JPH05292149A - Retransmission control system for abnormal data - Google Patents

Abstract

PURPOSE:To avoid re-transmission of useless data by informing transmission data via a sender side when a receiver side detects abnormal data and allowing the user to discriminate the abnormal data and the necessity of re-transmission. CONSTITUTION:Transmission data received through a LAN line 6 are sent from a data reception section 1 to a reception data check section 2, in which the presence of a returned identifier is checked. When the returned identifier is in existence, it is sent to a user processing section 5. When no returned identifier is in existence, whether or not fault data are in existence in the received data is checked and when no fault data are in existence the data are sent to the user processing section 5. When the abnormal data are in existence, the data are sent to a reception data return section 3. The return section 3 adds the returned identifier to the data and sends the resulting data to a data transmission section 4. The data return section 4 returns the received data to the destination via the line 6. Then the user processing section 5 allows the user to discriminate the propriety of the re-transmission of the returned data. When the re-transmission is required, the processing section 5 implements error correction and sends the result to the return section 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retransmission control method for abnormal data when data is transmitted in a connectionless and non-responsive manner in a LAN line communication protocol.

[0002]

2. Description of the Related Art In a conventional data transmission control method for a LAN line, a standard protocol of a communication protocol of a layer corresponding to a data link layer in the communication protocol is defined. The standard convention is a connectionless and non-response method. This is a highly efficient method suitable for a transmission line with high data transmission quality such as a LAN line, but since the transmission control corresponding to the data retransmission control in the data link layer is not included, the received data may be lost for some reason. If the abnormal data is included in, the normal data cannot be received by the retransmission control even if the receiving side detects the abnormal data.

[0003]

DISCLOSURE OF THE INVENTION The conventional LAN described above
In connectionless and no response method on the line,
When the receiving side generated the receiving data that was recognized as abnormal data, the receiving data was unconditionally discarded. for that reason,
System-important data was inevitably destroyed.

However, if the method of performing the retransmission control is adopted, the point-and-point confirmation response method is adopted, so that the efficiency in the connectionless and non-response method is lowered and, moreover, the load of the LAN line is increased. And
Since the transmitting side waits for the confirmation response from the receiving side, it is inevitable that the hold time of the transmitted data becomes long. Therefore, it is required to perform retransmission control without changing the connectionless method and the non-response method described above.

An object of the present invention is to, when abnormal data is detected in the received data, return the received data including the abnormal data from the control means in a layer higher than the data link layer to the transmitting side. Then, the user on the transmission side determines whether or not it is necessary to retransmit the returned transmission data. Thus, the resend control is performed even in the connectionless and non-response mode, the transmission data including the abnormality is prevented from being discarded, and the reliability of the data transmission is improved.

[0006]

An abnormal data retransmission control method of the present invention is a system in which a plurality of computers are connected to a local area network (LAN line) for data transmission, and the computer transmits the transmission data through the LAN line. From the received data inspection means, the received data inspection means for inspecting whether or not the received data includes abnormal data in the data receiving means and the transmitted data returned by the data receiving means, User processing means for allowing the user to determine whether or not the transmission data needs to be retransmitted, reception data including the abnormal data from the reception data inspection means, and the transmission data to be retransmitted from the user processing means. Receiving data returning means for receiving the received data and the receiving data including the abnormal data from the receiving data returning means and Receiving said transmission data to be retransmitted, characterized in that it comprises a data transmitting means for transmitting to a destination through the LAN line.

[0007]

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

Referring to FIG. 1 showing the configuration of an embodiment of the present invention, a data receiving section 1 corresponding to a control means of a data link layer of a communication protocol for receiving transmission data from a LAN line 6, and an abnormality in the received data. The data reception inspection unit 2 for inspecting whether or not there is data, and the reception data in which abnormal data is detected by the data reception inspection unit 2 is returned to the transmission source. Received data return unit 3 for adding the address of and to the received data
A data transmission unit 4 corresponding to the control means of the data link layer of the communication protocol for transmitting the received data to be returned to the reply destination through the LAN line 6, and an identifier indicating that the received data inspection unit 2 is to return the received data. When it is detected, the user processing unit 5 for determining whether or not the transmission data returned to the user needs to be retransmitted.

