JPH0797781B2 - Priority control protocol conversion method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a priority control protocol conversion system, and in particular,
In a system in which a plurality of terminal devices connected to an ISDN network (integrated digital service network) and a host computer are coupled via a protocol conversion device, an inter-terminal communication protocol between the plurality of terminal devices and each terminal device The present invention relates to a priority control protocol conversion method in which a protocol conversion process for converting a host communication protocol between a host computer and a host computer is performed according to the priority order of the variable priority set corresponding to each terminal device.

[Conventional technology]

In a system in which a plurality of terminal devices connected to a network and a host computer are connected via a protocol conversion device, in a one-to-many protocol conversion device for converting between a host communication protocol and an inter-terminal communication protocol, , Priority control of protocol conversion may be required. In this case, for example, when the transmission requests from a plurality of terminal devices occur simultaneously, the priority order is set in advance for the terminal devices, and the transmission requests from a plurality of terminal devices occur at the same time. Sometimes
The transmission request is processed based on the priority of each terminal device. Here, even if the priority is set for each terminal device, the transmission request from the terminal device that first generated the transmission request is accepted first and processed first, so the terminal device with the lower priority When the transmission request from the terminal device is being processed, there is a problem that the transmission request from the terminal device having a high priority is not accepted and the transmission request is waited from the terminal device having a high priority.

In response to this, as described in Japanese Patent Application Laid-Open No. 61-10348, in a protocol conversion device that receives data from each terminal device and sends it to a host device in packet units, the data received from the terminal device is There is a proposal of a protocol conversion method which edits in packet units, determines the transmission order of data in packet units based on the priority order of terminal devices, and performs priority control by transmitting the data to a higher-level device. In this protocol conversion method, the memory queue for registering packetized data is changed according to the priority of each terminal device, and the data registered in the memory queue with a high priority is transmitted to the host device to perform priority control. The priority order corresponding to each terminal device here is fixed.

[Problems to be solved by the invention]

By the way, in the above-mentioned protocol conversion method, the priority corresponding to each terminal device is, for example, fixedly determined when the terminal device is installed, and the priority of each terminal device is fixed. Has become. For this reason, if priorities are determined when the terminal device is installed, the priorities will be fixed thereafter.

However, in the actual operation of the system, changes in the business form,
In many cases, it is desired to change the priority of each terminal device of the system connected to the system by the network regularly or irregularly in response to the personnel movement. Moreover, since the congestion distribution of the usage status of each terminal device changes depending on the time zone, it is often desired to change the priority depending on the time zone even during the operation of the protocol conversion device. Further, in order to secure the communication path from the specific terminal device to the host computer in the event of a sudden occurrence, it may be desired to raise the priority of the specific terminal device for a short time during the operation of the protocol conversion device.
In this way, considering the operation of the system, it is desirable to make the priority of each terminal device variable in order to flexibly deal with various cases.

An object of the present invention is to provide a priority control protocol conversion method capable of dynamically changing the priority of each terminal device even during operation of the protocol conversion device in order to flexibly deal with system operation.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

In order to achieve the above object, in the present invention, in a system in which a plurality of terminal devices connected to an ISDN network and a host computer are coupled via a protocol conversion device, a protocol conversion device, a plurality of each terminal device The terminal device is provided with a priority table for correspondingly setting the priority, and a priority control means for performing priority control of the protocol conversion processing based on the priority of each terminal device set in the priority table.
It is possible to change the priority of the priority table using the control information transfer channel of the ISDN network and to perform the protocol conversion process between each terminal device and the host computer according to the priority order of the priority set in the priority table. Characterize.

[Action]

According to the means, in the protocol conversion device that couples a plurality of terminal devices connected to the ISDN network and the host computer, a priority table for setting the priority corresponding to each of the plurality of terminal devices, and the priority table. Priority control means for performing priority control of the protocol conversion processing based on the priority of each terminal device set in the table is provided. The priority of each terminal device in the priority table is changed data from the terminal device using the control information transfer channel (hereinafter referred to as D channel) of the ISDN network connecting the protocol conversion device and each terminal device. Give and change. For example, from a predetermined terminal device to the ISDN network D
When the priority change notification is transmitted to the protocol conversion device using the channel, the protocol conversion device changes the priority of the corresponding terminal device in the priority table by the priority change notification, and the subsequent protocol conversion process is changed. Perform according to priority.

