JPH114259A - Virtual connection communication equipment and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly complete a data transmission processing of a transmitter by assigning a virtual connection equipment which pretends that a connection is established between the transmitter and the transmitted and buffering transmission data regardless of a connection state with the other transmission. SOLUTION: A client socket processing part 18 always establishes a TCP/IP connection 51 when there are non-transmitted data in a transmission data FIFO buffer 13, and when a server socket connection state 16 is established during establishing a connection, the TCP/IP connection is always held. As long as the TCP/IP connection is established or there are non-transmitted data in the transmission data FIFO buffers 13 and 33 by an interaction of each part, the TCP/IP connections 51 and 52 continue to establish the connection and the TCP/IP connections 50 and 52 are not released even if the TCP/IP connection 51 is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission destination having a low line quality, a destination having a low reception processing capacity as compared with a transmission destination, and a destination having a frequent line failure, using connection-type communication. The present invention relates to a communication method for maintaining a connection with a partner in communication with the other party and further improving the processing occupation time on the transmission side.

[0002]

2. Description of the Related Art A conventional communication method will be described with reference to FIG. In FIG. 4, data communication using TCP / IP is performed between transmission processing (1) and reception processing (2). First, the transmission process (1) transmits a connection opening request (3) and receives a connection opening response (4). After that, a data transmission request (5) is transmitted, and ACK is transmitted.
(6) is received. Thereafter, a connection release request (7) is transmitted, and a connection release response (8) is received.

[0003] Assuming that the time until the transmission data reaches each partner is A, since the transmission is performed six times in (3) to (8), the transmission process takes 6A until the data transmission process is completed. It takes time.

In such conventional connection-type communication, a plurality of TCP / IP connections are established for one communication partner as a method for enabling communication even when the line quality is poor, and one of the TCP / IP connections fails. A method of continuing communication using the other connection even in the case of the above is described in Japanese Patent Application Laid-Open No. Hei 8-298535, "OSI Communication System".

[0005]

A first problem is that even if there are a plurality of connections, if a failure occurs in all the lines (or in some common line), the connection cannot be established. Data transmission cannot be performed. If the connection cannot be established, a connection establishment request is transmitted periodically to establish the connection. During this time, the process that attempted to transmit the data has to wait until the data transmission is completed. Even if a connection has been established, it is released when a line failure occurs.

The second problem is that when a path with poor line quality or a low line speed is used, or when the processing capacity of the destination is low, the data transmission processing of the source increases the transmission completion waiting time. That is, the throughput of the transmission source decreases. If the line is not disconnected, an apparent data transmission speed corresponding to the number of lines can be secured, but if the line quality is poor, overhead such as data retransmission processing and correction of the delivery order may increase.

[0007] A third problem is that the cost is high. In order to continue to establish connections regardless of the presence or absence of a data transmission request for a plurality of routes, the line usage fee for the routes must always be paid.

[0008] The object of the present invention is to provide a transmission destination having low line quality, a destination having low reception processing capability compared with a transmission destination, and frequent line failures using connection-type communication. It is an object of the present invention to maintain a connection with a partner in communication with the partner, and to improve processing occupation time on the transmission side.

That is, a first object of the present invention is to efficiently transmit data even in a communication via a low-quality transmission medium such as a wireless communication, and a second object is to transmit data. Is to shorten the time until the processing on the side is completed.

[0010]

The virtual connection communication system of the present invention is realized by placing a pair of virtual connection devices between a source and a destination. This virtual connection device receives a connection request, a data transmission request, and a connection release request of a transmission source instead of a transmission destination, and a connection response, a data reception response (ACK), and a connection release to the transmission source in response to each of the above requests. A mechanism for returning a response, a mechanism for holding transmission data in a data transmission request in a transmission FIFO buffer,
A mechanism for automatically transmitting connection-type communication to a preset destination when there is untransmitted data in the FIFO buffer, and a mechanism for holding data received from the destination in a reception FIFO buffer And a mechanism for automatically transmitting data received from a transmission destination to a transmission source from a reception FIFO buffer when a connection is established with the transmission source.

A transmission interface is provided between the virtual connection devices.
When there is untransmitted data in the O buffer, a connection is established and data is transmitted. Whether or not the connection is automatically disconnected when there is no untransmitted data in the FIFO buffer is determined according to the line to be mounted.