Next, the operation of this embodiment will be described with reference to FIGS.
Will be described.

The transmission data received through the LAN line 6 is received by the data receiving unit 1 (process procedure 10 in FIG. 2). The received data is sent as it is from the data receiving unit 1 to the received data checking unit 2, which is an upper layer of the communication protocol, and it is checked whether there is a return identifier. If there is a return identifier, since it is the returned transmission data, it is sent to the user processing unit 5 so that the user can determine whether or not to retransmit it (processing procedure 11). If there is no return identifier, it is normal received data, so it is checked whether there is abnormal data in the received data, and if there is no abnormal data, it is sent to the user processing unit 5. If there is abnormal data, it is sent to the received data return unit 3 (procedure 12). The reception data return unit 3 uses the transmission source address included in the reception data as a destination address, adds a return identifier, and sends the return address to the data transmission unit 4 (procedure 13). The data transmitter 4 returns the received data to the destination through the LAN line 6 (procedure 14). Next, the user processing unit 5 causes the user to determine whether or not it is necessary to retransmit the returned transmission data (processing procedure 16). If the retransmission is unnecessary, the returned transmission data is discarded (procedure 17). If you need to resend,
The user processing unit 5 corrects the error in the abnormal data and sends it to the received data returning unit 3 (procedure 16). The reception data return unit 3 sets the transmission source address of the returned transmission data as the destination address and sends it to the data transmission unit 4 (procedure 13). The data transmission unit 4 retransmits the transmission data returned to the transmission destination through the LAN line 6 (processing procedure 1
4).

Further, when the received data is not the returned transmitted data and does not include abnormal data,
The processing result of the user processing unit 5 is sent to the reception data returning unit 3 (processing procedure 11, 12, 15, 16). The reception data return unit 3 adds the transmission source address of the reception data to the processing result and sends it to the data transmission unit 4 (processing procedure 13). The data transmission unit 4 transmits the processing result to the transmission source of the received data through the LAN line 6. In the above description, the reception data inspection unit 2, the reception data transmission unit 3 and the user unit 5 correspond to the application layer in the reference model of the communication protocol, and the data reception unit 1 and the data transmission unit 4 correspond to the data link layer. It is associated with the hierarchy.

[0012]

As described above, according to the present invention, in the data transmission on the LAN line, when the receiving side detects the abnormal data, the receiving side including the abnormal data is transmitted as it is without requesting the retransmission to the transmitting side. Send back to. The sending side notifies the user of the returned send data and allows the user to judge the abnormal data and the necessity of re-sending, thereby eliminating unnecessary data resending, connectionless and non-response method. Has the effect of increasing the reliability of.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the embodiment.

[Explanation of symbols]

 1 data receiving unit 2 received data inspection unit 3 received data returning unit 4 data transmitting unit 5 user processing unit

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Claims (1)

[Claims] 1. A system for connecting a plurality of computers to a local area network (LAN line) for data transmission, wherein the computer receives data transmitted through the LAN line, and abnormal data in the data receiving unit. Reception data inspection means for inspecting whether or not the reception data includes the reception data and whether or not the transmission data has been returned, and makes the user determine whether or not the transmission data from the reception data inspection means needs to be retransmitted. User processing means, reception data returning means for receiving the reception data including the abnormal data from the reception data inspecting means and the transmission data to be retransmitted from the user processing means, and the reception data returning means for receiving the reception data The received data including abnormal data and the transmitted data to be retransmitted are received and passed through the LAN line. Retransmission control system for abnormal data, characterized by comprising: