JP3036546B2 - Dedicated line backup method and system - Google Patents

Description

The present invention relates to a method and a system for switching to a backup line in a data communication network using a dedicated line.

2. Description of the Related Art In general, in a data communication network that communicates between two points using a dedicated line, a dial backup device that switches the dedicated line to a telephone public line when a failure occurs between the two points is used. .

FIG. 1 is a block diagram showing a configuration of a conventional data communication network in a case where communication is performed between two points using one dedicated line.

In FIG. 1, 1 is a host computer, 2 is a data terminal, 3 is a modem, 4 is a dial backup device, 5
Is an exclusive line, 6 is a telephone public line, and 7 is a telephone public line switch.

FIG. 2 shows a procedure for switching to the telephone public line 6 between two points, that is, when the dedicated line 5 fails.

The host computer 1 periodically sends inquiry information to the data terminal 2 to check whether data communication with the data terminal 2 is normally performed.
In response to the inquiry information, polling confirmation that response information is returned to the host computer 1 is performed. That is, the host computer 1 receives the response information within a certain time after transmitting the inquiry information,
It can be confirmed that data communication with the data terminal 2 is normally performed.

When a failure occurs in the leased line 5, the host computer 1
Since the response information cannot be received, the occurrence of the failure is detected, and the maintenance person is notified of the failure.

Then, the maintenance person dials the dial backup device 4 of the host computer 1 and calls the dial backup device 4 of the data terminal 2 via the telephone public line 6.

The dial backup device 4 on the data terminal 2 side
When called, it responds immediately and switches the dedicated line 5 to the telephone public line 6. On the other hand, the dial
When the dial backup device 4 of the data terminal 2 responds, the backup device 4 switches the dedicated line 5 to the telephone public line 6.

Thereby, the host computer 1 and the data terminal 2
The host computer 1 is connected by the telephone public line 6
Polling between the terminal and the data terminal 2 is recovered, and the host computer 1 notifies the maintenance person of the failure recovery.

According to the above procedure, the maintenance person, after the failure of the dedicated line 5,
It can be confirmed that the switching to the telephone public line 6 has been completed.

[Problems to be Solved by the Invention] According to the above-mentioned conventional technology, in order to switch from a dedicated line to a telephone public line, a maintenance person specifies a corresponding dial / backup device based on a failure notification from a host computer and dials. There is an operational problem that the switching operation is complicated because the user has to perform the operation.

Further, in the above-mentioned prior art, since the switching from the dedicated line to the telephone public line is performed by a dial operation using the telephone public line, the dial-backup device on the receiving side does not respond when a call is made from the telephone public line. Incoming condition. For this reason, even if a general telephone performs a dial operation from a general telephone to the dial backup device, the call arrives at the dial backup device, and even if the dedicated line is not a failure, the line of the general telephone malfunctions. Is switched, there is a problem in network management.

An object of the present invention is to provide a dedicated line backup method and system in which an operation for switching from a dedicated line to a backup line is simple.

It is another object of the present invention to provide a dedicated line backup method and system which enable connection of specific backup devices when switching from a dedicated line to a backup line.

Means for Solving the Problems In order to achieve the above object, the present invention provides a backup device having a function of switching a dedicated line to a public line when a failure occurs between two points connected by the dedicated line. In the data communication network provided in the above, at the time of the above two points of failure,
From one of the two backup devices, via the public line that can transmit the telephone number of the own device when making a call,
Transmitting the response to the other one of the backup devices, returning a response from the backup device on the receiving side to the backup device on the transmitting side after receiving the transmission; Each of the two backup devices switches the dedicated line to the public line.

At this time, for the backup device on the transmitting side,
An instruction for designating the calling side and a telephone number of the backup device on the receiving side are given from the outside via the public line, and an instruction for designating the receiving side for the receiving device and calling are provided. The telephone number of the backup device on the side can be given externally via the public line.

Also, the backup device on the receiving side, upon receiving a call,
The telephone number of the transmitting apparatus transmitted by the public line is compared with the telephone number of the external backup apparatus given from the outside, and a response is returned if they match. .

In addition, the present invention includes a backup device provided at each of two points connected by a dedicated line and having a function of switching the dedicated line to a public line when a failure occurs between the two points. In the event of a failure, at least one network configuration management device having a function of transmitting a call to the two backup devices via the public line and transmitting a switching instruction to switch the dedicated line to the public line is provided. Offers a dedicated line backup system.

The network configuration management device determines whether there is a failure between the two points,
Storage means for storing at least the use status of the public line and the telephone number of each backup device, display means for displaying all or a part of the contents stored in the storage means, and an instruction for switching the dedicated line to the public line Receiving means for receiving the switching command by the receiving means, transmitting means for transmitting via the public line based on the telephone number of each backup device, and a response returned from the backup device. In this case, the backup device may include a switching instruction transmitting unit that transmits a switching instruction for switching the dedicated line to the public line.

The switching instruction transmitted by the switching instruction transmitting means is, for example, for one backup device, information indicating designation to the calling side and the telephone number of the backup device serving as the receiving side. For
This is information to be designated as the receiving side and the telephone number of the backup device which is the transmitting side.