In the virtual connection device and the communication using the same, the connection between the transmission source and the destination can be treated as if a connection is apparently established irrespective of the connection between the virtual connection devices. Data transmission can be performed only when a connection can be established between virtual connection devices without loss of transmission data.

Further, as means for solving the above-mentioned problems, as shown in FIG. 1, a virtual connection process 12 connected to a transmission process 11 on a transmitter 10 and a connection connection 50 as shown in FIG. A virtual connection process 32 connected to the receiving process 31 of the virtual connection process 52,
A connection connection 51 for connecting the two, and the virtual connection process 12 includes a transmission data FIFO buffer 13 serving as a temporary storage buffer for transmission data.
And a reception data FIFO buffer 14 that is a temporary storage buffer for reception data, a server socket processing unit 15 that receives transmission data, a server socket connection state 16 that holds a connection state, and a virtual server that holds data transmission destination information. Connection destination information 17;
And a client socket processing unit which is a processing unit for data transmission.

[Operation] According to the present invention, a virtual connection device that makes it appear that a connection is established between a transmission source and a transmission destination that intends to perform connection communication is arranged to establish a connection with the destination. By buffering the transmission data irrespective of the state, the data transmission processing of the transmission source can be completed quickly. The buffered data is transmitted to the destination via the receiving virtual connection device at the destination.

Thus, even if an actual connection has not been established due to a line failure, the transmission source can perform other processing assuming that data transmission has been completed to the transmission destination, thereby improving throughput. This has the same effect when the line quality is low or when the line speed is low.

In addition, since it is recognized that the connection is established in a pseudo manner at both the transmission source and the transmission destination, there is no need to keep establishing the connection. this is,
Even for applications that always need to establish a connection,
There is an effect that the data on demand function can be used.

Hereinafter, the operation of the present invention will be described in detail.

First, a description will be given of how the connection is maintained even when a line failure between the transmission source and the transmission destination frequently occurs.

When the transmission source establishes a connection with the virtual connection device (transmission source side) and starts data transmission,
The virtual connection device accumulates transmission data in an internal FIFO buffer while returning a connection establishment response and a data transmission response.

The virtual connection device (transmission source side) in which transmission data is stored in the internal FIFO buffer establishes a connection with a predetermined transmission destination (in this case, the virtual connection device on the transmission destination side). And the internal F
The transmission data is extracted from the IFO buffer and transmitted to the virtual connection device (transmission destination). The virtual connection device (destination side) also stores transmission data in an internal FIFO buffer. Virtual connection device (transmission destination) in which transmission data is stored in an internal FIFO buffer
Also, a connection is established with a predetermined transmission destination (in this case, a final transmission destination), transmission data is taken out from an internal FIFO buffer and transmitted to the transmission destination. Thus, the transmission has been completed as in the normal case.

In this state, if a line failure occurs between the virtual connections, the connection between the virtual connections is released, but the connection between the transmission source and the virtual connection device (source side) and the virtual connection device The connection between the (destination side) and the transmission remains established, and data transmission is possible. Until the connection between the virtual connection devices is re-established, the transmission data of the transmission source is stored in the FIFO buffer of the virtual connection device (source side) and stored in the FIFO buffer of the virtual connection device (transmission destination side). If untransmitted data remains, transmission is continued to the destination.

When the connection between the virtual connections is re-established, data transmission between the virtual connections is resumed. As a result, the effect that the connection between the source and the destination is established irrespective of the connection state between the virtual connection devices between them, and the failure between the source and the destination occur. However, data can be continuously transmitted as if a connection had been established.

Next, the effect of improving the throughput of the line when the quality of the line between the source and the destination is poor and when the line speed is low will be described.

The destination and the virtual connection device are installed in the same host, and perform communication by looping back inside the host. Therefore, the transmission source can transmit transmission data to the FIFO buffer device of the virtual connection device (source side) without depending on the quality and speed of the physical line with the transmission destination. The virtual connection device (transmission source side) in which the transmission data is stored in the internal FIFO buffer establishes a connection with a predetermined transmission destination (in this case, the virtual connection device on the transmission destination side) and establishes an internal connection. The transmission data is extracted from the FIFO buffer and transmitted to the virtual connection device (transmission destination). During this time, if there is a data transmission request from the transmission destination, the virtual connection device (transmission side) stores transmission data in the FIFO buffer.