Since the priority of each terminal device is usually invariable for a certain period of time, the protocol conversion device immediately sets the priority set in the priority table of each terminal device at the time immediately before the stop, to a nonvolatile memory such as a magnetic disk device. When it is activated next time, the priority information of each terminal device is read out and the protocol conversion process is performed with the same priority as before.

In this way, in the protocol conversion device that performs protocol conversion from each terminal device, the priority of each terminal device can be dynamically changed by using the D channel of the ISDN network during its operation. Therefore, when the priority is changed regularly due to changes in the business form, personnel changes, etc., for example, each terminal device program sends a priority change notification at regular intervals and the priority of the priority table is changed. To change. When the protocol conversion device receives the priority change notification, the protocol conversion device changes the priority of the priority table, and performs the protocol conversion process with the notified priority until the next priority change notification is received. In addition, in order to cope with changes in the congestion distribution of usage conditions depending on the time of day,
When changing the priority of each terminal device according to the time zone,
The same process as above may be performed at regular intervals. When giving a high priority to a specific terminal device when an unexpected situation occurs, the priority change notification may be transmitted from the specific terminal device to the protocol conversion device by an operator operation.

Since this priority change notification is transferred by the D channel, which is a channel for control information transfer, which is different from the data transfer channel of the ISDN network (hereinafter referred to as B channel), data traffic for normal data communication is transmitted. Does not affect.

〔Example〕

An embodiment of the present invention will be specifically described below with reference to the drawings.

In all the drawings for explaining the embodiments, parts having the same function are designated by the same reference numerals, and repeated description thereof will be omitted.

FIG. 1 is a system configuration diagram according to an embodiment of the present invention. In FIG. 1, 1 is a protocol conversion device, 2 is a host computer, 3a, 3b and 3c are terminal devices, and 4 is an ISDN network. Each terminal device 3a, 3b, 3c is mutually connected by an ISDN network 4, and a host computer 2 is connected to this ISDN network 4 via a protocol conversion device 1 to form a system. The protocol conversion device 1 is a protocol conversion between a host-to-host communication protocol between the host computer 2 and a terminal-to-terminal communication protocol among the terminal devices 3a, 3b, 3c mutually connected by the ISDN network 4. Process. Each of the terminal devices 3a, 3b, 3c and the protocol conversion device 1 connected to the ISDN network 4 has its own terminal address TA within the ISDN network 4. For example, the terminal address of the protocol conversion device 1
TA is 0, terminal address TA of terminal device 3a is 1, terminal device 3b
Has a terminal address TA of 2 and the terminal device 3a has a terminal address TA of 3, and each of the terminal devices 3a, 3b, 3c and the protocol conversion device 1 designates a communication destination by the terminal address TA and transmits the transmission data. To the data transmission channel (B channel) of the ISDN network 4 to perform data communication between each terminal device or between the terminal device and the host computer.

FIG. 2 is a diagram showing a frame format of a priority change notification flowing through the D channel of the ISDN network 4. In FIG. 2, 21
Is a communication header DH for controlling the D channel of the ISDN network 4, and 22 is a communication trailer for controlling the D channel of the ISDN network 4.
It is DT. Further, 23 is an address field of the terminal address TA of the terminal device that transmitted the priority change notification.
For example, when the terminal device 3a sends the priority change notification, 1 is set in the address field 23 of the terminal address TA, and when the terminal device 3b sends the priority change notification, 2 is set in the address field 23. Is set. Reference numeral 24 is a priority field of priority P set corresponding to the terminal device that has transmitted the priority change notification. In this embodiment, the priority level P can be set to 1 or 2. Therefore, 1 or 2 is set in the priority field 24 for setting the priority.

