxy client 22. Receive. The server 21 establishes and disconnects a communication connection with the client 11 in response to the data requesting connection and disconnection. The server 21 establishes a communication connection with the client 11 via the proxy client 22, and transmits and receives necessary data to and from the client 11.

The proxy client 22 comprises a workstation or the like, and establishes a communication connection with the proxy server 12 via the relay device 3 when the proxy server 12 is initialized.
The proxy client 22 maintains the communication connection with the proxy server 12 via the relay device 3 while the power of the proxy server 12 is turned on, that is, substantially constantly.

The proxy client 22 is a client 1
When the client 1 needs to connect and disconnect from the server 21, the client 1 receives data requesting connection and disconnection from the client 11 from the client 11 via the relay device 3 and transmits the received data to the server 21. I do. The proxy client 22 establishes a communication connection between the client 11 and the server 21 and relays transmission / reception data exchanged between the client 11 and the server 21.

The relay device 3 is composed of a router, two routers connected by a line, an exchange, a switching network, etc., and transmits and receives data between the proxy server 12 and the proxy client 22 when the proxy server 12 is initialized. Relay and proxy server 1
2 and a proxy client 22 are established.
The relay device 3 includes a proxy server 12 and a proxy client 22
, And relays transmission / reception data exchanged between the proxy server 12 and the proxy client 22.

A connection operation in the network connection system according to the first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 2, the client 11, the proxy server 12, and the relay device 3 have addresses “
1.1 "," 1.2 ", and" 1.3 "are assigned to the server 21 and the proxy client 2.
2. It is assumed that addresses "2.1", "2.2", and "2.3" are assigned to the second network side of the relay device 3, respectively.

First, a description will be given of a process for establishing a connection between the proxy server 12 and the proxy client 22 which is performed when the proxy server 12 is initialized at power-on or the like.

As shown in FIG. 3A, the proxy server 12
Is initialized, the proxy server 12 sends the data requesting connection to the address "1.3" (relay device 3) to the address "2.2" (proxy client 22) stored in advance. Transmit (step A1).

The relay device 3 receives the data requesting connection with the address “2.2” (the proxy client 22) sent from the proxy server 12, and transfers the received data to the address “2.2” (the proxy client 22). 22) (Step A2).

The proxy client 22 receives the connection request data transmitted from the proxy server 12 via the relay device 3, performs a predetermined check on the received data, and then requests the connection with the proxy server 12. Generate data that responds to. That is, the proxy client 22 receives the address “
1.2 "(proxy server 12) is checked whether connection is possible or not, and if connection is possible, address" 1.
The proxy client 22 generates data in response to the connection request with the proxy server 12. The proxy client 22 transfers the generated data in response to the connection request with the proxy server 12 to the relay source address "2.3" (relay). The data is transmitted to the device 3) (step A3).

The relay device 3 receives the data responding to the connection request with the address “1.2” (the proxy server 12) sent from the proxy client 22, and transfers the received data to the address “1.2” (the proxy It transmits to the server 12) (step A4).

The proxy server 12 establishes a communication connection with the proxy client 22 by receiving data responding to the connection request with the proxy server 12 transmitted from the proxy client 22 via the relay device 3. Proxy server 1
2. The relay device 3 and the proxy client 22 substantially constantly maintain the communication connection thus established. As a result, the relay device 3 only needs to relay data transmitted and received between the proxy server 12 and the proxy client 22, and need to make a new communication connection between the first network and the second network. Therefore, the processing load can be reduced.

Next, a description will be given of a connection establishing process performed when the client 11 needs a communication connection with the server 21. This process is performed at a normal time after the communication connection between the proxy server 12 and the proxy client 22 is established.

As shown in FIG. 3B, the client 1
When the connection with the server 21 is started, the proxy server 1
Then, the data requesting connection with the server 2 is transmitted to the address "1.2" (the proxy server 12) (step A5).

The proxy server 12 receives the data requesting the connection sent from the client 11, performs a predetermined check on the received data, and then generates data responding to the connection request, and generates the data "1. 1 "(client 11) (step A6).