As described above, by simultaneously storing the transmission data in the FIFO buffer and extracting the data from the FIFO buffer and transmitting the data to the virtual connection device (destination side), the transmission source becomes: The data transmission process can be completed at the same speed as the internal loopback communication without being affected by the actual line quality and speed.

Hereinafter, the operation of the present invention will be described in more detail.

Conventionally, in connection communication represented by TCP / IP, it is necessary to establish a connection with a partner before transmitting data. For this reason, from the occurrence of a data transmission request to the point at which transmission is actually possible, the data transmission processing portion waits until “connection is established” or waits for reception of a transmission data reception response (ACK or the like). These waiting times increase when the line quality is poor, and the time until the data transmission processing is completed increases.

Therefore, according to the present invention, the actual connection establishment state (connection establishment state: connection state in connection-type communication. ), A virtual connection communication process that behaves as if a connection has been established.

The virtual connection processing of the present invention
"Process of returning dummy connection establishment response to connection request", "Process of returning dummy transmission data reception response (ACK) when transmission data is received", and "Process of temporarily storing transmission data in transmission data buffer" And "processing for establishing a connection when there is transmission data in the transmission data buffer and transmitting the data to the other party".

As a result, the data transmission process can be completed in the time for transmitting data to the virtual connection type communication. In the virtual connection type transmission process, data received from the data transmission process is transmitted to an actual destination by ordinary connection type communication.

Hereinafter, the operation of the present invention will be described in more detail with reference to FIGS.

A conventional communication method will be described with reference to FIG. In FIG. 4, data communication using TCP / IP between transmission processing (1) and reception processing (2) is considered. First, the transmission process (1) transmits a connection opening request (3) and receives a connection opening response (4). After that, a data transmission request (5) is transmitted, and ACK is transmitted.
(6) is received. Thereafter, a connection release request (7) is transmitted, and a connection release response (8) is received.

Assuming that the time until the transmission data reaches each of the other parties is A, since the transmission is performed six times in (3) to (8), the transmission processing takes 6A until the data transmission processing is completed. It takes time.

The communication method of the present invention will be described with reference to FIG. In FIG. 3, a virtual connection (11) is provided between a transmission process (9) and a reception process (10).
The transmission process (9) transmits a connection opening request (12) to the virtual connection (11) and receives a connection opening response (13). Virtual connection (1
1) transmits a connection establishment request (12) 'to the reception process (10) and receives a connection response (13)'. Thereafter, the transmission process (9) transmits a data transmission request (14) to the virtual connection (11).

The virtual connection (11) temporarily stores the content of the data transmission request (14) in the data buffer (15) and receives the ACK (16). The virtual connection (11) reads information from the data buffer (15), and sends a data transmission request (1) to the reception process (10).
4) 'is transmitted and ACK (16)' is received. After this,
The transmission process (9) transmits a connection release request (17) to the virtual connection (11) and returns a connection release response (18). Similarly, virtual connection (11)
Receives the connection release request (17) ′ because there is no transmission data only in the data buffer (15).
0) and returns a connection release response (18) '.

(12) (13) (14) (16) (1
7) Transmission of (18) and (12) '(13)' (1
4) Transmission of '(16)' (17) '(18)' is performed independently without waiting.

The transmission time of (12) to (18) is 6B,
The transmission time of (12) 'to (18)' is 6C.

Transmission processing (10) and virtual connection (1)
Assuming that 1) is mounted on the same host and the receiving process (12) is connected by a line of poor quality, generally 6B <6C. Since 6A 時間 6C compared to the transmission time in the conventional method, communication via the virtual connection (11) is less affected by the line quality than before, and when the line quality is poor, the conventional method is used. The time required for the transmission process (9) to complete the transmission process becomes shorter.

As described above, according to the present invention,
The following operational effects can be obtained.

The time required for the transmission process on the data transmission side to complete the transmission does not affect the line quality with the reception side.

Conventionally, even if the line quality is good, if the processing performance on the reception processing side is poor, the time required for completing the transmission processing on the data transmission side increases as in the case where the line quality is poor. According to this virtual connection, the time required for the transmission process on the data transmission side to complete the transmission does not affect the processing performance on the reception side.

[0042]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[Explanation of Configuration] FIG.
In the case where the transmission process 11 inside transmits data using TCP / IP to the reception process 31 inside the receiving host 30, virtual connection communication is performed using the virtual connection device of the present invention. It shows a mounting form in the case.