Further, the transmitting means of the network configuration management device transmits the telephone number of the own device and transmits the telephone number to the backup device, and the backup device stores the telephone number of the network configuration management device registered in advance. Storage means, the telephone number of the network configuration management device stored in the storage means, and the telephone number of the network configuration management device transmitted from the network configuration management device, and when both match,
It may have a first matching means for returning a response.

Further, when the backup device receives, as the switching instruction, information indicating designation to the calling side and a telephone number of the backup device to be the receiving side, the backup device is configured based on the telephone number of the backup device to be the receiving side. A first transmitting means for transmitting and transmitting the telephone number of the own device via a public line, and, when a response is returned from the backup device on the receiving side, the dedicated line is switched to a public line. A first switching unit, and when the switch receives the information for designating the receiving side and the telephone number of the backup apparatus serving as the transmitting side, the switching is performed from the backup apparatus on the transmitting side. The telephone number is compared with the telephone number of the backup device on the transmitting side received as the switching instruction, and when both match, the backup device on the transmitting side is checked. It is possible to have a second matching means for returning an answer and a second switching means for switching the dedicated line to a public line when the two match by matching by the second matching means. .

Further, the backup device, based on the telephone number of the network configuration management device stored in advance, when the first switching unit or the second switching unit switches the dedicated line to a public line, A second transmitting means for transmitting via the public line, and a switching information transmitting means for transmitting information indicating that the dedicated line has been switched to the public line when a response is returned from the network configuration management device. Can be included.

In order to transmit the telephone number of the own device when making a call, for example, an ISDN public line can be used as the public line. In this case, the switching instruction is
The data is transmitted by being set to the D channel user part of the public line, and the backup device has means for multiplexing the data communication speed of the dedicated line to the standard speed of the ISDN public line. You can do so.

In the backup device, the first switching unit and the second switching unit are functionally different from each other, but hardware and software can be realized as common components. The same applies to the first transmitting means and the second transmitting means, as well as the first collating means and the second collating means.

[Operation] Hereinafter, the operation of the present invention will be specifically described.

For example, in a data terminal network in which a host computer and a data terminal are connected by a dedicated line, in a normal state, the storage contents of the storage means of the network configuration management device indicate that there is no failure and that there is no failure. The line usage status is “unused”. The telephone numbers of the respective backup devices and their contents are displayed by the display means.

Upon receiving the fault information from the host computer, the maintenance person checks the telephone number of the corresponding backup device by looking at the contents displayed on the network configuration management device, and inputs an instruction to switch the dedicated line to the public line.

In the network configuration management device, when the receiving unit receives the switching command, the transmitting unit transmits to the corresponding backup device, and the switching instruction transmitting unit transmits the switching instruction.

As a result, the maintenance person can omit the operation of specifying the corresponding backup device and performing the dial operation, thereby simplifying the switching operation.

Further, in the backup device, when an incoming call is received from the network configuration management device, the first collation unit compares the received telephone number of the network configuration management device with the telephone number of the network configuration management device stored in advance. If they match, a response is sent back; if they do not match, the call is rejected.

Thus, it is possible to reject an incoming call from an unauthorized device.

Further, in the backup device that receives the information to be designated as the calling side and the telephone number of the backup device as the receiving side as the switching instruction, the first transmitting means transmits the information to the backup device as the receiving side. send.

At this time, since the telephone number of the own device is also transmitted, the backup device that has received the information indicating the designation on the receiving side and the telephone number of the backup device on the transmitting side as the switching instruction, performs the second verification. Means for comparing the telephone number transmitted from the backup device on the transmitting side with the telephone number of the backup device on the transmitting side received as the switching instruction, and if they match, returns a response; Switches the private line to a public line. If they do not match, the call is rejected. In the backup device on the transmitting side that has received this response, the first switching means
Switch the leased line to the public line.

As a result, even on a public line, specific backup devices specified by the network configuration management device can be reliably connected.

In the backup device, when the dedicated line is switched to the public line, the second transmitting unit transmits to the network configuration management device, and the switching information transmitting unit switches the dedicated line to the public line. Send the information to the effect.

This allows the network configuration management device to manage the line status collectively.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 3 is a block diagram showing a configuration of a data communication network to which the first embodiment of the present invention is applied.

In FIG. 3, 1 is a host computer, 2 is a data terminal, 3 is a modem, 5 is a dedicated line, 8 is an ISDN backup device, 9 is a network configuration management device, 10 is an ISDN public line, and 11 is IS
It is a DN public line switch.

Fig. 4 shows that when a failure occurs in the leased line 5, the ISDN
A procedure for switching to the public line 10 will be described.

The host computer 1 periodically sends inquiry information to the data terminal 2 to confirm whether data communication with the data terminal 2 is normally performed. When the inquiry information is received, polling confirmation that response information is returned to the host computer 1 is performed. That is, after transmitting the inquiry information, the host computer 1 can confirm that the data communication with the data terminal 2 is normally performed by receiving the response information within a predetermined time.

When a failure occurs in the leased line 5, the host computer 1
Since the response information cannot be received, it is detected that a failure has occurred, and the maintenance person is notified of the failure.

