JPH11313122A - Data communication system/method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize the presence or absence of a specified additional function of a communication destination and to automatically transmit/receive data using an appropriate method by providing a data transmission/reception port with a port to recognize the presence/absence of the loading of the specified additional function. SOLUTION: When a computer 10 is a client, the presence or absence of the loading of a specified additional function 220 such as a ciphering function is inquired to a communication destination computer 20 by using the function recognition port 132 of a communication stack 13. It is decided whether the specified additional function is to be used or not in accordance with the response. When the computer itself is a server, it is decided whether the specified additional function is used or regular transmission/reception are executed according to whether the presence or absence of the loading of the specified additional function 120 using a function recognition port 231 is inquired or not. When the computer itself becomes the client or the server, data can be transmitted/received by an appropriate method in accordance with the presence or absence of the loading of the specified additional function of a communication destination. The specified additional functions are loaded on socket modules 12 and 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication system for controlling transmission and reception of data between computers via a computer network such as the Internet, and a data communication method applied to the system.

[0002]

2. Description of the Related Art In recent years, various types of computers for personal use called desktop type and notebook type have rapidly spread, and with the improvement of network technology, they have been scattered in remote places. Transmission and reception of data between computers has been facilitated. The data communication system operates on each computer and controls transmission and reception of these data.

FIG. 6 shows a schematic configuration of the data communication system. In the example shown in FIG. 6,
Two computers (here, for convenience, one is the client computer 10 and the other is the server computer 2)
0, but the client computer 10 can be a server computer, and the server computer 20 can be a client computer). , Each computer (10,
20), for example, WWW (World W
ide Web) a communication program 11 (client program) such as browser software;
It is assumed that data is transmitted / received to / from a communication program 21 (server program) such as WW server software.

[0006] The data communication system shown in FIG. 6 is roughly divided into the above-described communication program (1).
1, 21), a socket module (12, 22) and a communication stack (13, 23).

The communication stacks (13, 23) perform physical control of a communication line 30 (public telephone line, LAN, etc.) and control of a communication protocol. The socket modules (12, 22) are modules for linking the communication programs (11, 12) and the communication stacks (13, 23), and the communication modules (12, 22).
An interface (AP) for allowing 1) to transmit and receive data without being aware of the state of the physical line
I: Application Programming
Interface).

For example, the client computer 10
When the above communication program 11 executes a connection process for sending data to the communication program 21 on the server computer 20 which is the communication partner, the communication program 11
First calls a service called connect from among the socket modules 12 operating on the same computer. Communication program 11 and socket module 12
The communication between the communication program 11 and the communication program 11 uses a socket 121 for data transfer. The socket 121 is generated when the communication program 11 starts a communication session. And the socket module 12
Calls the communication stack 13 based on the communication destination information received from the communication program 11 at the time of calling the connect, and executes a connection process of the server computer 20 as the communication destination with the communication program 21.

The information passed from the communication program 11 to the socket module 12 includes an address for specifying the server computer 20 as a communication destination, a port number for specifying the communication program 21 on the server computer 20, and the like. . Therefore, when a plurality of communication programs are operating on the server computer 20 that is the communication destination, the information for specifying which communication program is to be connected to the communication session is the port number. This port number is stored in the communication stack (13, 23) in the data transmission / reception port (1
31 and 231).

At this time, the communication program 11
It is not necessary to be conscious of how the communication stack 13 operates. That is, the physical line is a public telephone line, LA
It is not necessary to consider whether the network is N or another network.

As described above, in the data communication system shown in FIG. 6, the data flow when communication programs exchange data is as follows: (a) communication program → (b) socket module →
(C) Communication stack → (d) Communication line → (e) Destination communication stack → (f) Destination socket module → (g)
It takes the form of a destination communication program.

[0010]

In this data communication system, both communicating programs recognize each other's functions. This is because the program is written in consideration of the target program for communication. That is, since the functions implemented by the communication destinations recognize each other, data transmission and reception between the communication programs can be performed by a predetermined protocol.

