JPH053498A - Inactivity monitor method - Google Patents

Abstract

PURPOSE:To reply the early recovery of a resource quickly by revising an inactivity monitor time of a watchdog timer in response to a fault of a communication line. CONSTITUTION:When a reply of disable reception comes from a sender side in the step 3 during normal transmission reception, a receiver side sets a prescribed inactivity monitor time T2 sufficiently shorter than a normal time to a watchdog timer. The sender withdraws data transmission and is in standby of a reply from the receiver side. Then the receiver side checks its resource after elapse of the monitor time T2 to execute a reply and repeats the processing above till a credit value in the step S7 is recovered. When the resource is recovered in the step S7, the receiver side sends information to the sender side and the sender side restarts data transmission. Thus, when the resource is recovered early, the transmission reception is restarted quickly and the waiting time of the sender side is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inactivity monitoring method in which a receiving side monitors the inactive state of a transmitting side and makes a predetermined response.

[0002]

2. Description of the Related Art For example, in the data communication of the OSI transport layer protocol specification, communication is performed by repeating the operation of transmitting data to the receiving side within a data receiving allowable amount range notified from the receiving side to the transmitting side each time. Is done. In the class 4 of this protocol specification, there is a stipulation for network failure recovery.

FIG. 2 shows a sequence chart of a conventional inactivity monitoring method including such a failure recovery process.
The figure shows a sequence in which data communication based on the protocol specifications described above is performed between the transport entities on the transmission side and the reception side. First, data (DT-TPDU) is transmitted from the transmitting side in step S1. The receiving side receives this and executes a predetermined process, and at the same time, the next data reception allowable amount (credit value: C
A response including information indicating DT) is returned to the transmitting side (step S2).

That is, as shown in step S2, a response (AK
-TPDU) includes the credit value which is the reception allowable amount that can be received next time. This credit value is 0,
, 1, 2, ..., When the credit value is 1, it means that one (DT-TPDU unit) data can be received. The transmission side receives this and transmits the next data to the reception side within the allowable amount range (step S3).

Here, for example, if some trouble occurs in the communication line connecting the transmitting side and the receiving side, the data transmission in step S3 from the transmitting side to the receiving side will not be performed. On the receiving side, if no data is received from the transmitting side for a certain period of time, a predetermined failure occurrence process is performed assuming that a connection failure has occurred. The fixed time until the failure occurrence process is called the inactivity monitoring time (inactivity window timer). In order not to time out this inactivity window timer, AK is set at an interval that does not exceed the inactivity window timer. -Transmit TPDU. The time for transmitting this AK-TPDU, that is, the timer for measuring the inactivity window timer, is simply called a monitoring timer (window timer), and this window timer measures the time each time AK-TPDU is transmitted. Be started.

[0006] In this protocol, connection release processing for disconnecting the transmission side and reception side lines is performed.
When predetermined data is received by the receiving side as shown in step S3 in FIG. 2, the receiving side returns a response including information indicating the next data reception allowable amount to the transmitting side (step S4). , As in the case of step S2, the clocking of the monitoring timer is started.

FIG. 3 shows a flow chart of such a conventional monitoring operation. First, when a response is made in step S1, the inactivity monitoring time (inactivity window timer) T is set in step S2. Then, in step S3, the time counting by the monitoring timer is started.
The steps S1, S2 and S3 are executed almost at the same time. Then, after that, the state of waiting for the data reception from the transmitting side is waited, but at that time, it is judged whether or not a time-out occurs (step S4). If the data is received before the timeout occurs, the process proceeds to step S5 and the normal process is executed. On the other hand, when the time-out occurs, the process proceeds from step S4 to step S6, and the failure occurrence process, that is, the connection release is executed.

Here, at the time of the response from the receiving side to the transmitting side as described above, there may be a case where the next data reception allowable amount (credit value) is 0, that is, a response indicating that data reception is impossible. This is due to lack of resources on the receiving side,
After waiting for the recovery of resources, it will send a response to the sender again.

