JPH06152605A - Local area network with data transmission confirming function - Google Patents

Abstract

PURPOSE:To reduce the probability of failure in data transmission by decreasing data transmission amount outputted from a computer in a unit time when data are sent simultaneously from plural computers concentratedly without increasing the storage capacity of a reception buffer in each computer. CONSTITUTION:When transmission data are outputted externally through a data transmission confirmation section 7 and a frame transmission reception section 4 while a data transmission request section 5 designates a computer 1A and stored in a reception buffer 8 in the computer 1A through a communication channel 3 and a frame reception section 4 of the computer 1A. In this case, when another transmission data are sent from another computer to the computer 1A and the idle capacity of the reception buffer 8 is deficient, a reception buffer management section 108 in the computer 1A detects it and notifies it to the wait time revision notice section 19 to allow it to send a retransmission wait time revision frame to other computers, thereby increasing the wait time of each computer to a reception acknowledge frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a local area network having a data delivery confirmation function, and particularly to confirming that data has been delivered to a destination when data is transferred between a plurality of computers via a communication line. The present invention relates to a local area network having a data delivery confirmation function for performing a process.

[0002]

2. Description of the Related Art In a local area network, in many cases, dozens to hundreds of computers are connected by a communication line, and the destinations of these computers are designated in units of frames, for example, by addresses. To send data.

Each computer, when data addressed to itself is sent via a communication line, identifies this data and takes it into its own computer, and outputs the data from its own computer to another computer as described above. It has a frame transmission / reception unit that sends out to a communication line connecting between computers, temporarily stores the data sent to its own computer via this frame transmission / reception unit in a reception buffer, and sequentially stores the data stored in the reception buffer. Processing is performed by a reception data processing unit provided therein.

At the same time, such data transmission is concentrated on, for example, a certain computer, causing a data collision and the storage capacity of the receiving buffer provided in the receiving computer becomes insufficient, and the data is transmitted. The data may not be properly received by the computer to which the data is sent.

In the conventional local area network of this type, in order to prevent such data non-delivery and to confirm the delivery of the data, the computer receiving the data is addressed to its own computer. When the data that was sent is received normally, the address that indicates the destination of the transmission and the address of the computer that received this data are added to the computer that sent this data, and the data was received normally. Is generated and sent to the communication line via the frame transmitting / receiving unit.

The computer that has transmitted the above-mentioned data is
By receiving the reception response frame, it is recognized that the data transmission is normally performed, and the data transmission is ended.

However, in one transmission of data,
As described above, it is not always the case that the data sent by another computer collides with the transmission of data from the other computer to the same computer at the other end, and the computer at the other end does not receive the data. Waits for the reception response frame sent from the other party for a predetermined waiting time after sending, and even if this waiting time elapses, data is received from the destination computer. When the response frame does not arrive, the data is transmitted again.

When the data is retransmitted in this way and no reception response frame is received even after the elapse of a predetermined waiting time, the same data is retransmitted a predetermined number of times.

Even if the data is retransmitted a predetermined number of times in this way, if the reception response signal from the transmission partner cannot be received, the data transmission is treated as a failure.

[0010]

The above-mentioned conventional local area network having the function of confirming the delivery of data is arranged such that one computer (for example, computer A) receives data from a plurality of other computers one after another. When the transmission occurs, the computer A lacks the storage capacity of the reception buffer that temporarily stores the received data as compared with the processing of the received data, discards the data to be received, and discards the data. The reception response frame is not transmitted for the data.

In a local area network in which the number of computers connected to one network is large and the data transfer rate is high, such a state frequently occurs, and as described above, it is predetermined in the computer. Even if data is retransmitted for the number of times of retransmission, a situation occurs in which data is not normally received by the transmission destination computer, that is, the frequency of transmission failure increases.

When such a situation occurs, the waiting time is increased or the storage capacity of the reception buffer is increased.
We are making changes to our local area network.

[0013] Such a change of the local area network must be performed for all the computers included in the local area network, and has a drawback that it requires a lot of time and labor.