FIG. 3 is a block diagram showing the configuration of the protocol conversion device 1. In FIG. 3, 31 is a B channel control unit that controls transmission on the B channel of the ISDN network, and 32 is a D channel control unit that controls transmission on the D channel of the ISDN network. The B channel control unit 31 and the D channel control unit 32 are configured by a processing device that controls communication and a control program that controls the processing device. Reference numeral 33 is a line control unit (LC) that performs line control with the host computer. The line controller 33 includes a processing device that controls communication and a control program that controls the processing device. 34 is a protocol conversion control unit,
It is composed of a protocol conversion unit a for converting the communication protocol for host to the communication protocol for terminals and a protocol conversion unit b for converting the communication protocol for terminals to the communication protocol for hosts. Reference numeral 35 denotes a central control unit that controls the entire protocol conversion device 1. The protocol conversion unit control 34 and the central control unit 35 are composed of a processing device and a control program for controlling the processing device. Reference numeral 36 is a priority table memory (PM) for storing the priority P set for the terminal device connected to the ISDN network 4. The priority table memory 36 is composed of an independent storage device, but may be provided in a memory in the processing device of the central control unit 35. Priority P set in the priority table memory 36
In this example, there are two levels, 1 and 2, and the priority part P is 2
The terminal device set to No. 2 provides twice as much service as the terminal device whose priority P is set to 1. Reference numeral 37 is a magnetic disk device, and 38 is a magnetic disk control unit. The magnetic disk device 37 is connected to the central control unit 35 via the magnetic disk control unit 38 and saves and stores the data of the priority P stored in the priority table when the power is turned off. That is,
The central control unit 35 stores the priority P of each terminal device set in the priority table at that time immediately before the stop in the magnetic disk device 37, and at the next startup, the stored priority P of each terminal device. Data is read out and protocol conversion processing is performed with the same priority P as before.

A wait queue LQ1 and a wait queue LQ2 are provided between the line control unit 33 and the protocol conversion control unit 34 to hold data waiting for protocol conversion processing when data is transmitted from the host computer side to the terminal device side. Is provided. Waiting queue
LQ1 is a waiting queue for holding data for the terminal device having the priority P of 1. The waiting queue LQ2 is a waiting queue for holding the data for the terminal device having the priority of 2. Also, the B channel control unit 31 and the protocol conversion control unit
A wait queue BQ1 and a wait queue BQ2 are provided between 34 to hold data waiting for protocol conversion processing when data is transmitted from the terminal device side to the host computer side. The waiting queue BQ1 is a waiting queue for holding the data coming from the terminal device having the priority P of 1. The waiting queue BQ2 is a waiting queue for holding the data coming from the terminal device having the priority P of 2.

FIG. 4 is a diagram showing a priority table set in the priority table memory 36. In this priority table, since the priority is set corresponding to each terminal device,
As shown in the figure, the terminal address TA and the priority P of each terminal device are set in association with each other.

Next, the operation of the protocol conversion device thus configured will be described.

[Operation at Startup] In the protocol conversion device 1, the central control unit 35 is started at startup.
Controls the magnetic disk device 37 by the magnetic disk control unit 38, reads the data of the priority P of all the terminal devices stored in the magnetic disk device 37, and the data of the priority P is the terminal address of each terminal device. It is stored in the priority table memory 36 in association with TA.

[Operation at Stop] Conversely, at the time of stop, the central control unit 35 takes out the data of the priority P of all the terminal devices set in the priority table memory 36, and the magnetic disk control unit 38 drives the magnetic disk device. 37, and stores the data of the priority P of all the terminal devices in the magnetic disk device 37.

As a result, the protocol conversion device 1 can perform the protocol conversion process with the same priority as before when it is restarted after being stopped.

[Operation When Receiving Priority Change Notification] When a priority change notification is transmitted from a certain terminal device to the protocol conversion device 1 through the D channel of the ISDN network 4, in the protocol conversion device 1, the D channel control unit 32 Then, the D channel control unit 32 notifies the central control unit 35 of the priority change notification. The central control unit 35 controls the D channel control unit 32 to read the terminal address TA and the priority field 24 priority P of the address field 23 of the received priority change notification, and the contents of the priority table memory 36 of the priority table memory 36 according to their contents. Update the priority table.

As a result, the protocol conversion device 1 thereafter performs the protocol conversion process with the priority P of the newly updated priority table. For example, when the protocol conversion device 1 receives the priority change notification with the terminal address TA = 1 and the priority P = 2 from the terminal device 3a, the priority table shown in FIG. ,
The shelf of priority P corresponding to 1 of the shelf of the terminal address TA is updated from 1 to 2.

[Operation during Protocol Conversion Processing] Protocol conversion processing from the host computer to the terminal device is executed in the following procedure.