The client 11 receives the data responding to the connection request from the proxy server 12, establishes a communication connection with the proxy server 12, and transmits the address information (server information) of the server 21 via the proxy server 12. To the address "1.2" (the proxy server 12) (step B1).

The proxy server 12 receives the address information (server information) of the server 21 from the client 11,
The received address information (server information) is converted to the address “2.2” for which a connection has already been established via the relay device 3.
(Step B)
2).

The proxy client 22 is a proxy server 12
Upon receiving the address information (server information) of the server 21 from the server, the server generates data for requesting connection with the server 21 from the received address information and transmits the data to the address "2.1" (server 21) (step A7).

The server 21 receives the data requesting the connection sent from the proxy client 22, performs a predetermined check on the received data, and generates data responding to the connection request. 2 "(the proxy client 22) (step A8).

Upon receiving the data responding to the connection request from the server 21, the proxy client 22 generates connection success information for the client 11, and transmits it to the address “1.2” (the proxy server 12) via the relay device 3. (Step B3).

The proxy server 12 receives the connection success information for the client 11 from the proxy client 22 via the relay device 3 and sends the received connection success information to the address “
1.1 "(client 11) (step B
4).

The client 11 receives the connection success information sent from the proxy server 12, and
1 is established with the communication connection. As a result, the client 11 can transmit and receive actual data to and from the server 21. For example, the client 11 transmits request data for requesting the image data held by the server 21 to the address “1.2” (the proxy server 12) (step B5). The proxy server 12 transmits the received request data to the address “2.2” (proxy client 22) via the relay device 3 (Step B6). The proxy client 22 transmits the received request data to the address “2.1” (server 21) (Step B7).

The server 21 receives the request data from the client 11, reads out the image data requested by the received request data from a storage device (not shown) or the like, and stores the image data for the client 11 at the address "2.2".
(Step B)
8). The proxy client 22 transfers the received image data to the address “1.2” (the proxy server 1) via the relay device 3.
2) (Step B9). The proxy server 12
The received image data is transmitted to the address "1.1" (client 11) (step B10). As a result, the client 11 can receive the image data requested from the server 21.

Next, the connection disconnection processing performed when the client 11 needs to disconnect from the server 21 will be described. This process is performed after a communication connection between the client 11 and the server 21 is established.

As shown in FIG. 3C, the client 1
When the connection with the server 21 is started, the data requesting the disconnection with the proxy server 12 is transmitted to the address “1.
2 "(the proxy server 12) (step A9).

The proxy server 12 receives the data requesting the disconnection sent from the client 11, performs a predetermined check on the received data, generates data responding to the disconnection request, and generates an address "1". .. 1 ”(client 11) (step A10).

The client 11 receives data responding to the disconnection request from the proxy server 12 and disconnects the communication connection with the proxy server 12.

The proxy server 12 transmits data responding to the disconnection request to the client 11, generates disconnection information indicating that the connection with the client 11 has been disconnected, and outputs the address “2. 2 "(the proxy client 22) (step B11).

The proxy client 22 is connected to the proxy server 12
When the disconnection information is received from the server, data for requesting disconnection from the server 21 is generated from the received disconnection information and transmitted to the address "2.1" (the server 21) (step A1).
1).

The server 21 receives the data for requesting the disconnection sent from the proxy client 22, performs a predetermined check on the received data, generates data responding to the disconnection request, and generates an address "2". .2 "(the proxy client 22) (step A12).

When the proxy client 22 receives the data responding to the disconnection request from the server 21, the proxy client 1
2 is generated and transmitted to the address “1.2” (the proxy server 12) via the relay device 3 (step B12).

The communication connection between the server 21 and the proxy client 22 is disconnected when the proxy server 12 receives the disconnection success information of the proxy client 22 via the relay device 3.

The connection operation involved in actual data transmission / reception in the network connection system according to the first embodiment of the present invention will be described below with reference to FIG. It is assumed that the communication connection between the proxy server 12 and the proxy client 22 has been established in advance.