An object of the present invention is to, when the amount of data to be transmitted is large and the storage capacity of the reception buffer is insufficient, wait for retransmission to all the destination computers connected to the computer having this reception buffer. By sending a time change frame that takes a long time, the amount of data transmission that occurs during a certain period of time is reduced, and the network needs to be changed to increase the storage capacity of the receive buffer for all the computers that make up the network. Another object of the present invention is to provide a local area network having a data delivery confirmation function that can reduce the frequency of data transmission failure without doing so.

[0015]

A local area network having a data delivery confirmation function of the present invention is a local area network in which a plurality of computers are connected by a communication line and data is transmitted and received between the computers in frame units. In the area network, the frame transmission / reception unit that outputs the transmission data added from the inside via the communication line, receives the data sent to its own address via the communication line, and outputs it internally A transmission including a previously stored number-of-retransmissions storage section and an address designating a transmission destination in a predetermined format and data to be transmitted when a transmission request signal designating a transmission destination of data is applied. Stores the data transmission request unit that generates and outputs data, and the waiting time from when data is transmitted until the response signal is received. When the transmission data output from the waiting time storage unit and the transmission request unit is received, it is output to the frame transmission / reception unit, the waiting time stored in the waiting time storage unit is read, and the corresponding reception response signal is received within the read waiting time. Then, if the reception response signal from the destination of the transmission data is not sent even after the transmission of the transmission data is completed and the waiting time is exceeded, the transmission data is re-executed for the number of times stored in the retransmission number storage unit. If there is no reception response signal for the transmitted and retransmitted transmission data, a data delivery confirmation unit that stops the transmission of the transmission data, and the contents of the received data received by the frame transmission / reception unit are analyzed and if the reception response signal is received, A first reception frame analysis unit that outputs to the data delivery confirmation unit and outputs a waiting time change signal if it is a retransmission waiting time change notification frame, and a waiting time change signal Upon reception, a waiting time change processing unit for adding to the stored contents of the waiting time storage unit for a predetermined time and storing the added value in the waiting time storage unit, and transmission data from the other party received by the frame transmission / reception unit A second buffer for temporarily storing the data, and a second data output signal for analyzing the content of the signal received by the frame transmitting / receiving unit and outputting the data reception signal when the data is transmission data from the other party
A reception frame analysis unit, a reception buffer management unit that checks the free space of the reception buffer and outputs a shortage signal when the free space becomes a predetermined free space or less, and a predetermined waiting time change frame when the shortage signal is received. A waiting time change notification unit that outputs to all other external transmission / reception frames connected by a communication line via the frame transmission / reception unit, and from the destination stored in the reception buffer when the data reception signal is received. And a data reception response section for outputting the reception response signal specifying the address of the other party to which the transmission data is transmitted and outputting the reception data to the frame transmission / reception section, and the reception data depending on the content. A reception data processing unit for processing is provided in each of the computers.

[0016]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a local area network having a data delivery confirmation function of the present invention.

As shown in FIG. 1, a local area network having a data delivery confirmation function of this embodiment comprises a computer 1, a plurality of computers 1A to 1N, and a communication line 3 connecting these computers. Has been done.

The computers 1 and 1A to 1N have the same configuration, and the computers 1 and 1A to 1N are
If the transmission data output from the own computer is output to the communication line 3 and the transmission data sent from another computer via the communication line 3 is addressed to the own computer, the transmission data is identified. When the data to be transmitted to the other computer generated by the frame transmission / reception unit 4 and the information processing unit (not shown) are input, the address of the transmission destination computer and the own computer have A data transmission request unit 5 that generates and outputs transmission data in a predetermined format including an address in units of frames; a reception buffer 8 that temporarily stores the transmission data that the frame transmission / reception unit 4 has received from another computer; A retransmission number storage unit 6 that stores a predetermined number of retransmissions, a waiting time storage unit 12 that stores a waiting time, and a frame If the data received by the receiving unit 4 from the destination computer is monitored and the data is a retransmission waiting time change notification frame, or if it is data related to a reception response frame, these are detected and the waiting time change signal and the reception response are respectively detected. A first reception frame analysis unit 9 for outputting a signal and a waiting time storage unit 12 for adding a predetermined time to the waiting time stored in the waiting time storage unit 12 when the waiting time change signal is received. And a waiting time change processing unit 11 for writing to