Such an operation sequence is shown after step S5 in FIG. In FIG. 2, when data is received from the transmitting side to the receiving side in step S5, and the receiving side responds with a credit value “0” in step S6, the previously used monitoring timer is restarted and the inactivity monitoring time is set. Time T. And when this monitoring timer times out (for example, after 70 seconds),
The state of the resource is checked again on the receiving side and a response is sent to the transmitting side (step S7).

In this case, since the credit value has been recovered to 2 in the example of the figure, the next data is transmitted from the transmitting side (step S8). When the receiving side replies to the transmitting side with a credit value of 0 as described above, the transmitting side waits until the next response is made and does not perform data transmission during that time. The procedure of steps S8 and S9 is shown in FIG.
The procedure is the same as steps S1 and S2.

[0011]

By the way, when a response indicating that data reception is impossible is made from the transmitting side in the above conventional method, the response interval is the inactivity monitoring time T (70 seconds) at which the monitoring timer times out. Every time. Further, the resources may be recovered before the inactivity monitoring time T elapses. However, in the conventional method, after receiving the response that the data cannot be received, the transmission must always be stopped and waited for the time T. This has a problem of hindering communication efficiency. The present invention has been made in view of the above points, and when the response from the transmission side prohibits data reception, if the resource is recovered early, the inactivity monitoring time of the monitoring timer is changed. By doing so, it is an object of the present invention to provide an inactivity monitoring method capable of returning a response at an early stage.

[0012]

According to the inactivity monitoring method of the present invention, data is transmitted while repeating the operation of transmitting data to the receiving side within the allowable data receiving amount range notified from the receiving side to the transmitting side each time. In communication, after receiving data from the transmission side, a response including information indicating the next data reception allowable amount is returned to the transmission side, and after the response, a first preset by a monitoring timer is set. When the inactivity monitoring time is measured and a response that allows the reception of a predetermined amount of data from the transmission side is made, failure occurrence processing is executed by the timeout of the monitoring timer, and data reception from the transmission side is performed. When making a response that prohibits, when the setting is changed to a second inactivity monitoring time shorter than the first inactivity monitoring time of the monitoring timer, and the monitoring timer times out, It is characterized in that the control to return a response including information indicating the degree data reception allowable amount to the transmitting side.

[0013]

According to this method, the receiving side sets the first inactivity monitoring time T1 as the inactivity monitoring time for monitoring until the data is received from the transmitting side, while the data from the transmitting side is set. When a response indicating that reception is impossible is made, the setting is changed to the second inactivity monitoring time T2 shorter than the first inactivity monitoring time T1. Then, a response is returned from the receiving side to the transmitting side until data can be received in the second inactivity monitoring time T2. As a result, the data can be transmitted from the transmitting side as soon as the resources are recovered.

[0014]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a sequence chart of the inactivity monitoring method of the present invention. In the figure, first, when the resources on the receiving side are not insufficient, the operation is similar to the conventional one. That is, when data (DT-TPDU) is received by the receiving side from the transmitting side in step S1, the receiving side transmits a response (AK-TPDU) (step S2). It should be noted that this response includes a credit value that is information indicating the next data reception allowable amount (simply called the allowable amount). In this example, the credit value is set to 3, and the data is sent from the transmitting side to the receiving side within the range of the credit value in step S3.

As described above, in the system in which the present invention operates, data communication is performed by repeating the operation of transmitting data to the receiving side within the allowable range notified from the receiving side to the transmitting side each time. Here, at the time of step S2 when the reception side responds to the transmission side, the monitoring timer is set to the first inactivity monitoring time (first inactivity window timer) T1 and inactivity monitoring is performed. The operation up to this point is no different from the conventional method. by the way,
When the receiving side sends a response to the transmitting side in step S4 after the receiving side receives predetermined data in step S3, the credit value is 0 here.