First, when the user operating the client 11 accesses the document data 1 stored in another server, the client 11 acquires the storage destination address of the document data 1 and the storage destination address is changed to the first storage address. Is determined to be within the network. When the client 11 acquires that the storage address of the document data 1 is the address “2.1” (server 21) of the second network,
Data requesting connection with the proxy server 12 is transmitted to the proxy server 12 (step S1).

The proxy server 12 receives the connection request data from the client 11, performs a predetermined check, and then generates data responding to the connection request, and transmits the data to the client 11 (step S2).

The client 11 receives the data responding to the connection request from the proxy server 12, establishes a communication connection with the proxy server 12, and transmits address information (server information) of the server 21 to the proxy server 12. (Step S3).

The proxy server 12 receives the address information (server information) from the client 11, and transmits the received address information (server information) to the proxy client 22 via the relay device 3 (step S4).

The proxy client 22 is the proxy server 12
When the server receives address information (server information) of the server 21 from the server, it generates data for requesting connection with the server 21 from the received address information and transmits the data to the server 21 (step S5).

The server 21 receives the data requesting the connection sent from the proxy client 22, performs a predetermined check on the received data, generates data in response to the connection request, and sends the data to the proxy client 22. It transmits (step S6).

When the proxy client 22 receives the data responding to the connection request from the server 21, it generates connection success information for the client 11 from the received data and transmits it to the proxy server 12 via the relay device 3 (step S7). .

The proxy server 12 receives the connection success information from the proxy client 22 via the relay device 3, and transmits the received connection success information to the client 11 (step S8).

The client 11 receives the connection success information sent from the proxy server 12, establishes a connection with the server 21, and transmits request data for requesting the document data 1 to the server 21 to the proxy server 12 (step). S9).

The proxy server 12 transmits the received request data to the proxy client 22 via the relay device 3 (Step S10).

The proxy client 22 transmits the received request data to the server 21 (Step S11).

The server 21 receives the data requesting the document data 1 from the client 11, reads out the document data 1 stored in an auxiliary storage device (not shown) of the server 21, and sends the document data 1 to the client 11. Is transmitted to the proxy client 22 (step S12).

The proxy client 22 transmits the received document data 1 to the proxy server 12 via the relay device 3 (Step S13).

The proxy server 12 receives the received document data 1
Is transmitted to the client 11 (step S14). As a result, the client 11 can acquire the document data 1 requested by the server 21.

Next, the client 1 is operated by the user.
When the client 1 terminates the access to the document data 1, the client 11 starts disconnecting the communication connection with the server 21. When the disconnection of the communication connection with the server 21 is started, the client 11 transmits data requesting the disconnection of the connection with the proxy server 12 to the proxy server 12 (step S1).
5).

The proxy server 12 receives the data requesting the disconnection, performs a predetermined check on the received data, generates data responding to the disconnection request, and transmits the data to the client 11 (step S16). .

The client 11 disconnects the communication connection with the proxy server 12 by receiving data responding to the disconnection request from the proxy server 12. Proxy server 12
Transmits disconnection request data to the client 11, generates disconnection information indicating that the connection with the client 11 has been disconnected, and transmits the generated disconnection information to the proxy client 22 via the relay device 3. (Step S17).

The proxy client 22 is the proxy server 12
Upon receiving the disconnection information from the server, the server generates data requesting disconnection from the server 21 from the received disconnection information and transmits the data to the server 21 (step S18).

The server 21 receives the data for requesting the disconnection sent from the proxy client 22, performs a predetermined check on the received data, and generates data in response to the disconnection request. (Step S19).

When the proxy client 22 receives the data responding to the disconnection request from the server 21, the proxy client 1
Then, it generates disconnection success information for 2 and transmits it to the proxy server 12 via the relay device 3 (step S20).

The communication connection proxy between the server 21 and the proxy client 22 is disconnected when the server 12 receives the disconnection success information from the proxy client 22 via the relay device 3.