 FIG. 5 (a) shows an example of a failure notification screen display.

In this embodiment, the host computer 1 assigns a line number to a route for performing polling confirmation, that is, a route (in this case, a dedicated line 5) connecting the host computer 1 and the data terminal 2. The screen display example in FIG. 5 (a) shows that the line number "1" is notified that a failure has occurred.

The maintenance person inputs the failure information notified from the host computer 1 to the network configuration management device 9. As an input example, the fifth
As shown in FIG. 6B, a line number ("1") is input.

The network configuration management device 9 refers to a table regarding the configuration of the data communication network stored in the internal storage device, and displays information such as the location and the telephone number of the corresponding ISDN backup device 8 on a screen.

FIG. 6 shows an example of a table relating to the configuration of the data communication network stored in a storage device inside the network configuration management device 9. FIG. 5 (c) shows a screen table of the network configuration management device 9. An example is shown.

In FIG. 6, this table contains the line numbers and their statuses managed by the host computer 1, the telephone number and location of the backup device 8 on the host computer 1, the telephone number and location of the backup device 8 on the data terminal 2 side,
The use status of the backup line (ISDN public line 10) corresponding to each dedicated line 5 is stored. The use status of the backup line is automatically updated by the network configuration management device 9. “Waiting for connection” indicates that the maintenance operator has instructed the switching, but the switching has not been completed yet. , “Failure” indicates that the switching has failed.

The maintenance person checks the display screen shown in FIG.
The switching command is input to the network configuration management device 9. The switching instruction is
This is performed by inputting the line selection number "2" on the display screen shown in FIG. 5 (c). Further, the maintenance person can also input a command “0” without switching (as is).

Upon input of the switching command from the maintenance person, the network configuration management device 9 changes the display of "dedicated line" to the display of "ISDN public line connected" as shown in FIG. Update the use status of the backup line in the table shown in the figure to “waiting for connection”. And one of the
A call is made to the ISDN backup device 8 via the ISDN public line 10.

When called by the network configuration management device 9, the ISDN backup device 8 queries the telephone number of the network configuration management device 9 registered in advance and the telephone number of the transmission source notified on the ISDN public line 10, If they match, answer the call; otherwise, reject the call.

It goes without saying that the ISDN public line 10 has the property of transmitting the telephone number of the caller to the receiver.

When the called ISDN backup device 8 responds, the network configuration management device 9 instructs the responding ISDN backup device 8 to designate it as the called side and the calling side, as shown in FIG. 7 (a). A switching instruction in which the telephone number of the ISDN backup device 8 is set is transmitted, and the ISDN public line 10 is disconnected.

Similarly, the network configuration management device 9 sends the other IS
A call is made to the DN backup device 8 via the ISDN public line 10.

When called from the network configuration management device 9, the ISDN backup device 8 collates the telephone number of the network configuration management device 9 registered in advance with the telephone number of the transmission source notified on the ISDN public line 10, If they match, answer the call; otherwise, reject the call.

When the called ISDN backup device 8 responds, the network configuration management device 9 instructs the responded ISDN backup device 8 to specify the designation on the calling side as shown in FIG. A switching instruction in which the telephone number of the ISDN backup device 8 is set is transmitted, and the ISDN public line 10 is disconnected.

Next, the ISDN backup device 8 designated for the calling side
Makes a call via the ISDN public line 10 based on the telephone number of the ISDN backup device 8 on the receiving side.
The called ISDN backup device 8 collates the telephone number of the calling ISDN backup device 8 transmitted from the network configuration management device 9 with the telephone number of the transmission source notified on the ISDN public line 10 and finds a match. If so, the call is answered and the dedicated line 5 is switched to the ISDN public line 10. If they do not match, the call is rejected.

When the called ISDN backup device 8 responds, the calling-side ISDN backup device 8 switches the dedicated line 5 to the ISDN public line 10.

According to the above procedure, the host computer 1 and the data terminal 2 are connected by the ISDN public line 10, so that the polling between the host computer 1 and the data terminal 2 is recovered, and the host computer 1 Notification of failure recovery.

 FIG. 5E shows an example of the screen display of the failure recovery notification.

Further, when the switching is completed, the ISDN backup devices 8 on the calling side and the called side respectively receive the network configuration management devices 9
Is called via the ISDN public line 10.
When the called network configuration management device 9 responds, the end of switching is transmitted as switching information, and the ISDN public line 10 is disconnected.

The network configuration management device 9 includes two ISDN backup devices 8
When the switching information is received from the server, the status of use of the backup line in the table stored in the internal storage device is updated from "waiting for connection" to "in use", and FIG.
The message "ISDN public line connected" shown in
By changing the display to "public line", the maintenance person is notified that the line switching has been completed.

If the switching is not completed within a predetermined time due to a failure of the ISDN backup device 8 or the like, the display is changed to "ISDN line failure".

By the above procedure, the maintenance person can receive the notification from both the host computer 1 and the network configuration management device 9 and can confirm that the switch to the ISDN public line 10 has occurred after the failure of the dedicated line 5.

 FIG. 8 shows a configuration example of the network configuration management device 9.

In FIG. 8, 81 is a display, 82 is a keyboard, 83 is a storage device, 84 is a microprocessor (MPU), 8
5 is an ISDN card, 86 is a B channel controller (LAP
B), 87 is a D channel controller (LAPD), 88 is ISDN
Interface circuit (INF).

As shown in FIG. 8, the network configuration management device 9 can be realized by a configuration in which an ISDN card 85 is added to a personal computer. The above-described table is stored in the storage device 83.

FIG. 9 (a) shows a configuration example of the ISDN backup device 8, and FIG. 9 (b) shows the appearance of the ISDN backup device 8.

In FIG. 9A, 90 is an electromagnetic contact, 91 is a liquid crystal display, 92 is a keypad, 93 is a memory, 94 is a microprocessor (MPU), 95 is a B-channel controller (LAP).
B), 96 is a D channel controller (LAPD), 97 is a data rate converter (RA), 98 is an ISDN interface circuit (IN
F).

Under normal conditions, the electromagnetic contact 90 is connected between a and b, and the host computer 1 and the modem 3 are connected. When a failure occurs in the leased line 5, the connection between a and c is established according to the above-described procedure, and the leased line 5 is switched to the ISDN public line 10.

The incoming request (call) from the network configuration management device 9 is an ISDN
Via the public line 10, the IN in the ISDN backup device 8
Entered in F98. The INF 98 extracts a D-channel signal from the multiplexed signal on the line and inputs it to the LAPD 96.
The LAPD 96 analyzes the ISDN message and notifies the MPU 94 that the incoming request has been received.

The MPU 94 collates the telephone number of the network configuration management device 9 registered in the memory 93 in advance with the telephone number of the caller included in the incoming call request, and if they match, permits the incoming call (call response). Will be returned. If they do not match, a call rejection is returned.

When the ISDN backup device 8 returns the incoming call permission, the network configuration management device 9 enters a communication state.

As a method of registering the telephone number of the network configuration management device 9 in the memory 93 of the ISDN backup device 8, for example,
As shown in FIG. 9 (c), the registration can be performed by dialing the keypad 92 in the same manner as the method of registering the speed dial on the telephone.

The switching instruction from the network configuration management device 9 is transmitted to the ISDN public line 10
Is input to the INF 98 in the ISDN backup device 8 via the. INF98 is B from the signal multiplexed on the line.
The channel signal is extracted and input to LAPB95. LAPB95
Analyzes the ISDN message and notifies the MPU 94 that the switching instruction has been received.

The MPU 94 sends a response to the switching instruction as LAPB95, INF98, IS
It is returned to the network configuration management device 9 via the DN public line 10.

When receiving the response to the switching instruction, the network configuration management device 9 transmits a disconnection to the ISDN backup device 8.

The disconnection from the network configuration management device 9 is notified to the MPU 94 on the same route as the incoming request. The MPU 94 returns a disconnection response on the same route as the incoming call permission, and releases the B2 channel.

Now, in the ISDN backup device 8 designated as the calling side in the switching instruction, the MPU 94 sends the LAPD96, INF98, ISDN public line 10 to the ISDN backup device 8 as the called side.
Send an incoming request via. And IS on the receiving side
When receiving the incoming call permission from the DN backup device 8, the B1 channel is released.

Next, the MPU 94 switches the electromagnetic contact 90 so that a-c is connected. Therefore, a data signal from the host computer 1 is input to the RA 97 via the electromagnetic contact 90. RA97
Converts the speed of the data signal to the ISDN standard speed of 64 kb / s and inputs it to INF98. The INF 98 inserts a 64 kb / s data signal into the B1 channel and sends it to the ISDN public line 10.

Similarly, the data signal of the receiving-side ISDN backup device 8 received from the ISDN public line 10 is input to the host computer 1 via the INF 98, the RA 97, and the electromagnetic contact 90.

Through the above operation, the ISDN backup device 8 switches to the ISDN public line 10 when the dedicated line 5 fails.

Although the B2 channel is used to communicate the switching instruction from the network configuration management device 9, the communication may be performed using the D channel user packet. At this time, since the function of LAPB95 is performed by LAPB96, LAPB95 can be deleted in ISDN backup device 8.

In the control of the electromagnetic contact 90, ab
The connection between the host computer 1 and the modem 3 can be maintained even when the power of the ISDN backup device 8 is turned off by using the electromagnetic contact 90 that operates so that the connection is established. it can.

FIG. 10 is a block diagram showing a configuration of a data communication network to which the second embodiment of the present invention is applied.

The data communication network in this embodiment has a configuration in which a host computer communicates with three data terminals via a relay point.

In FIG. 10, 1 is a host computer, 2a, 2b, 2c are data terminals at three points, 3 is a modem, 5a, 5b, 5c are dedicated lines, 810, 820, 830a, 830b, 830c are ISDN backup devices, and 9 is Network configuration management devices, 101, 102, 103a, 103b, 103c are IS
DN public line, 11 is an ISDN public line switch, 12 is a multiplexer, and 13 is a high-speed digital exclusive line.

Under normal conditions, the host computer 1 and the data terminal 2a are connected by the high-speed digital dedicated line 13 and the dedicated line 5a. Similarly, the host computer 1 and the data terminal 2b are connected by a high-speed digital dedicated line 13 and a dedicated line 5b, and the host computer 1 and the data terminal 2c are connected by a high-speed digital dedicated line 13 and a dedicated line. Connected by 5c.

First, a case where a failure occurs between the host computer 1 and the data terminal 2a will be described.

When polling cannot be confirmed between the host computer 1 and the data terminal 2a, first, the host computer 1 notifies a maintenance person of a failure.

In this embodiment, the host computer 1 uses a line number “1” for a route connecting the host computer 1 and the data terminal 2a, and a line number “2” for a route connecting the host computer 1 and the data terminal 2b. , Host computer 1 and data terminal 2c
Is managed as a line number “3”.

Therefore, the failure notification performed by the host computer 1 is a notification that the line number “1” is a failure, and the maintenance person inputs the failed line number (“1”) to the network configuration management device 9. I do.

In the network configuration management device 9, for example, assuming that the host computer 1 and the ISDN backup device 810 are in Tokyo, the ISDN backup device 820 is in Yokohama, and the ISDN backup device 830a is in Ofuna, a display as shown in FIG. Screen.

The cause of the failure between the host computer 1 and the data terminal 2a may be caused by the high-speed digital private line 13 (AB
Is a failure, the leased line 5a (between BC) is a failure, and the ISDN backup device 820 (point B)
Can be considered as a failure or a combination thereof. However, if the high-speed digital leased line 13 or the ISDN backup device 820 becomes a failure, the route connecting the host computer 1 and the data terminal 2b and the host Since the routes connecting the computer 1 and the data terminal 2c should simultaneously become obstacles, in this case, it can be seen that the dedicated line 5a is the obstacle.

Then, the maintenance person instructs to switch between B and C to the ISDN public line.

Therefore, similarly to the above-described procedure, the switching instruction is transmitted from the network configuration management device 9 to the corresponding ISDN backup devices 820, 830a. The ISDN backup devices 820, 830a switch to the ISDN public lines 102, 103a. As a result, the dedicated line 5a
Is switched to the ISDN public lines 102 and 103a.

In this way, the fault between the host computer 1 and the data terminal 2a is recovered. The same applies when a failure occurs between the host computer 1 and the data terminal 2b and when a failure occurs between the host computer 1 and the data terminal 2c.

Next, a case where a failure occurs between the host computer 1 and the data terminals 2a, 2b, 2c will be described.

When polling cannot be confirmed between the host computer 1 and the data terminals 2a, 2b, 2c, the host computer 1 first notifies a maintenance person of a failure. The maintenance person inputs the line numbers (“1”, “2”, “3”) of the fault to the network configuration management device 9.

In the network configuration management device 9, the display screen is as shown in FIG. 11 (b).

The cause of the failure between the host computer 1 and the data terminals 2a, 2b, 2c is the high-speed digital leased line 13 (A ₁
-B between _1, between A ₂ -B _2, and when A between ₃ -B ₃₎ is in a fault, among a dedicated line 5a (B ₁ -C), dedicated line 5b (B between ₂ -D), dedicated line 5c (between B _{3 and} E) is a failure, ISDN backup device 820 (B ₁ , B ₂ , B ₃ points) is a failure,
It is conceivable that these are combinations, but it is not possible to determine which one is only by this display screen.

Therefore, maintenance personnel, between A ₁ -B _1, between A ₂ -B _2, compared to between A ₃ -B _3, between B ₁ -C, between B ₂ -D, B ₃ -E between a short distance Yes, ISDN
First, since the telephone charges for public lines are low, first, between B _{1 and} C, B _2-
Command to switch between D and B ₃ -E to ISDN public line.

Therefore, similarly to the procedure described above, the leased line 5a is connected to the ISDN
The private lines are switched to the public lines 102 and 103a, the dedicated line 5b is switched to the ISDN public lines 102 and 103b, and the dedicated line 5c is switched to the ISDN public lines 102 and 103c.

If the failure between the host computer 1 and the data terminals 2a, 2b, 2c is due to a failure in the dedicated lines 5a, 5b, 5c, this is recovered.

If this in not recover failure, maintenance personnel, B ₁ -C between, B
Between ₂ -D, back between B ₃ -E dedicated line 5a, 5b, to 5c, A ₁ -B
Command to switch to ISDN public line between _{1 and} between A _{2 and} B _{2 and} between A _{3 and} B ₃ .

Therefore, similarly to the above-described procedure, the switching instruction is transmitted from the network configuration management device 9 to the corresponding ISDN backup devices 810 and 820. The ISDN backup devices 810 and 820 multiplex three data signals corresponding to the three data terminals 2a, 2b and 2c and switch to the ISDN public lines 101 and 102. As a result, the high-speed digital private line 13 is switched to the ISDN public lines 101 and 102.

If the failure between the host computer 1 and the data terminals 2a, 2b, 2c is due to the failure of the high-speed digital leased line 13,
This will recover. At this time, if a part of the failure between the host computer 1 and the data terminals 2a, 2b, 2c is not recovered, it is known that the corresponding dedicated line is also a failure, and the part is switched to the ISDN public line.