Upon receiving the transmission data from the host computer 2, the line control unit 33 refers to the priority table data in the priority table memory 36 from the destination terminal address of the transmission data,
The priority P is checked, and the transmission data is put into the waiting queue LQ1 or LQ2 corresponding to the priority P waiting for the protocol conversion processing. That is, when the priority P is 1, the wait queue LQ1
When the priority P is 2, the transmission data is put in the waiting queue LQ2. Then, the central control unit 35 is notified of the data reception. Upon receiving the data reception notification from the line control unit 33, the central control unit 35 takes out the transmission data from the waiting queue LQ1 or LQ2, and the protocol conversion unit a of the protocol conversion control unit 34 performs the protocol conversion process. In this processing, which of the waiting queues LQ1 and LQ2 is to be used to fetch the transmission data is processed according to the flowchart shown in FIG.

FIG. 5 is a flowchart showing an algorithm for extracting transmission data from the waiting queue LQ1 or LQ2 waiting for the protocol conversion process to the terminal device. This will be described with reference to FIG. In this process, first, in step 51, 0
A random number of 1 or less is generated and set as a variable X.
Next, in step 52, it is determined whether or not the variable X is 0 or more and 1/3 or less. If the variable X is 0 or more and 1/3 or less, step 53
In order to take out the transmission data for the terminal device having the priority P of 1, the waiting queue LQ1 is examined. In step 53, if the waiting queue LQL1 is not empty, the process proceeds to step 54 and the transmission data for the terminal device having the priority P of 1 is taken out from the waiting queue LQ1. Also, wait queue at step 53
If LQ1 is empty, the routine proceeds to step 56, where transmission data for the terminal device having the priority P of 2 is taken out from the waiting queue LQ2. On the other hand, in step 52, the generated random variable X is 1/3.
If it is larger than 1 and proceeds to step 55, the wait queue LQ2 is examined to take out the transmission data for the terminal device having the priority P of 2. In step 55, the waiting queue LQ2
Is not empty, the process proceeds to step 56, and the transmission data for the terminal device having the priority P of 2 is taken out from the waiting queue LQ2. If the wait queue LQ2 is empty in step 55,
Proceeding to step 54, the transmission data for the terminal of priority 1 is fetched from the waiting queue LQ1. Note that the processing of this algorithm is executed after receiving data from the host computer 2 and receiving a notification of data reception, so here it is assumed that one of the wait queues LQ1 or LQ2 is not empty. ing.

According to the processing of the algorithm shown in FIG. 5, the random number is 0.
Since the data is evenly distributed between 1 and 1, the transmission data destined for the terminal device having the priority P of 2 will be processed with twice the probability of the transmission data destined for the terminal device having the priority P of 1.

The central control unit 35 performs the processing of the algorithm shown in FIG.
When the transmission data is extracted from Q2, the transmission data is passed to the protocol conversion control unit 34, and the protocol conversion unit a executes the protocol conversion process. When the protocol conversion process is completed, the transmission data is passed to the B channel control unit 31 and transmitted to the corresponding terminal device.

Similarly, the protocol conversion process from the terminal device to the host computer is executed in the following procedure.

When the B channel control unit 31 receives the transmission data from the terminal device of the ISDN network,
The priority table data of the priority table memory 36 is referred to check the priority P of the terminal device, and the wait queue BQ1 or BQ2 corresponding to the priority P having the protocol conversion process.
Put the transmission data in. That is, when the priority P is 1, the transmission data is put in the waiting queue BQ1, and when the priority P is 2, the transmission data is put in the waiting queue BQ2. And the data reception is controlled by the central control unit.
Notify 35. When the central control unit 35 receives the data reception notification from the B channel control unit 31, it waits for the protocol conversion processing queue BQ1 based on the processing algorithm shown in FIG.
Alternatively, the transmission data is extracted from BQ2, and the protocol conversion unit b of the protocol conversion control unit 34 performs the protocol conversion process.