In FIG. 1, the virtual connection device of the present invention includes a virtual connection process 12 and a virtual connection process 32 as software processes, respectively.
It is implemented in the form. The virtual connection connection destination information 17 includes a T between the client socket processing unit 18 and the server socket processing unit 35 in the receiving host 30.
As information necessary for establishing the CP / IP connection 51, the IP address of the receiving host 30 and the port number of the server socket processing unit 35 are set. Similarly, the virtual connection connection information 37 includes the IP address of the receiving host 30 and the port of the receiving process 31 as information necessary for establishing the TCP / IP connection 52 with the receiving process 31 in the receiving host 30. The number is set. A text file that is easy to refer to and change is desirable for recording such information.

In the server socket connection state 16, the connection state of the TCP / IP connection 50 is set. In the server socket connection state 36, whether the TCP / IP connection 50 is establishing a connection or not stored in the transmission data FIFO buffer 13. When transmission data exists, it is set that connection is being established. These hold their values in memory. A method of setting a value referring to the connection state and the state of the transmission data FIFO buffer 13 in the server socket connection state 36 will be described later.

The server socket processing unit 15 has a TCP / I
FIFO for sending data from P connection 50
The data is stored in the buffer 13. The client socket processing unit 18 holds the transmission data FIFO buffer 13 in the transmission data buffer 33. Since these FIFO buffers need to be updated at high speed, it is desirable to buffer them on a memory.

[Description of Operation] Next, the operation of the embodiment of the present invention will be described in detail with reference to FIG.

When there is untransmitted data in the transmit data FIFO buffer 13, the client socket processing unit 18 always establishes the TCP / IP connection 51 and transmits the data, and the server socket connection state 16 indicates that the connection is being established. If set, TCP /
It operates so as to always hold the IP connection 51.

Similarly, the client socket processing unit 38
When there is untransmitted data in the transmission data FIFO buffer 33, the TCP / IP connection 52 is always established and the data is transmitted, and when the server socket connection state 36 is set to "connection established". Operates to always establish the TCP / IP connection 52.

By the interaction of each part described above,
Whether the TCP / IP connection 50 has been established, the transmission data FIFO buffer 13 or the transmission data FI
As long as there is untransmitted data in the FO buffer 33, TCP
The / IP connection 51 and the TCP / IP connection 52 operate to keep establishing the connection.
Even if the CP / IP connection 51 is released, the TCP /
IP connection 50 and TCP / IP connection 52
Since is not released, it appears that the connection is apparently established between the transmission process 11 and the reception process 31.

The server socket connection state 3 in FIG.
6, a method of transmitting a connection state value according to the TCP / IP connection 50 and the transmission data FIFO buffer 13 will be described with reference to FIG. FIG. 2 shows transmission data 101 to 107, connection statuses 111 to 113, and transmission data 141 between virtual connections, which are obtained by extracting elements related to the description from FIG.
Is added.

The server socket connection state 3 in FIG.
6 corresponds to the server socket connection state 128 of FIG. Also, the TCP / IP connection 50 shown in FIG.
Corresponds to the TCP / IP connection 151 in FIG.
The transmission data FIFO buffer 13 corresponds to the transmission data FIFO buffer 122 in FIG. The TCP / IP connection 51 between the virtual connection process 12 and the virtual connection process 32 in FIG. 1 corresponds to the TCP / IP connection 152 in FIG. Since then
Description will be made using the numbers in FIG.

The contents of the transmission data 101 to 107 are all the same. The transmission data 101 is transmitted to the server socket processing unit 12 via the TCP / IP connection 151.
For one, the transmission data 103 is stored in the transmission data FIFO buffer 122. No data other than the transmission data 102 is transmitted during the transmission via the TCP / IP connection 151.

On the other hand, the client socket processing unit 125
When transmitting data to the server socket processing unit 126 using the TCP / IP connection 152, the connection state is always added to the head and transmitted. Specifically, it is as follows. The client socket processing unit 125, which has detected that there is untransmitted data in the transmission data FIFO buffer 122, reads out the transmission data 104 from the buffer and then refers to the server socket connection state 123 to check the TCP / IP connection 151.
Confirms that the connection is still established.