Here, for example, consider adding some additional functions to these communication programs. And
In order to use this additional function, it is necessary to newly use a different protocol. In such a case, there is no problem if both of the communicating communication programs are modified so as to correspond to the addition of the additional function. However, in consideration of the recent use form of data communication, a partner to be connected as a communication destination does not necessarily have an additional function added.

For example, WWW on the Internet
In a connection between a server and a WWW browser, it often happens that connection processing with a plurality of WWW servers is executed by only one browser software.

In such a situation, when an additional function is added on the WWW browser side and data transmission is attempted using a protocol for using the additional function, the WWW server of the communication destination supports the additional function. Otherwise, the communication session cannot be performed normally.

[0014] On the contrary, only the WWW server side supports the addition of the additional function, and since the WWW browser side does not have the additional function, normal communication may not be performed. Such a situation always occurs in an environment where a plurality of servers and clients coexist.

In view of the above, in addition to the basic functions and protocols possessed by all communication programs, it is necessary to mutually confirm whether or not the additional functions are implemented, or to use one of them. If not, there is a strong demand for a mechanism that automatically operates only with the basic functions of the prior art.

The present invention has been made in view of such circumstances, and is intended to automatically determine an appropriate method by confirming the presence or absence of a specific additional function at a communication destination and execute data transmission and reception. It is an object of the present invention to provide a data communication system and a data communication method that can perform the communication.

[0017]

According to the present invention, in order to achieve the above-described object, a port (function confirmation port) for confirming whether or not a function (specific additional function) to be added irregularly is installed is provided in advance. If a new client is to be installed, paired with the provided data transmission / reception port (data transmission / reception port), first use the function check port to inquire the communication destination of the presence / absence of the specific additional function. The response to this inquiry determines whether to perform data transmission / reception using the specific additional function or data transmission / reception without using the specific additional function. Whether the connection to the data transmission / reception port was requested after the inquiry about the implementation of the specific additional function used, or the inquiry using the function confirmation port By a connection to the data transceiver port it is requested without, but which is adapted to determine whether to perform one of the data transmission and reception without a data transmission and reception and specific additional function with specific additional functions.

That is, according to the present invention, regardless of whether the client itself becomes a client or a server, data transmission and reception can be performed by determining an appropriate method according to whether or not a specific additional function of a communication destination is installed. Becomes

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a data communication system according to an embodiment of the present invention. In the example shown in FIG. 1, two computers (for convenience, one is a client computer 1)
0, and the other is a server computer 20, but the client computer 10 can be a server computer, and the server computer 20 can be a client computer).
Communication using CP / IP shall be performed, and
Running on each computer (10,20),
For example, a communication program 11 (client program) such as WWW browser software and a WW
It is assumed that data is transmitted / received to / from a communication program 21 (server program) such as W server software.

The data communication system of this embodiment is roughly divided into a communication program (11, 21) and a socket module (12, 2) as in the prior art.
2) and a communication stack (13, 23).

The communication stacks (13, 23) perform physical control of a communication line 30 (public telephone line, LAN, etc.) and control of a communication protocol. The socket modules (12, 22) are modules for linking the communication programs (11, 12) and the communication stacks (13, 23), and the communication modules (12, 22).
An interface (AP) for allowing 1) to transmit and receive data without being aware of the state of the physical line
I).

In the data communication system of this embodiment, new functions (120, 220) are added to the socket modules (12, 22). Here, as an example, in data transmission / reception with the basic function, text data is transmitted / received in plain text, and a newly added function (12
In the data transmission / reception at (0, 220), it is assumed that this text data is encrypted and transmitted / received.

The communication program 11 on the client computer 10 and the communication program 21 on the server computer 20 communicate with each other using the same data transmission / reception ports (131, 231) as in the prior art, as in the conventional case. Try to send and receive This is because the communication programs (11, 21) usually use fixed ports for connection with the communication destination. This is because the connection destination computer is specified by the IP address, and further, which communication program among a plurality of communication programs running on the computer is connected to perform data transmission / reception by the port number. As described above, since the port and the communication program are closely linked, the protocol such as the format of data flowing over the port and the transmission / reception procedure is often fixed.

