JPH0720156B2 - Delivery confirmation method - Google Patents

Description

The present invention relates to a delivery confirmation method in a data link control procedure in a multilink environment in which a plurality of links (single links) exist between two adjacent stations. Is.

[Conventional technology]

In a system that transmits and receives data, it is important not only in the above-mentioned multi-link environment but to confirm whether the data transmitted from the own station has reached the partner station (delivery confirmation). have.

By the way, conventionally, in the delivery confirmation method in the data link control procedure in the multilink environment, only the information transfer frame in which the transmission sequence number is set is specified as the frame sent on the link, and the delivery confirmation is not performed in the multilink. The delivery confirmation was made based on the result of the delivery confirmation by the data link control procedure of each single link that constitutes the multi-link. That is, when the delivery confirmation notification of the information transfer frame requested to the single link is received from the single link, the delivery confirmation is made on the multilink, and if the confirmation cannot be obtained, the information transfer frame is retransmitted. .

[Problems to be Solved by the Invention]

In the conventional delivery confirmation method described above, as a feature of the multi-link environment, if at least one single link is connected, data can be transmitted and received between the own station and the partner station, and delivery confirmation can be performed. However, if all the single links have gone into the disconnection mode, the delivery confirmation is no longer guaranteed, and there is no way to deal with it. That is, conventionally, when all the single links have transitioned to the disconnection mode, it is treated as a failure occurrence, and the delivery confirmation of the data transmitted before that is not considered at all.

The present invention has been proposed in view of the above points, and an object thereof is to manage delivery confirmation as a multilink in an integrated manner, and all of the single links constituting the multilink move to a disconnection mode. It is to provide a delivery confirmation method capable of attempting recovery and ensuring delivery confirmation even when the delivery confirmation occurs.

[Means for Solving the Problems]

In order to achieve the above object, the present invention is a delivery confirmation method in a data link control procedure in a multilink environment, in which an information transfer dedicated frame including a transmission sequence number and a reception confirmation number as a frame transmitted and received on a multilink and a reception An order control that specifies a supervisory frame that includes a confirmation number, controls the order of frames to be sent and received and passes information to lower or upper layers, and sets a transmission sequence number and a reception confirmation number in the information transfer dedicated frame to be transmitted. Means, a response control means for setting a reception confirmation number in the monitoring frame and instructing transmission when there is no information transfer-dedicated frame for carrying a response to the received information transfer-dedicated frame, and a frame transmitted / received in the processing of the sequence control means Window control means for controlling the window of the When there is no response even after a lapse of a predetermined time from the transmission of the frame, error recovery means that tries to retransmit the unconfirmed information transfer dedicated frame up to a predetermined number of times, and the single link control for transmitting and receiving the frame is performed. A multilink management method that causes a single link that was disconnected during connection to be reconnected, and attempts to retransmit an unconfirmed information transfer dedicated frame to all connected single links after disconnecting all single links, and a single link And a single link control means for notifying the multilink management means of the connection / disconnection state of the above.

[Action]

In the delivery confirmation system of the present invention, the sequence control means controls the sequence of the frames to be transmitted and received and passes the information to the lower or upper layer, and sets the transmission sequence number and the reception confirmation number in the information transfer dedicated frame to be transmitted. If there is no information transfer-dedicated frame for carrying a response to the received information transfer-dedicated frame, the response control means sets a reception confirmation number in the monitoring frame to instruct transmission, and a window is sent for each frame transmitted / received during the processing of the sequence control means. The control means performs window control, and if there is no response after a lapse of a predetermined time from the transmission of the information transfer dedicated frame, the error recovery means retries a predetermined number of times for the unrecognized information transfer dedicated frame, and multi-link management Means controls the lower-level single link that transmits and receives frames, and Reconnect to the disconnected single link and try to retransmit the unconfirmed information transfer dedicated frame to all the connected single links after disconnecting all the single links. The state of connection / disconnection is notified to the multilink management means.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the delivery confirmation system of the present invention. In FIG. 1, this embodiment comprises a local station A, a partner station B, and a multilink 8 connecting both stations. In addition, the multi-link 8 is a plurality of single links 9
It consists of Further, F1 and F2 are frames transmitted and received on the multilink 8, and F1 is an information transfer including an information transfer dedicated frame identifier a, a transmission sequence number b, a reception confirmation number c, and information d as shown in FIG. Dedicated frame, F2 is the third
As shown in the figure, it is a supervisory frame including a supervisory frame identifier e and a reception confirmation number f.

On the other hand, the own station A and the partner station B have the same configuration with respect to the delivery confirmation function, and the sequence control means 1A and 1B and the response control means 2 are provided.
A, 2B, window control means 3A, 3B, and error recovery means 4A, 4B
And multi-link management means 5A, 5B, single-link control means 6A, 6B, and response waiting timers 7A, 7B. The function of each part will be described through the operation according to the flowcharts of FIGS.

The operation of the above embodiment will be described below. Note that the own station A will be described.

FIG. 4 is a flow chart showing the processing of the sequence control means 1A in FIG. In FIG. 4, the sequence control means 1A
In the case of transmission, the "command" is instructed to call the window control means 3A (step 101), and the window control means 3A
It is judged from the response returned from the device that the data can be transmitted (step 102). If the data can be transmitted (YES in step 102), the transmission sequence number and the reception confirmation number passed from the window control means 3A are sent to the information transfer dedicated frame F1. Set b and c in the table and start the response waiting timer 7A (step 10
3) The multilink management means 5A is requested to transmit the information transfer dedicated frame F1 (step 104), and the processing is terminated. If it cannot be sent (NO in step 102)
, The information transfer dedicated frame F1 is registered at the end of the transmission waiting queue (step 105), and the process ends.

On the other hand, in the case of reception, the window control means 3A is called by instructing "reception" (step 106) and it is discriminated whether the received frame is the information transfer dedicated frame F1 or the supervisory frame F2 (step 107). ). If the received frame is the information transfer dedicated frame F1 (YES in step 107), it is further determined whether reception is OK or reception is suspended (step 108),
If the reception is OK, the response transmission requirement is temporarily stored (step 109), and the received information transfer dedicated frame F1 is passed to the upper layer (step 110). If the reception is held pending (NO in step 108), the received information transfer dedicated frame F1 is once held (step 111). On the other hand, if the received frame is the supervisory frame F2 (N in step 107)
O) and after steps 110 and 111, proceed to step 112,
It is checked whether or not the information transfer dedicated frame F1 to be transmitted is registered in the transmission waiting queue (step 112). If it is registered (YES in step 112), the process proceeds to step 101. If it is not registered (NO in step 112), it is checked whether or not the response transmission requirement is stored (step 11).
3) If it is stored (YES in step 113), the response control means 2A is requested to send a response (step 114), and if it is not stored (NO in step 113), the process is not performed. finish.

FIG. 5 is a flow chart showing the processing of the response control means 2A in FIG. In FIG. 5, response control means 2A
When it is activated and starts processing, it acquires the current reception confirmation number from the window control means 3A (step 201), sets the acquired reception confirmation number in f in the monitoring frame F2 (step 202), and confirms the reception. The number is incremented by 1 (step 203), a transmission request is made to the multilink management means 5A (step 204), and the processing is ended.

FIG. 6 is a flow chart showing the processing of the window control means 3A in FIG. In FIG. 6, when the window control means 3A is activated and starts processing, it determines the received instruction (step 301). In the case of a transmission instruction (transmission in step 301), the current transmission sequence number is compared with the number confirmed for delivery (step 302), and it is determined whether the difference is within the transmission window size (step 303). When it is within the transmission window size (YES in step 303), 1 is added to the transmission sequence number to instruct "transmission is possible" (step
304), if the size exceeds the transmission window size, "not transmittable" is instructed (step 305), and the process ends.

On the other hand, in the case of the reception instruction (reception in step 301), the received frame is the information transfer dedicated frame F1 or the monitoring frame.
It is determined whether it is F2 (step 306) and the information transfer dedicated frame F
In the case of 1 (YES in step 306), the transmission sequence number b in the frame is compared with the reception confirmation number managed by the local station (step 307). Then, it is determined whether the difference is equal to or larger than the reception window size or double reception (step 30).
8) If so (YES in step 308), the received frame is discarded (step 312). However, the reception confirmation number included in the received frame is not discarded. Further, in the case of the normal information transfer dedicated frame F1 (NO in step 308), it is checked whether or not the above two numbers are equal (step 309), and if they are equal (YES in step 309).
"Reception OK" is instructed (step 310), and if they are not equal (NO in step 309), "reception hold" is instructed as prior reception (step 311).

When the frame received in step 306 is the supervisory frame F2 and after steps 312, 310, 311 the process proceeds to step 313, and the reception confirmation number c in the received information transfer dedicated frame F1 or f in the case of the supervisory frame F2 is acquired (step 313), the transmission order number for which the delivery confirmation from the own station has not been obtained with the reception confirmation number is checked and updated if necessary (step 314), and if all the delivery confirmations have been obtained, the response waiting timer is stopped ( (Step 315), the process ends.