Also, the high-speed digital private line 13 is connected to the ISDN public line 101,
If the failure does not recover after switching to 102, the maintenance
It is determined that a failure has occurred in the SDN backup device 820, and A ₁
-B between _1, A ₂ -B between ₂ to disconnect the ISDN public line between A ₃ -B _3, A ₁
-C between, between A ₂ -D, commands to switch between the A ₃ -E in ISDN public line.

Therefore, similarly to the above-described procedure, the switching instruction is transmitted from the network configuration management device 9 to the corresponding ISDN backup devices 810, 830a, 830b, 830c. ISDN backup device 810,830
a, 830b, 830c are switched to ISDN public lines 101, 103a, 103b, 103c. The ISDN backup device 810 is an ISDN public line 101
The corresponding three data signals are transmitted to different B channels.

In addition, although it has been described that these operations are determined and performed by the maintenance person, they may be incorporated in the network configuration management device 9 as expert rules, and may be performed in an interactive manner with the maintenance person.

Also, the ISDN backup devices 830a and 830 in FIG.
b and 830c are the same as the configuration shown in FIG. 5, and the ISDN backup devices 810 and 820 have the configuration as shown in FIG. 12, respectively.

In FIG. 12, an ISDN backup device 810 includes a data multiplexing circuit (MPX) 812 that multiplexes a data communication speed between the host computer 1 and the data terminals 2a, 2b, 2c to an ISDN standard speed of 64 kb / s. Have.

The ISDN backup device 820 includes the MPX822 described above and a data selection circuit (SEL) 823 that selects one data signal from a plurality of data signals.

Although the ISDN backup devices 810 and 820 are not shown in the figure, it is assumed that all the circuits shown in FIG. 5 are provided.

When switching the dedicated line 5a to the ISDN public line 102, 103a, the ISDN backup device 820 switches the electromagnetic contact 821a, selects the data signal from the electromagnetic contact 821a with the SEL823, and, via the INF824, the ISDN public line 102, Connect with I
The SDN backup device 830a switches the electromagnetic contact 831 and outputs the IS
Connect to DN public line 103a.

Also, the high-speed digital private line 13 is connected to the ISDN public line 101,
When switching to 102, the ISDN backup device 810
Switch 811a, 811b, 811c by MPX812
The two data signals are multiplexed and connected to the ISDN public line 101. Similarly, the ISDN backup device 820 switches three electromagnetic contacts 821a, 821b, 821c, multiplexes three data signals by MPX822, and connects to the ISDN public line 102.

Further, when switching between the host computer 1 and the data terminals 2a, 2b, 2c to the ISDN public lines 101, 103a, 103b, 103c,
The ISDN backup device 810 has three electromagnetic contacts 811a, 811
b, 811c are switched, three data signals are connected to different B channels, and connected to the ISDN public line 101. The ISDN backup device 830a switches the electromagnetic contact 831 and switches the ISDN public line 1
Connect to 03a.

As described above, in the present embodiment, in a data communication network in which a host computer communicates with a plurality of data terminals via a relay point, failure of a dedicated line passing through the relay point or a device at the relay point occurs. At times, the minimum required dedicated line can be switched to a backup line.

FIG. 13 is a block diagram showing a configuration of a data communication network to which the third embodiment of the present invention is applied.

The data communication network in this embodiment has a configuration in which a communication control device is installed at a relay point and a host computer communicates with three data terminals.

In FIG. 13, 1 is a host computer, 2a, 2b, 2c are data terminals at three points, 3 is a modem, 5, 5a, 5b, 5c are dedicated lines, 810, 820, 830, 840a, 840b, 840c are ISDN backup devices, 9 is a network configuration management device, 101, 102, 103, 104a, 104b,
104c is an ISDN public line switch, and 11 is an ISDN public line switch.

The host computer 1 and the communication control device 850 transfer information between the host computer 1 and the three data terminals 2a, 2b, and 2c and perform polling confirmation. The communication control device 850 and the three data terminals 2a, 2b, 2c transfer information between the host computer 1 and the three data terminals 2a, 2b, 2c and perform polling confirmation. .

First, a case where a failure occurs between the host computer 1 and the communication control device 850 will be described.

When the polling cannot be confirmed between the host computer 1 and the communication control device 850, the host computer 1 first notifies the maintenance person of a failure.

In the present embodiment, the host computer 1 and the communication control device
850 and communication control device 850 and three data terminals 2
Since the polling confirmation is performed between the host computer 1 and the communication control device 850, the host computer 1 sets the route connecting the host computer 1 and the communication control device 850 to the line number "1".
The route connecting the terminal and the data terminal 2a is line number "2",
A route connecting the communication control device 850, the host computer 1, and the data terminal 2b is managed as a line number "3", and a route connecting the communication control device 850 and the data terminal 2c is managed as a line number "4". .

Therefore, the failure notification performed by the host computer 1 is a notification that the line number “1” is a failure, and the maintenance person inputs the failed line number (“1”) to the network configuration management device 9. I do.