Therefore, as in the data communication system of this embodiment, (the basic function is transmitted as plain text)
New function to encrypt and send text (120,22)
0) is added to the socket module (12, 22), the communication program (11, 21) does not know the addition of the function, so the normal data transmission / reception port (131, 22) is not used.
231), a communication session is established, and data is transmitted and received based on the text encryption protocol.

For example, the client computer 10
When the above communication program 11 requests data transmission / reception with the communication program 21 on the server computer 20, the socket module 12 receives the information through the normal data transmission / reception socket 121. On the other hand, the socket module 12 prepares a function confirmation socket 122 in pairs with the data transmission / reception socket 121. The socket module 12 uses the function confirmation socket 122 on the premise that the socket module 22 on the server computer 20 has the new function 220 mounted and the function confirmation socket 222 is prepared. Attempt to connect to the function confirmation port 232 corresponding to the function confirmation socket 222. The port number used at this time is the socket module (12, 22).
Thus, the port number is held as a pair with a data transmission / reception port number, and is managed as a function confirmation port in the communication stack (13, 23) by the control of the socket module (12, 22).

On the other hand, since the socket module 22 on the server computer 20 has the new function 220 mounted thereon, it can accept the connection to the function confirmation port 232, and at this point, the client computer 10
It recognizes that the socket module 12 has the new function 120. Similarly, when the connection to the function confirmation port 232 is established, the socket module 22 of the client computer 10 replaces the socket module 22 on the server computer 20 with the new function 22 at this time.
Recognize that 0 is implemented.

Upon recognizing the implementation of the new functions (120, 220), the socket module 12 on the client computer 10 and the socket module 22 on the server computer 20 communicate using the new functions (120, 220). Texts transferred from the programs (11, 21) are encrypted and transmitted and received.

Next, referring to FIG. 2, only the socket module 12 on the client computer 10 has the new function 1
20 will be described. In this case, when the communication program 11 on the client computer 10 requests data transmission / reception with the communication program 21 on the server computer 20, the socket module 12 receives the information through a normal data transmission / reception socket 121,
Using the separately prepared function confirmation socket 122, the socket module 22 on the server computer 20 implements the new function 220 and the function confirmation socket 22
2 is prepared, an attempt is made to connect to the function confirmation port 232 corresponding to the function confirmation socket 222.

On the other hand, since the socket module 22 on the server computer 20 does not have a new function, the connection to the function check port 232 cannot be accepted. Therefore, the connection to the function confirmation port 232 fails, and at this time, the socket module 12 on the client computer 10 recognizes that the server computer 20 has not implemented the new function.

As described above, when the server computer 20 recognizes that the new function has not been implemented, the socket module 12 on the client computer 10 has the new function 12
Instead of using 0, the text delivered from the communication program 11 is transmitted as plain text.

Next, a case where only the socket module 22 on the server computer 20 implements the new function 220 with reference to FIG. In this case, when the communication program 11 on the client computer 10 requests data transmission / reception with the communication program 21 on the server computer 20, the socket module 12 receives the information through a normal data transmission / reception socket 121, and The connection to the data transmission / reception port 231 corresponding to the data transmission / reception socket 221 of the socket module 22 on the device 20 is attempted.

On the other hand, since the socket module 22 on the server computer 20 is connected to the data transmission / reception port 231 without connecting to the function confirmation port 232, the client computer 10
We are convinced that the above socket module 12 does not implement the new function.

As described above, the client computer 1
0 recognizes that the new function is not implemented, the socket module 22 on the server computer 10 executes the new function 22 despite the fact that the new function 220 is implemented.
Instead of using 0, the text delivered from the communication program 21 is transmitted and received as plain text.

Here, the operation procedure of the data communication system of this embodiment will be described with reference to FIGS.
FIG. 4 is a flowchart for explaining the operation on the client side.