In other words, in this case, a response is sent from the transmitting side that the data cannot be received. Here, on the receiving side, the second inactivity monitoring time (second inactivity window timer) T2 is set for the monitoring timer. The second inactivity monitoring time T2 is set to a time sufficiently shorter than the first inactivity monitoring time T1. For example, in this embodiment, the first inactivity monitoring time T1 is set to 70 seconds and the second inactivity monitoring time T2 is set to 2 seconds. When the credit value is 0 and a response is sent to the transmitting side in step S4, the transmitting side suspends data transmission and waits for the next response from the receiving side. On the receiving side, the second inactivity monitoring time T
When 2 has elapsed, the resource is checked again and a response is executed (step S5).

In this example, the credit value is also 0 in the response in step S5. Therefore, the transmission side again suspends data transmission. Then, when the monitoring timer is started again and the second inactivity monitoring time T2 has elapsed,
A response is made again from the receiving side to the transmitting side (step S6). Also in this case, the credit value is 0, and the second inactivity monitoring time T2 is measured again. Next, when the response of step S7 is performed, the credit value is 3
Has recovered. Therefore, when the response including the information to that effect is transmitted to the transmitting side, the transmitting side transmits data corresponding to the credit value toward the receiving side (step S8).
After that, the same operation as described in steps S1 and S2 is repeated, the monitoring timer in which the first inactivity monitoring time T1 is set is started, and a predetermined response is given from the receiving side (step S9).

FIG. 4 shows a monitoring operation flowchart for organizing and explaining the operation of the present invention. Step S in the figure
When the above-described response is performed from the receiving side in 1, the first step is to determine in step S2 whether the allowable amount (credit value) is 0 or not. And the credit value is 0
If not, the normal processing is performed and the monitoring timer is set to the first
The inactivity monitoring time T1 is set (step S3).
Then, the monitoring timer starts counting (step S
5) After that, it is judged whether or not the time is out (step S6). Then, if the timeout has not occurred, normal processing is performed (step S7), and if the timeout has occurred, failure generation processing is performed (step S8). The processing in steps S6, S7 and S8 is exactly the same as that already described in steps S4, S5 and S6 in FIG.

On the other hand, in the case of the method of the present invention, when the credit value is judged to be 0 in step S2,
In step S4, the second inactivity monitoring time T2 is set. As a result, the sequence from step S4 to step S7 described in FIG. 1 is executed.

The present invention is not limited to the above embodiments.
Although the network failure recovery processing of the OSI transport layer protocol specification has been described in the above embodiment, the same applies to a system in which the receiving side monitors the inactive state of the transmitting side and executes a predetermined process in that state. Applied.

[0021]

According to the inactivity monitoring method of the present invention described above, the monitoring timer sets the first inactivity monitoring time T1 for inactivity monitoring on the transmitting side, and disables data reception. When the response is made, the second inactivity monitoring time T2 is set to shorten the transmission waiting time on the transmitting side. As a result, when the resources are recovered early, the transmitting side can be started promptly and the waiting time of the transmitting side can be shortened.

[Brief description of drawings]

FIG. 1 is a sequence chart of an inactivity monitoring method of the present invention.

FIG. 2 is a sequence chart of a conventional inactivity monitoring method.

FIG. 3 is a conventional monitoring operation flowchart.

FIG. 4 is a monitoring operation flowchart of the present invention.

[Explanation of symbols]

S1 to S9 Sequence of the present invention T1 First inactivity monitoring time (first inactivity window timer) T2 Second inactivity monitoring time (second inactivity window timer)

Claims (1)

Claim: What is claimed is: 1. A device for performing data communication while repeating an operation of transmitting data to a receiving side within a data receiving allowable amount range notified from the receiving side to the transmitting side each time. After receiving the data from the communication side, a response including information indicating the next data reception allowable amount is returned to the transmission side, and after the response, the first inactivity monitoring time preset by the monitoring timer is measured. Then, when a response permitting the reception of a predetermined amount of data from the transmitting side is made, a failure occurrence process is executed due to a timeout of the monitoring timer, and a response is made that data reception from the transmitting side is impossible. In this case, when the setting is changed to the second inactivity monitoring time shorter than the first inactivity monitoring time of the monitoring timer, and the monitoring timer times out, the allowable data reception amount is set again. Inactivity monitoring method and controlling to return a response containing to information on the transmitting side.