Further, these computers 1 and 1A to 1N
Means that the transmission data output from the data transmission requesting unit 5 is input to the frame transmitting / receiving unit 4, and the received frame from the first received frame analyzing unit 9 is referred to the waiting time storage unit 12. Then, when the first reception frame analysis unit 9 outputs the reception response signal by the waiting time stored in the waiting time storage unit 12, the transmission of the above-mentioned data is ended, and even if the above-mentioned waiting time is exceeded, the data When the reception response signal from the destination is not received via the first received frame analysis unit 9, the retransmission count storage unit 6 is referred to until the number of retransmissions stored in the retransmission count storage unit 6 is reached. The same procedure as described above is performed, and when the reception response signal cannot be received even after the number of times of retransmission is reached, the data delivery confirmation unit 7 determines that the above-described data transmission has failed and ends the data transmission. When, A data reception signal is output when the content and reception state of the data transmitted to the own computer via the frame transmission / reception unit 4 are monitored and the transmitted data is normally received and stored in the reception buffer. 2 for receiving the data reception signal described above, a reception response frame addressed to the transmission source of the received data is generated and output to the frame transmission / reception unit 4, and the received data stored in the reception buffer 8 is received. A data reception response unit 16 that reads out and outputs to a reception data processing unit 17 described later
The receiving buffer management unit 10 monitors the free storage capacity of the reception buffer 8 and outputs a shortage signal when the free storage capacity becomes smaller than a predetermined value, and is connected via the communication line 3 when the shortage signal is received. The frame transmission / reception unit 4 generates a retransmission waiting time change frame for all computers
And a reception data processing unit 17 that processes the reception data read from the reception buffer 8 by the data reception response unit 16 according to the contents thereof.

Now, the data transmission request unit 5 of the computer 1
When the transmission data output by designating the address of the computer 1A is added to the data delivery confirmation unit 7, is added from the data delivery confirmation unit 7 to the frame transmission / reception unit 4, and further reaches the computer 1A via the communication line 3. The frame transmission / reception unit 4 of the computer 1A identifies this, outputs it to the reception buffer 8 in the computer 1A, and stores it. Second received frame analysis unit 1 in computer 1A
When the transmission data is normally received and stored in the reception buffer 8, the data transmission signal 5 outputs the data reception signal to the data reception response unit 16 in the computer 1A.

When the data reception response unit 16 receives the data reception signal, the data reception response unit 16 generates a reception response frame to the computer 1 that has sent this data, and sends it to the computer 1 via the frame transmission / reception unit 4 of the computer 1A.

The reception response signal is identified by the frame transmission / reception section 4 of the computer 1, identified by the first reception frame analysis section 9 of the computer 1, and input to the data delivery confirmation section 7 of the computer 1. If the transmission data is sent from the data delivery confirmation unit 7, the waiting time storage unit 1
When this reception response frame is received by the data delivery confirmation unit 7 within the waiting time stored in No. 2, the data delivery confirmation unit 7 determines that the transmission data is normally delivered to the destination computer 1A. The transmission of this transmission data ends.

Here, if the data delivery confirmation unit 7 cannot receive the reception response signal within the waiting time described above after outputting the transmission data, it retransmits the transmission data. The data delivery confirmation unit 7 refers to the number of retransmissions stored in the number-of-retransmissions storage unit 6 when transmitting the transmission data, and when the reception response signal cannot be received within the waiting time described above, the transmission data is retransmitted by the number of retransmissions described above. When the reception response signal cannot be received within the waiting time, it is determined that the transmission of the transmission data has failed, and the transmission of the transmission data is ended.

If, immediately before such transmission data is transmitted from the computer 1, the transmission data is similarly sent from the computer 1N to the computer 1A and receives this data, the reception buffer 8 in the computer 1A is assumed. When the free space in the computer 1A is insufficient, the reception buffer management unit 10 in the computer 1A detects this, and outputs a shortage signal in the computer 1A to the waiting time change notifying unit 19. The waiting time change notifying unit 19 waits for retransmission. The time change frame is sent to all the computers 1, 1A to 1N except 1A.