The communication program 11 first generates a data transmission / reception socket 121, and uses the generated socket 121 to transmit / receive a data transmission / reception port 231 of a communication partner.
(Step A)
1). At this time, the communication program 11
Specify the address and the data transmission / reception port number.

On the other hand, the socket module 12
Before executing the connect process, it is confirmed whether or not the socket module 22 on the server computer 20 as the communication destination has an encryption function as a new function. Specifically, the socket module 12 prepares a socket 122 for confirming the function in addition to the socket 121 used for normal data transmission / reception.
, A function confirmation port 232 corresponding to the function confirmation socket 232 that the socket module 22 on the server computer 20 may have prepared.
Nect is performed (step A2).

When a session for function confirmation is established (YE in step A3)
S), the new function 120 that the user intends to use at that time
It recognizes that the encryption function is implemented in the socket module 22 on the server computer 20, and performs a connect using the normal socket 131 requested by the communication program 11 (step A4). And
If the connection for data transmission / reception is successful, the communication program 11 transmits / receives data using the session. At this time, the socket module 12
The server computer 20 encrypts the plaintext data delivered at that time using its own encryption extension function.
Data transmission / reception to / from the side is executed (step A5).

On the other hand, if the session establishment for the function confirmation fails (NO in step A3), the encryption function, which is the new function 120 which the user intends to use at that time, is installed in the socket module 22 on the server computer 20. Recognizing that the connection has not been made, the connection using the ordinary socket 131 requested by the communication program 11 is performed (step A6), and the connection for data transmission / reception
If ect is successful, the communication program 11 transmits and receives data using the session. At this time, the socket module 12 transmits and receives the plaintext data to and from the server computer 20 in a normal format without using the encryption extension function of the socket module 12 (step A7).

FIG. 5 is a flowchart for explaining the operation on the server side. The communication program 21 creates a listening socket 221 for data transmission and reception, and
It is in the en state (step B1). Normally, a connection is made from the client side to the listening socket 221. The socket module 21 of this embodiment has a function added to itself in addition to the normal transmitting session connection waiting socket 221. Another standby socket 222 for receiving the confirmation of is prepared inside (step B2). The function confirmation standby socket 222 uses a different port number so as not to be confused with the normal socket 221.

Then, this function confirmation waiting socket 2
22 is connected from the socket module 12 on the client computer 10 (step B
(YES in 3), the socket module 22 records and holds the IP address and port number of the other party (step B4). Then, the socket module 22
When there is a connection from the socket module 12 on the client computer 10 to the standby socket 221 for data transmission / reception (step B5), the IP address and the port number of the client computer are checked, and the function is confirmed immediately before. The information is compared with the information of the other party of the coming session (step B6).

If they are the same (YES in step B6), it is determined that the connected session may transmit and receive data using the added function 220, and Data transmission / reception is performed using the protocol with the added function (step B7).

On the other hand, if they are different (NO in step B6), it is determined that this connected session must not transmit and receive data using the added function 220, and the function is added. The data is transmitted and received in a normal format without using the protocol (step B8).

As described above, according to the data communication system of this embodiment, in both the client and the server, an appropriate method is determined according to whether or not the specific additional function of the communication destination is mounted, and the data transmission and reception are executed. You can do it.

In the above-described embodiment, the additional functions are incorporated in the socket modules (12, 22). However, as can be seen from the hierarchical structure of the data communication system, the functions are expanded by the communication program ( Application), socket modules and any part of the communication stack.

Therefore, for example, even when the function is extended by the communication program (11, 21), the connection to the function confirmation port of the communication destination is similarly performed before the normal connect, thereby confirming the mounted function. Can be performed.

In the above-described embodiment, whether the added function is installed is checked by checking the function check ports (132, 2).
32), and if the function mounting information is exchanged using the session when the data transmission / reception ports (131, 231) are connected, the presence or absence of a plurality of additional functions can be determined by the client and server. It becomes possible to recognize each other.

Further, since the method of the present invention is implemented as software, it can be stored in a computer-readable recording medium such as a floppy disk, an optical disk, or a semiconductor memory and distributed as a program that is controlled by the computer. It is possible.