As described above, even if the connection between the client 11 and the proxy server 12 and the connection between the server 21 and the proxy client 22 are disconnected, the proxy server 12, the relay device 3 and the proxy client 22 are established. Keep holding the communication connection. As a result, the relay device 3 only needs to relay data transmitted and received between the proxy server 12 and the proxy client 22, and need to make a new communication connection between the first network and the second network. Therefore, the processing load can be reduced.

In the first embodiment, an inter-network connection is made between a network composed of a single client 11 and a proxy server 12 and a network composed of a single server 21 and a proxy client 22. The configuration of the network is arbitrary. For example, an inter-network connection between a network including the proxy server 12 and a plurality of clients and a network including the proxy client 22 and a plurality of servers may be used.

In this case, even when a plurality of clients simultaneously connect to a plurality of servers, respectively, the relay device 3
Merely connects the proxy server 12 and the proxy client 22, the load on the relay device can be reduced, and the communication performance between the client and the server can be improved.

In the first embodiment, the client 11
And a first network comprising the proxy server 12 and a second network comprising the server 21 and the proxy client 22, but the second network comprises the server 21 having no proxy client 22. May be done. Hereinafter, a description will be given of an inter-network connection system according to a second embodiment of the present invention, which connects a first network including a client 11 and a proxy server 12 and a second network including a server 21.

FIG. 5 is a block diagram showing an example of the network connection system according to the second embodiment of the present invention. These network connection systems include a first network 1 composed of at least a client 11 and a proxy server 12, and at least a server 2
1 and a second network 2 composed of
It is composed of

The network connection system shown in FIG. 5 is different from the network connection system according to the first embodiment of the present invention shown in FIG. 1 in that the proxy client 22 of the second network is omitted. . Other configurations are the same as those in FIG.

Since the proxy client 22 is omitted from the server 21 of the second network, the proxy server 12
At the time of initialization, a communication connection with the proxy server 12 is established via the relay device 3. The server 21 maintains the communication connection with the proxy server 12 via the relay device 3 during the period when the power of the proxy server 12 is turned on, that is, substantially constantly.

The connection operation in the network connection system according to the second embodiment of the present invention will be described below with reference to FIG.

First, the connection establishment process between the proxy server 12 and the server 21 which is performed when the proxy server 12 is initialized at the time of power-on or the like will be described.

As shown in FIG. 6A, the proxy server 12
Is initialized, the proxy server 12 transmits data requesting connection with the server 21 to the relay device 3 (step C1).

The relay apparatus 3 receives the data requesting connection with the server 21 sent from the proxy server 12, and transmits the received data to the server 21 (step C2).

The server 21 receives the data requesting the connection, performs a predetermined check on the received data, generates data responding to the connection request with the proxy server 12, and transmits the data to the relay device 3. (Step C3).

The relay device 3 receives the data responding to the connection request, and transmits the received data to the proxy server 12 (step C4).

The proxy server 12 establishes a communication connection with the server 21 by receiving data responding to a connection request from the server 21 via the relay device 3. The proxy server 12, the relay device 3, and the server 21 maintain the communication connection thus established during the period when the power of the proxy server 12 is turned on, that is, substantially constantly. As a result, the relay device 3 only relays data transmitted and received between the proxy server 12 and the server 21, and does not need to make a new communication connection between the first network and the second network. Therefore, the processing load can be reduced.

Next, the connection establishing process performed when the client 11 needs a communication connection with the server 21 will be described. This process is performed at a normal time after the communication connection between the proxy server 12 and the server 21 is established.

As shown in FIG. 6B, the client 1
When the connection with the server 21 is started, the server 1 first transmits data requesting a connection with the proxy server 12 to the proxy server 12 (step C5).

The proxy server 12 receives the data requesting the connection, performs a predetermined check on the received data, generates data in response to the connection request, and transmits the data to the client 11 (step C6).

The client 11 receives the data responding to the connection request, establishes a communication connection with the server 21, and transmits address information (server information) of the server 21 to the proxy server 12 (step D1).