In the network configuration management device 9, for example, the host computer 1 and the ISDN backup device 810 are in Tokyo, the communication control device 850 and the ISDN backup devices 820 and 830 are in Yokohama,
Assuming that the backup device 830a is on the ship, the display screen is as shown in FIG. 14 (a).

Then, the maintenance person gives an instruction to switch between A and B to the ISDN public line.

Therefore, similarly to the above-described procedure, the switching instruction is transmitted from the network configuration management device 9 to the corresponding ISDN backup devices 810 and 820. ISDN backup devices 810 and 820 switch to ISDN public lines 101 and 102. As a result, the leased line 5
Are switched to ISDN public lines 101 and 102.

Thus, the host computer 1 and the communication control device 850
The obstacle between and recovers.

Next, a case where a failure occurs between the communication control device 850 and the data terminal 2a will be described.

When the polling cannot be confirmed between the communication control device 850 and the data terminal 2a, first, the communication control device 850 detects a failure and notifies the host computer 1. Host computer 1
Notifies the maintenance person that the line number "2" is a failure. The maintenance person inputs the line number of the failure (“2”) to the network configuration management device 9.

In the network configuration management device 9, the display screen is as shown in FIG. 14 (b).

Therefore, the maintenance person instructs to switch between C _{1 and} D to an ISDN public line.

Therefore, the switching instruction is transmitted from the network configuration management device 9 to the corresponding ISDN backup devices 830 and 840a in the same manner as the procedure described above. The ISDN backup devices 830 and 840a switch to the ISDN public lines 103 and 104a. As a result, the dedicated line 5a
Is switched to the ISDN public lines 103 and 104a.

In this way, the failure between the communication control device 850 and the data terminal 2a is recovered.

When a failure occurs in the communication control device 850, polling cannot be confirmed between the host computer 1 and the communication control device 850. Therefore, the host computer 1 first notifies the maintenance person of the failure. At this time, since the failure notification is the same as that at the time of the failure of the leased line 5, the maintenance person must
I do not know that 0 has failed.

The maintenance person inputs the line number (“1”) of the failure to the network configuration management device 9, and in the network configuration management device 9,
11 The display screen shown in Fig. (A) is displayed.
Order to switch to the public line.

Therefore, similarly to the procedure described above, the leased line 5
Switching to the public lines 101 and 102 is performed, but if a failure occurs in the communication control device 850, the failure is not recovered by this.

Then, the maintenance person knows that a failure has occurred in the communication control device 850, so disconnects the ISDN public line between A and B, and connects the ISDN public line between A and D, between A and E, and between A and F. To switch.

Therefore, similarly to the above-described procedure, the switching instruction is transmitted from the network configuration management device 9 to the corresponding ISDN backup devices 810, 840a, 840b, 840c. ISDN backup device 810,840
a, 840b, 840c are switched to ISDN public lines 101, 104a, 104b, 104c. The ISDN backup device 810 is an ISDN public line 101
The corresponding three data signals are transmitted to different B channels.

As described above, in the present embodiment, a communication control device is installed at a relay point, and in a data communication network in which a host computer communicates with a plurality of data terminals, a dedicated line or a communication control device via the communication control device is used. In the event of a failure, the required minimum dedicated line can be switched to an ISDN public line.

As shown in FIG. 15, a data communication network having a configuration in which another communication control device 860 which is a backup device of the communication control device 850 is provided. Thus, it is also possible to switch to an ISDN public line.

In the embodiment described above, the reason why the ISDN public line is used as the backup line is that it is necessary to verify the telephone number in order to connect specific backup devices to each other. If is a line that can be given to the called party, there is no particular restriction on the ISDN public line.

[Effects of the Invention] As described above, according to the present invention, when switching from the dedicated line to the backup line, there is an effect that the operation of the maintenance person can be simplified.