[0048]

As described above in detail, according to the present invention, a function checking port for checking whether or not a specific additional function is mounted is newly provided in pair with a data sending / receiving port for data sending / receiving. If the server becomes a client, the function confirmation port is used to query the communication destination for the presence / absence of the specific addition function. If the server itself is a server, the specific addition using the function confirmation port is performed. Depending on whether or not an inquiry as to whether or not the function is implemented is made, the client itself or the server can determine whether to execute data transmission / reception using the specific additional function or data transmission / reception without using the specific additional function. Even in this case, it is possible to execute appropriate data transmission / reception in accordance with the presence / absence of the specific additional function of the communication destination.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a data communication system according to an embodiment of the present invention.

FIG. 2 is an exemplary view for explaining a case where only a socket module on the client computer according to the embodiment implements a new function;

FIG. 3 is an exemplary view for explaining a case where only a socket module on the server computer of the embodiment implements a new function;

FIG. 4 is a flowchart for explaining the operation on the client side of the embodiment.

FIG. 5 is an exemplary flowchart for explaining the operation of the server according to the embodiment;

FIG. 6 is a diagram showing a schematic configuration of a conventional data communication system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Client computer 11 ... Server computer 11, 21 ... Communication program 12, 22 ... Socket module 13, 23 ... Communication stack 121, 221 ... Data transmission / reception socket 122, 222 ... Function confirmation socket 131, 231 ... Data transmission / reception port 132, 232: Function confirmation port

Claims (10)