This retransmission waiting time change frame is detected by the respective first received frame analysis units 9 in all the computers 1, 1A to 1N except the computer 1A, and the waiting time change frames in the respective computers are detected. A change signal is output to the processing unit 11.

Upon receipt of this change signal, the waiting time change processing unit 11 changes the waiting time stored in the waiting time storage unit 12 connected to the waiting time change processing unit for a predetermined time. The added value is newly added to the waiting time storage unit 12
Write in.

Therefore, as described above, the computer 1N
Immediately after outputting the transmission data to the computer 1A, and when receiving such a retransmission waiting time change frame in the meantime, it waits for a reception response signal for a longer time than before.

Therefore, such a waiting time change processing unit 11
By appropriately increasing the amount of waiting time, the amount of transmission data output from each computer within a unit time decreases, the chance of data discard decreases, and data transmission failure processing is performed. Opportunities can be reduced.

[0030]

As described above, according to the data of the present invention,
Local area network with delivery confirmation function,
At least one of the computers that make up the network
The transmission data concentrates on one and the data in the reception data processing unit
Data is input and stored in the receive buffer in comparison with the data processing speed.
The amount of data that can be
When there is a shortage, the receiver
From a computer with a buffer
Output to all other computers and change the retransmission wait time.
Sending data from the computer that received the update frame
By increasing the waiting time when receiving
The amount of transmission data output from a computer
All computers in the network by
Send without increasing the storage capacity of the receive buffer in
The probability of data transmission failure can be reduced.
Have an effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a local area network having a data delivery confirmation function of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 computer 3 communication line 4 frame transmission / reception unit 5 data transmission request unit 6 retransmission number storage unit 7 data delivery confirmation unit 8 reception buffer 9 first reception frame analysis unit 1A computer 1N computer 10 reception buffer management unit 11 waiting time change processing unit 12 waiting time storage unit 15 second received frame analysis unit 16 data reception response unit 17 received data processing unit 19 waiting time change notification unit

Claims (1)

[Claims] 1. In a local area network in which a plurality of computers are connected by a communication line, and data is transmitted and received between the computers in frame units, transmission data added from the inside is output via the communication line. A frame transmission / reception unit that receives data sent to its own address via a communication line and outputs it internally, and a retransmission number storage unit that stores the number of retransmissions in advance,
A data transmission requesting unit for generating and outputting transmission data including an address designating a transmission destination and data to be transmitted in a predetermined format when a transmission request signal designating a transmission destination of data is added; , A waiting time storage unit that stores a waiting time from transmitting data to receiving a response signal, and when the transmission data output from the transmission request unit is received, outputs it to the frame transmission / reception unit and the waiting time storage unit When the waiting time to be stored is read and the corresponding reception response signal is received within the read waiting time, the transmission of the transmission data is terminated, and even if the waiting time is exceeded, the reception response signal from the destination of the transmission data is sent. When it does not come, the transmission data is retransmitted the number of times stored in the retransmission number storage unit, and when there is no reception response signal for the retransmitted transmission data, the transmission data And data delivery confirmation unit to stop signal,
A first received frame analysis that analyzes the content of the received data received by the frame transmission / reception unit, and outputs a reception response signal to the data delivery confirmation unit, and outputs a wait time change signal if a retransmission wait time change notification frame Section, a waiting time change processing section for adding a predetermined time to the stored contents of the waiting time storage section when the waiting time change signal is received, and storing the added value in the waiting time storage section, and the frame transmission / reception section. A reception buffer that temporarily stores the received transmission data from the other party, and a second reception frame analysis that analyzes the content of the signal received by the frame transmitting / receiving unit and outputs a data reception signal when the data is the transmission data from the other party. Section, a receiving buffer managing section for checking the free space of the receiving buffer and outputting a shortage signal when the free space becomes equal to or less than a predetermined free space, and receiving the shortage signal When a predetermined waiting time change frame is output to all other external transmission / reception frames connected by a communication line via the frame transmission / reception unit, and the data reception signal is received A data reception response unit that reads out the transmission data from the destination stored in the reception buffer, outputs it as reception data, and outputs the reception response signal designating the address of the destination that sent the transmission data to the frame transmission / reception unit. And a received data processing unit for processing the received data according to the contents in each computer, a local area network having a data delivery confirmation function.