At this time, if the connection state is being established, a connection state 111 is generated while the connection is being established. If the connection is being released, it is checked whether the transmission data read from the buffer is the last untransmitted data. If the transmission data 104 is the last untransmitted data remaining in the buffer, the connection state 111 is generated during the release of the connection. If it is not the last untransmitted data, it is generated during connection establishment.

Thereafter, the client socket processing unit 12
5 generates transmission data 141 between virtual connections in which the connection state 111 is added to the head of the transmission data 105, and transmits the generated data 141 to the server socket processing unit 126 via the TCP / IP connection 152.

The server socket processing unit 126 that has received the transmission data 141 between virtual connections separates the connection state 113 added to the head and the transmission data 107, and stores the transmission data 107 in the transmission data FIFO buffer 127. The connection state 113 is referred to in order to set the connection state in the server socket connection state 128.

As described above, the means for transmitting the server socket connection state is realized by always giving the connection state to the data transmitted between the client socket processing unit 125 and the server socket processing unit 126. .

[0059]

Next, an embodiment of the present invention will be described with reference to FIG. In the examples, the drawings used in the description of the embodiments will be referred to as examples. That is, the virtual connection device is mounted as a communication process on each of the host having the normal transmission process and the host having the reception process. In the figure, the virtual connection process 12 and the virtual connection process 32 correspond respectively.

Next, the operation of the embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG. The case where the effect of the present invention is most apparent is when a large amount of data is transferred from the transmission process 11 to the reception process 31. If the connection is released (disconnected) during the transfer, the data is transmitted again. This is the case. As a specific example, there is a case where file transfer or the like is performed in an environment where a part of wireless is used as a transmission medium like a mobile phone. In data transmission over a general TCP / IP connection, if the connection is broken, it is necessary to start over from the beginning. Also, the method of simultaneously establishing and transferring a plurality of physical connections described in the description of the conventional method can only obtain the effect of lowering the probability of completely disconnecting the connection, and when using wireless Is
A plurality of connections are likely to be disconnected at the same time.
Therefore, as a case best expressing the effect of the present invention, it is assumed that the middle TCP / IP connection 51 is disconnected and re-connected while a large amount of data is being transmitted from the transmission process 11 to the reception process 31. Will be explained.

The transmission process 11 transmits the virtual connection process 1 to the reception process 31 for the purpose of transmitting data.
2 to send the data. First, the TCP / IP connection 50 is established, and the transmission data is stored in the transmission data FIFO buffer 13 by the server socket processing unit 15. The client socket processing unit 18 detects that untransmitted data has been accumulated in the transmission data FIFO buffer 13. The detection is performed by the server socket processing unit 1
5 stores transmission data in the transmission data FIFO buffer 13 and at the same time,
This is done by notifying that the transmission data has been saved.

The client socket processing unit 18 reads information for connecting to the virtual connection 32 of the connection destination from the virtual connection connection destination information 17 and executes TCP / IP.
The connection 51 is established, and the TCP / I is executed until the untransmitted data is exhausted from the transmission data FIFO buffer 13.
Virtual connection process 3 via P connection 51
2 while transmitting the connection status to the top.

The server socket processing unit 35 in the virtual connection process 32 divides the received data into a connection state and transmission data, and stores the transmission data in the transmission data FIFO buffer 33. At the same time, the value of the server socket connection state 36 is updated with reference to the separated connection state. Further, the server socket processing unit 35 notifies the client socket processing unit 38 that the transmission data has been stored in the transmission data FIFO buffer 33.
Notify.

The client socket processing unit 38 reads information for connecting to the reception process 31 from the virtual connection destination information 37, establishes the TCP / IP connection 52, and the transmission data FIFO buffer 33 has no untransmitted data. Up to this point, the reading of the transmission data and the transmission to the reception process 31 are repeated.

With the above, the TCP / IP connection 50,
51 and 52 are established and the transmission data FIFO buffer 1
The transmission data is transmitted from the transmission process 11 to the reception process 31 via the transmission processes 3 and 33.

In this situation, the TCP / IP connection 5
The operation of the transmission process 11 and the reception process 31 when 1 is disconnected will be described. The transmission process 11 uses TCP
Even if the / IP connection 51 is disconnected, the TCP / IP connection 50 is still established, and the transmission data is only stored in the transmission data FIFO buffer 13. Continue to transmit data as before it was disconnected.

The reception process 31 includes a transmission data FIF.
As long as there is untransmitted data in the O buffer 33, TCP / I
Data is continuously received as before the P connection 51 is disconnected.