By establishing a communication connection with the server 21, the client 11 can transmit and receive actual data to and from the server 21. For example, client 11
Transmits the request data requesting the image data held by the server 21 to the proxy server 12 (step D).
2). The proxy server 12 transmits the received request data to the server 21 via the relay device 3 (Step D3).

Upon receiving the request data from the client 11, the server 21 reads out the image data requested by the received request data from a storage device (not shown) or the like, and transmits the image data for the client 11 via the relay device 3 to the proxy server. 12 (step D4). The proxy server 12 transmits the received image data to the client 11 (Step D5). As a result, client 1
1 can receive the image data requested from the server 21.

Next, the connection disconnection processing performed when the client 11 needs to disconnect from the server 21 will be described. This process is performed after a communication connection between the client 11 and the server 21 is established.

As shown in FIG. 6C, the client 1
When the connection with the server 21 is started, the server 1 transmits data requesting the connection with the proxy server 12 to the proxy server 12.
(Step C7).

The proxy server 12 receives the data requesting the disconnection, performs a predetermined check on the received data, generates data responding to the disconnection request, and transmits the data to the client 11 (step C8). .

The client 11 disconnects the communication connection with the proxy server 12 by receiving data responding to the disconnection request from the proxy server 12, and also disconnects the communication connection with the server 21.

The connection operation involved in actual data transmission / reception in the network connection system according to the second embodiment of the present invention will be described below with reference to FIG. It is assumed that the communication connection between the proxy server 12 and the server 21 has been established in advance.

First, when the user operating the client 11 accesses the document data 2 stored in another server, the client 11 obtains the storage destination of the document data 2 and the storage destination is the first network. It is determined whether it is within. Upon acquiring that the storage destination of the document data 1 is the server 21 of the second network, the client 11 transmits data requesting connection with the proxy server 12 to the proxy server 12 (step T1).

The proxy server 12 receives the connection request data, performs a predetermined check, generates data in response to the connection request, and transmits the data to the client 11 (step T2).

The client 11 receives the data responding to the connection request, establishes a communication connection with the server 21, and transmits address information (server information) of the server 21 to the proxy server 12 (step T3).

When the client 11 establishes a communication connection with the server 21, the client 11 transmits request data for requesting the document data 2 to the server 21 to the proxy server 12 (step T4).

The proxy server 12 transmits the received request data to the server 21 via the relay device 3 (step T).
5).

The server 21 receives the request data, reads out the document data 2 stored in the storage device (not shown) of the server 21, and transmits the document data 2 to the client 11 to the proxy server 12 via the relay device 3. (Step T6).

The proxy server 12 receives the document data 2
Is transmitted to the client 11 (step T7). As a result, the client 11 can acquire the document data 2 requested from the server 21.

Next, the client 1 is operated by the user.
When 1 terminates the access to the document data 2, the client 11 starts disconnecting the communication connection with the server 21. When disconnection of the communication connection with the server 21 is started, the client 11 transmits data requesting disconnection of the connection with the proxy server 12 to the proxy server 12 (step T).
8).

The proxy server 12 receives the data requesting the disconnection, performs a predetermined check on the received data, generates data responding to the disconnection request, and transmits the data to the client 11 (step T9). .

The client 11 disconnects the communication connection with the server 21 by receiving data responding to the disconnection request.

As described above, even after the connection between the client 11 and the proxy server 12 is disconnected, the proxy server 12
The relay device 3 and the server 21 continue to maintain the established communication connection. As a result, the relay device 3
Only the relay of data transmitted and received between the network and the server 21 is performed, and there is no need to make a new communication connection between the first network and the second network, so that the processing load can be reduced.

In the above embodiment, the connection between the two networks has been described, but the number of connections between the networks is arbitrary.

The network connection system of the present invention can be realized by using a normal computer system without using a dedicated system. For example, a color imaging apparatus that executes the above-described processing may be configured by installing the program for executing any of the above-described programs into a computer from a medium (a floppy disk, a CD-ROM, or the like) storing the program. it can.