FIG. 7 is a flow chart showing the processing of the error recovery means 4A in FIG. In FIG. 7, error recovery means 4A
Is activated when the response waiting timer 7A times out and starts processing. As the processing, the number of retransmissions is incremented by 1 (step 401), and then compared with the specified number of times (step 402), and if the specified number of times is exceeded (NO in step 402), it is judged as a failure in the partner station (step 404). ), The processing ends.
If the number of times is less than the specified number (YES in step 402), the order control means 1A is requested to perform transmission to correct the transmission window and retransmit it (step 403).

FIG. 8 is a flow chart showing the processing of the multi-link management means 5A in FIG. In FIG. 8, in the case of transmission, the multilink management means 5A searches for a single link 9 that can be transmitted (step 501), judges whether it has been found (step 502), and if found (step 5).
If YES in 02), the single link is requested to be transmitted (step 503), and the process ends. Also, if it is not found (NO in step 502), the transmission is OK (step 504). That is, there is no way to deal with a transmission NG, so the transmission is OK, and since there is no response from the other party, the transmission is dealt with again.

In the case of reception, the received frame is handed over to the sequence control means 1A (step 505), and the processing is ended. In the case of the processing disconnection notification, it is determined whether or not the multilink 8 is connected (step 506), and if it is connected (YE of step 506).
S) is instructed to start the reconnection procedure for the single link (step 507), and the process ends. If not connected, it is ignored and the process ends.

In the case of a single link connection notification, it is determined whether or not all other single links are disconnected (step 508), and if disconnected (YES in step 508), the transmission window is corrected and the sequence control means 1A is informed. The transmission (retransmission) of the information transfer dedicated frame F1 is requested (step 509), and the processing is ended. If there is another single link connected (step 508)
No) does nothing and ends the process.

FIG. 9 is a flow chart showing the processing of the single link control means 6A in FIG. In FIG. 9, the single link control means 6A gives a connection notification to the multilink management means 5A when the connection is completed (step 601), and gives a disconnection notification to the multilink management means 5A when the disconnection is completed ( Step 602), and the processing ends.

〔The invention's effect〕

As described above, in the delivery confirmation system of the present invention,
The delivery confirmation is managed comprehensively on the multi-link, and if the response is not received within the predetermined time, the re-transmission is attempted, and if all the single-links go into the disconnection mode, the re-connection of the single-link is attempted. Since a single link can be connected within the permissible time without disconnecting the multilink, the failure frequency is significantly reduced, and effective delivery confirmation can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the delivery confirmation system of the present invention, FIG. 2 is a logical block diagram of an information transfer dedicated frame, FIG. 3 is a logical block diagram of a supervisory frame, and FIG. Flow chart of processing of control means, FIG. 5 is a flow chart of processing of response control means, FIG. 6 is a flow chart of processing of window control means, FIG. 7 is a flow chart of processing of error recovery means, and FIG. 8 is multilink management. FIG. 9 is a flowchart of the processing of the means, and FIG. 9 is a flowchart of the processing of the single link control means. In the figure, A: own station B: partner station 1A, 1B ... sequence control means 2A, 2B ... response control means 3A, 3B ... window control means 4A, 4B ... error recovery means 5A, 5B. Multi-link management means 6A, 6B ... single-link control means 7A, 7B ... response waiting timer 8 ... multi-link 9 ... single-link F1 ... information transfer dedicated frame F2 ... monitoring frame

Claims (1)

[Claims] 1. In a delivery confirmation method in a data link control procedure in a multilink environment, a frame including an information transfer dedicated frame including a transmission sequence number and a reception confirmation number and a reception confirmation number as a frame transmitted and received on the multilink. The frame and the order control means for controlling the order of the frames to be transmitted and received to pass the information to the lower or upper layer, and setting the transmission sequence number and the reception confirmation number in the information transfer dedicated frame to be transmitted, and the received information. A response control means for setting a reception confirmation number in the monitoring frame and instructing transmission when there is no information transfer dedicated frame for carrying a response to the transfer dedicated frame, and a window for performing window control of the frame to be transmitted / received during the processing of the sequence control means. Control means and a predetermined time after the transmission of the information transfer dedicated frame Even if there is no response even if there is no response, the error recovery means that tries to retransmit the information transfer-dedicated frame that has not been confirmed up to a predetermined number of times, and the single link control that transmits and receives the frame is performed. A multilink management method that causes the link to reconnect and attempts to retransmit an unconfirmed information transfer dedicated frame to all connected single links after disconnection of all single links, and connection / disconnection of single links A delivery confirmation method, comprising: a single link control means for notifying the status to the multilink management means.