When there is no untransmitted data in the transmission data FIFO buffer 33, the client socket processing unit 3
8 refers to the server socket connection state 36,
It is determined whether the transmission process 11 is still establishing a connection. The connection state added to the head of the data received by the server socket processing unit 35 immediately before the disconnection of the TCP / IP connection 51 is set during connection establishment. Because TCP / IP
Immediately before the connection 51 is disconnected, the TCP / IP
The connection 50 should be established, and even if the transmission process completes all transmission processing and disconnects the TCP / IP connection 50, the transmission data
This is because there is untransmitted data in the O-buffer 13, so that the connection state given by the client socket processing unit 18 should be in the state of establishing a connection.

Referring to the server socket connection state 36, the client socket processing unit 38 confirming that the connection is being established holds the TCP / IP connection 52 as it is being established. With the above, TCP / IP
Even if the connection 51 is disconnected, the TCP / IP connections 50 and 52 remain established. After that, a description will be given of a process until the TCP / IP connection 51 is reconnected and the data transmission is restarted.
The transmission process 11 continues to transmit until the P / IP connection 51 is reconnected, and the transmission is completed and T
It is possible that the CP / IP connection 50 has been released. These two cases will be described in order.

First, the case where the transmission process 11 continues to transmit until the TCP / IP connection 51 is reconnected will be described. Upon detecting that the TCP / IP connection has been disconnected due to some external factor, the client socket processing unit 18 attempts to re-establish the connection at appropriate intervals. For UNIX systems, it may be appropriate to use periodic signal interruptions to take time intervals.

The client socket processing unit 18 that has successfully re-established the TCP / IP connection 51
The processing is restarted from the state immediately before the disconnection of the IP connection 51. That is, it is checked whether or not there is untransmitted data in the transmission data FIFO buffer 13. Since there is untransmitted data, the connection state is added to the transmitted data and transmitted to the virtual connection process 32. The connection state given at this time is set to “connection established” on the premise that the TCP / IP connection 50 is being established.

Thus, the data transmission has been resumed. In this situation, when the transmission process completes all data transmission, the TCP / IP connection 50 is disconnected after the last data transmission. As long as there is untransmitted data in the transmission data FIFO buffer 13, the client socket processing unit 18 continues to transmit the transmission data with the connection state set during connection establishment to the virtual connection process until the last untransmitted data is reached. .
The last transmission data is stored in the transmission data FIFO buffer 13.
The client socket processing unit 18 read from T
Since the CP / IP connection 50 is being released and there is no untransmitted data in the transmission data FIFO buffer 13, the connection state set during the release of the connection is added to the last transmission data and transmitted to the virtual connection process 32. , The TCP / IP connection 51 is disconnected.

The client socket processing unit 38 also reads out the last untransmitted data from the transmission data FIFO buffer 33 in due course. The client socket processing unit 38 that has read the last untransmitted data refers to the server socket connection state 36 and confirms that the connection is being released. Since the connection is being released, the client socket processing unit 38 disconnects the TCP / IP connection 52 after transmitting the last untransmitted data to the reception process 31. This completes the transfer of all data.

Next, a case where the transmission process 11 has completed transmission of all data before the TCP / IP connection 51 is re-established and the TCP / IP connection 50 has been released will be described. In this case, the transmission data FIFO
It is checked whether or not there is unsent data in the buffer 13. If there is unsent data, the connection state set during connection establishment is given, and data transmission is resumed.
Eventually, when transmitting the last untransmitted data, the connection state set during connection release is added and transmitted, and then the TCP / IP connection 51 is disconnected.

The virtual connection process 32 also refers to the server socket connection state 36 when transmitting the last untransmitted data, and recognizes that the TCP / IP 50 connection has been released. After transmitting the data to the receiving process 31, the TCP / IP connection 52 is disconnected, and the transfer of all data is completed.

[0076]

The first effect is that data transmission can be efficiently performed even in communication via a low-quality transmission medium such as wireless communication. As shown in the embodiment, even in a situation where the connection is disconnected, the data transmission side can continue the data transmission process, and the reception side can continue the data reception.

The reason is that the virtual connection device has a mechanism that behaves as if a connection is connected and a transmission data buffering mechanism. Since these two mechanisms are provided, even in a situation where the connection is actually disconnected, the transmission processing and the reception processing are not interrupted, and all data can be finally transmitted. In other words, it can be said that efficient data transfer can be performed in that data retransmission and the like due to disconnection of the connection do not occur.