FIG. 6 is a flowchart showing an algorithm for extracting transmission data from the waiting queue BQ1 or BQ2 having a protocol conversion process to the host computer system. The algorithm shown in FIG. 6 is the same as the algorithm shown in FIG.
It is a modification of LQ2 to BQ2, and basically performs the same processing. To briefly explain with reference to FIG. 6, first, a random number of 0 to 1 is generated and set as a variable X (step 61), and it is determined whether or not the variable X is 0 or more and 1/3 or less. The judgment is made (step 62). Variable X is 0 or more 1/3
If the following is true, the transmission data is extracted from the waiting queue BQ1 corresponding to the priority P of 1. Therefore, the waiting queue BQ1 is checked (step 63). If the waiting queue BQ1 is not empty, the transmission data is extracted from the waiting queue BQ1. (Step 64).
If the waiting queue BQ1 is empty, the transmission data is taken out from the waiting queue BQ2 (step 66). On the other hand, the variable X is 0 or more
Wait queue B corresponding to priority P of 2 unless 1/3 or less
To retrieve the transmission data from Q2, check the wait queue BQ2 (step 65), and if the wait queue BQ2 is not empty,
Retrieve the transmission data from the wait queue BQ2 (step 6
6) If the queue BQ2 is empty, the transmission data is fetched from the waiting queue BQ1 (step 64).

According to the processing of the algorithm shown in FIG. 6, the random number is 0.
Since the data is evenly distributed between 1 and 1, the transmission data from the terminal device with the priority P of 2 must be processed with twice the probability of the transmission data from the terminal device with the priority P of 1. become.

The central control unit 35 uses the algorithm shown in FIG. 6 to wait queue BQ1 or B waiting for protocol conversion processing.
When the transmission data is extracted from Q2, this transmission data is passed to the protocol conversion control unit 34, and the protocol conversion unit b of the protocol conversion control unit 34 executes the protocol conversion processing. When the protocol conversion process is completed, the data is passed to the line control unit 33 that controls the line to the host computer,
It is sent to the host computer 2.

As described above, according to the present embodiment, the priority of the protocol conversion process of each terminal device is not fixed, and the priority change notification is made by using the D channel of the ISDN network even during the protocol conversion process. Is sent to the protocol conversion process, and the priority P set corresponding to the terminal device can be changed, so that system operation can be dealt with flexibly. For example, (1) the priority can be changed periodically in response to a change in the business form, personnel movement, and the like.

(2) The priority can be changed depending on the time zone in response to changes in the congestion distribution depending on the time zone.

(3) The priority of a specific terminal device can be raised only for a short time in order to deal with an unexpected situation.

Since this priority changing process is performed using the D channel of the ISDN network, it does not adversely affect the normal data traffic using the B channel for data transmission.

The present invention has been specifically described above based on the embodiments,
It is needless to say that the present invention is not limited to the above-mentioned embodiments and can be variously modified without departing from the scope of the invention.

〔The invention's effect〕

As described above, according to the present invention, in the protocol conversion device, for example, even during the protocol conversion process, the priority set corresponding to the terminal device can be changed by using the D channel of the ISDN network. Therefore, the priority of the protocol conversion process of each terminal device is not fixed, and the system operation can be dealt with flexibly.

[Brief description of drawings]

FIG. 1 is a system configuration diagram according to an embodiment of the present invention, FIG. 2 is a diagram showing a frame format of a priority change notification flowing through a D channel of an ISDN network, and FIG. 3 is a configuration of a protocol conversion device. FIG. 4 shows a priority table set in a priority table memory, and FIG. 5 shows an algorithm for extracting transmission data from a waiting queue waiting for protocol conversion processing to a terminal device. A flowchart, FIG. 6 is a flowchart showing an algorithm for extracting transmission data from a waiting queue having a protocol conversion process to the host computer. 1 ... Protocol conversion device, 2 ... Host computer, 3a, 3
b, 3c ... Terminal device, 4 ... ISDN network, 31 ... B channel control unit, 32 ... D channel control unit, 33 ... Line control unit, 34
...... Protocol conversion control unit, 35 ...... Central control unit, 36 ......
Priority table memory, 37 ... Magnetic disk unit, 38 ...
… Magnetic disk controller.

Claims (1)

[Claims] 1. In a system in which a plurality of terminal devices connected to an ISDN network and a host computer are connected via a protocol conversion device, a priority is set in the protocol conversion device corresponding to each of the plurality of terminal devices. And a priority control means for performing priority control of protocol conversion processing based on the priority of each terminal device set in the priority table, and the terminal device is provided with a control information transfer channel of the ISDN network. A priority control protocol conversion method characterized in that the priority of the priority table is changed by using the priority table, and the protocol conversion process between each terminal device and the host computer is performed according to the priority order of the priority set in the priority table.