The medium for supplying the program to the computer may be a communication medium (medium for temporarily and fluidly holding the program, such as a communication line, a communication network, or a communication system). For example, the program may be posted on a bulletin board (BBS) of a communication network and distributed via the network. Then, by starting this program and executing it in the same manner as other application programs under the control of the OS, the above-described processing can be executed.

[0116]

As described above, an inter-network connection system capable of reducing the load on the relay device can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an inter-network connection system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an address-attached network connection system according to the first embodiment of the present invention;

FIG. 3 is a sequence diagram illustrating an initialization process, a connection process, and a disconnection process of the network connection system according to the first embodiment of the present invention;

FIG. 4 is a sequence diagram illustrating actual connection processing of the network connection system according to the first embodiment of the present invention;

FIG. 5 is a block diagram illustrating an example of an inter-network connection system according to a second embodiment of the present invention;

FIG. 6 is a sequence diagram illustrating an initialization process, a connection process, and a disconnection process of the network connection system according to the second embodiment of the present invention;

FIG. 7 is a sequence diagram illustrating an actual connection process of the network connection system according to the second embodiment of the present invention;

[Description of Signs] 1 First network 2 Second network 3 Relay device 11 Client 12 Proxy server 21 Server 22 Proxy client

Claims (6)

[Claims] 1. A first computer connected to a first network and a second computer connected to a second network relay a connection between the first network and the second network. An inter-network connection system for performing a communication connection via a repeater, wherein the first network further includes a third computer, and wherein the third computer is connected to the second computer via the repeater. A communication connection with a computer is established in advance, and the established communication connection is substantially constantly maintained. The first computer makes a communication connection with the second computer via the third computer. An inter-network connection system, characterized in that: 2. The third computer further comprises a storage unit for storing communication addresses of the repeater and the second computer, and the third computer uses the communication address stored in the storage unit to communicate with the repeater. Establishing a communication connection with the second computer in advance through the established connection with the relay machine,
The network connection system according to claim 1, wherein the established communication connection is maintained substantially constantly. 3. A first computer connected to a first network and a second computer connected to a second network relay a connection between the first network and the second network. An inter-network connection system for performing a communication connection via a repeater, wherein the first network further includes a third computer, the second network further includes a fourth computer, The third computer pre-establishes a communication connection with the fourth computer via the repeater, maintains the established communication connection substantially permanently, and the first computer A communication connection with the fourth computer via a computer; 4. The third computer further comprises a storage unit for storing communication addresses of the repeater and the fourth computer, and the third computer communicates with the repeater using the communication addresses stored in the storage unit. Establishing a communication connection with the fourth computer in advance through the established connection with the relay machine,
4. The network connection system according to claim 3, wherein the established communication connection is maintained substantially constantly. 5. A client and a proxy server connected to a first network and a server and a proxy client connected to a second network relay a connection between the first network and the second network. An inter-network connection method for performing a communication connection via a relay device, comprising: a first connection step for performing a communication connection between the proxy server and the relay device; and a communication connection between the relay device and the proxy client. Performing a second connection step; establishing a communication connection between the proxy server and the proxy client via the relay device connected in the first step and the second step in advance; and substantially establishing the established communication connection. And the proxy server, the relay device, and the proxy client held by the holding step. A third connection step for establishing a communication connection between the client and the server via the connection. 6. A client and a proxy server connected to the first network and a server and a proxy client connected to the second network relay a connection between the first network and the second network. A computer-readable recording medium for recording a program for performing a communication connection via a relay device, wherein: a first connection step for performing a communication connection between the proxy server and the relay device; A second connection step for establishing a communication connection with the client; and a communication connection between the proxy server and the proxy client via the relay device connected in the first step and the second step is established in advance. Holding the communication connection substantially permanently, and the proxy server held by the holding step, And a third connection step for establishing a communication connection between the client and the server via a connection between the repeater and the proxy client.