The second effect is that the time until the processing on the data transmitting side is completed can be shortened. This is also due to the transmission data buffering mechanism of the virtual connection process. After transmitting all data to the buffer, the transmission processing side can release the connection without waiting for the completion of data collection at the reception side. Subsequent data transmission is performed by the virtual connection device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a detailed explanatory diagram of a means for transmitting a server socket connection state in the embodiment.

FIG. 3 is a diagram showing a virtual connection communication method of the present invention.

FIG. 4 is a diagram showing a conventional virtual connection communication method.

[Explanation of symbols]

Reference Signs List 10 Host equipped with transmission processing; 11 Process of transmitting data by TCP / IP; 12 Virtual connection device mounted on transmission processing side; 13 Temporary storage buffer for transmission data in virtual connection device; A buffer for temporarily storing received data in the virtual connection device; 15 a processing unit for receiving transmission data in the virtual connection device; 16 a unit for holding a connection state in the virtual connection device; 17 data in the virtual connection device 18 a data transmission processing unit in the virtual connection device; 19 a process having a timer function implemented in the host; 30 a host equipped with reception processing; 31 TCP / Process of receiving data by IP; 32 Transmission process 33 A temporary storage buffer for transmission data in the virtual connection device; 34 A temporary storage buffer for reception data in the virtual connection device; 35 Receives transmission data from the virtual connection device Processing unit; 36 a unit that holds a connection state in the virtual connection device; 37 a unit that holds data transmission destination information in the virtual connection device; 38 a processing unit for data transmission in the virtual connection device; 39 host A TCP / IP connection established between the sending process and the virtual connection device; 51 a TCP / IP connection established between the virtual connection device
IP connection; 52 TCP / IP connection established between the virtual connection device and the receiving process; 101 to 107 transmission data; 111 to 113 data representing the connection state; 121 receiving transmission data in the virtual connection device 122, a temporary storage buffer for transmission data in the virtual connection device; 123, a portion holding the connection state in the virtual connection device; 124, a portion holding the data transmission destination information in the virtual connection device; 125 a processing unit for data transmission in the virtual connection device; 126 a processing unit for receiving transmission data in the virtual connection device; 127 a temporary storage buffer for transmission data in the virtual connection device; 141: a data holding connection state to transmission data; 151 TCP / IP connection established between transmission process and virtual connection device; 152 TCP established between virtual connection device.
/ IP connection;

Claims (4)

[Claims] In a connection type communication system, a mechanism for receiving a connection request, a data transmission request, and a connection release request of a transmission source instead of a transmission destination, and a connection response / data reception response to the transmission source for each of the above requests (ACK) A mechanism for returning a connection release response, a mechanism for holding transmission data in a data transmission request in a transmission FIFO buffer, and a preset when there is untransmitted data in the FIFO buffer. A mechanism for automatically transmitting to the destination by the connection-type communication, a mechanism for holding data received from the destination in a FIFO buffer for reception, and a method for receiving when the connection with the source is established. Automatically send data received from the destination to the source from the FIFO buffer A virtual connection communication device, comprising: 2. A virtual connection process connected to a transmission process on a transmitter side, a virtual connection process connected to a reception process on a receiver side, and a connection connection connecting the virtual connection processes. The virtual connection process includes a transmission data FI that is a temporary storage buffer for transmission data.
FO buffer and received data FI which is a buffer for temporarily storing received data
FO buffer, server socket processing unit for receiving transmission data, server socket connection status for holding connection status, virtual connection connection destination information for holding data destination information, and client socket processing as a data transmission processing unit The virtual connection communication device according to claim 1, comprising: 3. A transmission apparatus having a pair of virtual connection devices provided at a transmission source and a transmission destination, and transmitting via a pair of the virtual connection devices irrespective of a connection state between the virtual connection devices. A virtual connection communication method, wherein communication is performed as if a destination and a source have established a connection. 4. A connection type communication method, comprising: a process of returning a dummy connection establishment response to a connection request; a process of returning a dummy transmission data reception response (ACK) when receiving transmission data; 4. The virtual connection communication according to claim 3, comprising: a process of temporarily storing transmission data; and a process of establishing the connection when there is transmission data in the transmission data buffer, and transmitting the connection to a partner. Method.