[Claims] 1. A data communication system for controlling data transmission / reception with an unspecified number of other computers,
In a data communication system in which a specific additional function is mounted, a function checking port used to check whether the specific additional function is installed on the other computer side is paired with a data transmitting / receiving port used for transmitting / receiving data. Inquiring means for inquiring of the other computer side whether or not the specific additional function is installed using the function checking port; and when an acknowledgment is returned in response to the inquiry of the inquiring means, the identification is performed. Communication control means for performing data transmission / reception using the additional function, and performing data transmission / reception without using the specific additional function when a negative response is returned or a response is not returned. Characteristic data communication system. 2. A data communication system for controlling data transmission / reception with an unspecified number of other computers,
In a data communication system in which a specific additional function is implemented, a function check port used to receive an inquiry about the presence / absence of the specific additional function from the other computer side is a data transmission / reception port used to transmit / receive data. Return means for returning an acknowledgment to the other computer when the other computer uses the function check port to inquire whether the specific additional function is implemented. And, when a connection to the data transmission / reception port is requested after an inquiry using the function confirmation port,
Executing data transmission / reception using the specific additional function, and performing data transmission / reception without using the specific additional function when connection to the data transmission / reception port is requested without inquiry using the function confirmation port A data communication system comprising: 3. A recording means for recording information on the other party obtained when the function confirmation port is connected, when confirming the mounting of the specific additional function with the other computer using the function confirmation port. The data communication system according to claim 1 or 2, further comprising: the communication control unit executes data transmission and reception using the specific additional function based on information obtained by the recording unit. 4. An information exchange for exchanging information for recognizing each other using the data transmission / reception port when confirming the implementation of the specific additional function with the other computer using the function confirmation port. 3. The data communication according to claim 1, further comprising a unit, wherein the communication control unit executes data transmission / reception using the specific additional function based on information obtained by the information exchange unit. system. 5. The information exchange means according to claim 4, wherein said information exchange means exchanges information for recognizing which additional function among a plurality of additional functions included in said specific additional function is to be used. Data communication system. 6. A data communication system for controlling data transmission / reception with an unspecified number of other computers,
In a data communication system in which a specific additional function is mounted, in order to confirm whether or not the specific additional function is mounted on the other computer and to receive an inquiry from the other computer regarding whether or not the specific additional function is mounted Inquiry means for providing a function confirmation port used for data transmission / reception ports used for data transmission / reception in pairs, and inquiring the other computer side of the presence / absence of the specific additional function using the function confirmation port. Performing a data transmission / reception using the specific additional function when an acknowledgment is returned in response to the inquiry of the inquiring means; and when a negative response is returned or no response is returned, the identification is performed. First communication control means for executing data transmission / reception without using an additional function; A return means for returning an acknowledgment to the other computer side when the other computer side inquires whether the specific additional function is implemented by using a port, and using the function confirmation port. When a connection to the data transmission / reception port is requested after the inquiry,
Executing data transmission / reception using the specific additional function, and performing data transmission / reception without using the specific additional function when connection to the data transmission / reception port is requested without inquiry using the function confirmation port And a second communication control means. 7. A data communication system for controlling data transmission / reception with an unspecified number of other computers,
In a data communication method applied to a data communication system in which a specific additional function is mounted, a function check port used to check whether or not the specific additional function is mounted on the other computer side is used for transmitting and receiving data. Provided in pairs with the data transmission / reception port to be used, an inquiry for inquiring whether the specific additional function is implemented on the other computer side using the function confirmation port, and when an acknowledgment is returned in response to the inquiry,
A data communication method comprising: performing data transmission / reception using the specific additional function, and performing data transmission / reception without using the specific additional function when a negative response or a response is not returned. . 8. A data communication system for controlling data transmission / reception with an unspecified number of other computers,
In a data communication method applied to a data communication system in which a specific additional function is mounted, a function confirmation port used to receive an inquiry from the other computer about whether or not the specific additional function is mounted transmits and receives data. Provided in pairs with the data transmission / reception port used for, when the other computer uses the function confirmation port to inquire whether the specific additional function is implemented, When an acknowledgment is returned and a connection to the data transmission / reception port is requested after an inquiry using the function confirmation port,
Executing data transmission / reception using the specific additional function, and performing data transmission / reception without using the specific additional function when connection to the data transmission / reception port is requested without inquiry using the function confirmation port A data communication method, comprising: 9. A data communication system for controlling data transmission / reception with an unspecified number of other computers,
In a data communication method applied to a data communication system in which a specific additional function is implemented, in order to confirm whether or not the specific additional function is installed on the other computer side, and to execute the specific additional function from the other computer side A function checking port used to receive an inquiry about the presence / absence of mounting is provided as a pair with a data sending / receiving port used for data transmission / reception, and the specific additional function is provided to the other computer using the function checking port. Inquires about the implementation, and when an acknowledgment is returned to the inquiry,
Performing data transmission and reception using the specific additional function, when a negative response is returned or when no response is returned, perform data transmission and reception without using the specific additional function, using the function confirmation port When the other computer inquires whether the specific additional function is implemented, returns an acknowledgment to the other computer, and after the inquiry using the function confirmation port, When a connection to the send / receive port is requested,
Executing data transmission / reception using the specific additional function, and performing data transmission / reception without using the specific additional function when connection to the data transmission / reception port is requested without inquiry using the function confirmation port A data communication method, comprising: 10. A program for controlling data transmission / reception of a data communication system which implements a specific additional function and transmits / receives data to / from an unspecified number of other computers, the program comprising: A data transmission / reception port used for transmitting / receiving data, a function confirmation port used for confirming the presence / absence of the specific additional function and for receiving an inquiry about the presence / absence of the specific additional function from the other computer. Provided as a pair, using the function checking port to inquire the other computer side about whether or not the specific additional function is installed, and when an acknowledgment is returned in response to the inquiry,
Performing data transmission and reception using the specific additional function, when a negative response is returned or when no response is returned, perform data transmission and reception without using the specific additional function, using the function confirmation port When the other computer inquires whether the specific additional function is implemented, returns an acknowledgment to the other computer, and after the inquiry using the function confirmation port, When a connection to the send / receive port is requested,
Executing data transmission / reception using the specific additional function, and performing data transmission / reception without using the specific additional function when connection to the data transmission / reception port is requested without inquiry using the function confirmation port And a computer-readable recording medium on which a program for operating the data communication system is recorded.