Further, when switching from the dedicated line to the backup line, specific backup devices are connected to each other, so that there is an effect that the line can be reliably switched.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a data communication network in the prior art, FIG. 2 is an explanatory diagram showing a procedure for switching to a telephone public line in the event of a failure in a dedicated line in the prior art, and FIG.
FIG. 4 is a block diagram showing a configuration of a data communication network to which the first embodiment of the present invention is applied. FIG. 4 is an explanatory diagram showing a procedure for switching to an ISDN public line in the event of a failure of a dedicated line in the present embodiment. FIG. 5 is an explanatory view showing a screen display example of the host computer or the network configuration management device in the present embodiment, and FIG. FIG. 7 is an explanatory diagram showing the contents of a switching instruction transmitted from the network configuration management device to the ISDN backup device. FIG. 8 is a block diagram showing an example of the configuration of the network configuration management device. a) is a block diagram showing an example of the configuration of an ISDN backup device, and FIG. 9 (b)
9 is an external view of the ISDN backup device, FIG. 9C is an explanatory diagram showing an example of registration of a telephone number of the network configuration management device, and FIG. 10 is a configuration of a data communication network to which the second embodiment of the present invention is applied. FIG. 11 is an explanatory diagram showing a screen display example of the network configuration management device in the present embodiment, FIG. 12 is a block diagram showing one configuration example of the ISDN backup device in FIG. 10,
FIG. 13 is a block diagram showing a configuration of a data communication network to which the third embodiment of the present invention is applied, FIG. 14 is an explanatory diagram showing a screen display example of a network configuration management device in this embodiment, and FIG. FIG. 13 is a block diagram illustrating a configuration of a data communication network to which a dedicated line backup system according to a fourth embodiment of the present invention is applied. 1 Host computer, 2, 2a, 2b, 2c Data terminal, 3
… Modem, 4 …… Dial backup device, 5,5a, 5
b, 5c ... dedicated line, 6 ... phone public line, 7 ... exchange of telephone public line, 8,810,820,830,830a, 830b, 830c, 840a,
840b, 840c: ISDN backup device, 9: Network configuration management device, 10, 101, 102, 103, 103a, 103b, 103c, 104a, 104b, 10
4c… ISDN public line, 11… ISDN public line switch, 12
…… Multiplexer, 13 …… High-speed digital leased line, 81…
... Display, 82 ... Keyboard, 83 ... Storage device,
84,94… Microprocessor (MPU), 85… ISDN card, 86,95… B channel controller (LAPB), 87,96
…… D channel controller (LAPD), 88,98,824 …… I
SDN interface circuit (INF), 90, 811a, 811b, 811c, 82
1a, 821b, 821c, 831 Electromagnetic contact, 91 Liquid crystal display, 92 Keypad, 93 Memory, 97 Data rate converter (RA), 812,822 Data multiplexing circuit (MP
X), 823: Data selection circuit (SEL).

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-157634 (JP, A) JP-A-2-60337 (JP, A) JP-A-2-260839 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H04M 3/00 H04L 12/24-12/26 H04L 1/22

Claims (9)

(57) [Claims] In a data communication network in which a backup device having a function of switching a dedicated line to a public line is provided at a plurality of points when a failure occurs between two points connected by a dedicated line, Sometimes, among the plurality of backup devices, two backup devices are designated as backup devices on the transmitting side, and designated as backup devices on the receiving side, and the backup device on the transmitting side is designated. Along with the instruction to designate to the calling side, the telephone number of the backup device of the receiving side is externally given via the public line, and the instruction to designate to the backup device of the receiving side to the receiving side. Along with
A step of externally providing the telephone number of the backup device on the calling side via the public line, and a step of transmitting from the backup device designated as the calling side a public line capable of transmitting the telephone number of the own device when making a call. Transmitting a call to the backup device designated as the receiving side, and in the receiving-side backup device receiving the call, the telephone number of the transmitting-side backup device transmitted by the public line, Comparing the telephone number of the calling backup device with the telephone number of the calling side, and returning a response if they match, after the above two steps, the two backup devices respectively connect the dedicated line to the public line. A dedicated line backup method. 2. An instruction to designate to said transmitting side, and
When giving the called party's telephone number, an instruction to be designated to the called party, and the calling party's phone number from outside via the public line, the information is provided to each of the plurality of backup devices. Is registered in advance, and when each backup device receives a call,
2. The dedicated line backup method according to claim 1, wherein the telephone number of the caller is compared with a telephone number registered in advance, and a call is answered if the telephone numbers match. 3. A backup device provided at each of two points connected by a dedicated line and having a function of switching the dedicated line to a public line at the time of a failure between the two points; A dedicated line backup system including at least one network configuration management device having a function of transmitting a call via the public line to the two backup devices and transmitting a switching instruction for switching the dedicated line to the public line. In the above, the network configuration management device transmits, at the time of the failure between the two points, a switching instruction including designation of one of the two backup devices as the backup device on the transmission side, and the other, the backup device on the reception side The backup device has a means for transmitting a switching instruction including a designation to perform transmission. Means for transmitting to the backup device designated as the receiving side via a public line capable of transmitting the telephone number of the own device at the time; and A means for comparing the telephone number of the transmitting apparatus transmitted by the public line with the telephone number of the backup apparatus of the transmitting apparatus which is given in advance, and returning a response when they match, If the response from the called-side backup device is received, the dedicated line is switched to the public line, and if designated as the called side, the private line is switched to the public line when the telephone number matches. A dedicated line backup system comprising: means for switching to a line. 4. The switching instructing means of the network configuration management device sends a switching instruction including a telephone number of the receiving-side backup device to the transmitting-side backup device together with an instruction to designate the transmitting-side backup device. In addition, the backup device on the receiving side is instructed to be designated as the receiving side,
4. The dedicated line backup system according to claim 3, wherein a switching instruction including a telephone number of the backup device on the transmitting side is transmitted. 5. Each of the backup devices has a means for storing a telephone number of the network configuration management device, and, when there is an incoming call from a public line, acquires the telephone number of the source of the call and registers it in advance. Means for collating with a telephone number and responding to a call when they match, wherein the switching instruction transmitting means of the network configuration management device transmits the switching instruction when the response is received. Item 5. The dedicated line backup system according to any one of items 3 and 4. 6. The backup device according to claim 1, wherein said switching means switches said dedicated line to a public line, based on a telephone number of said network configuration management device stored in advance.
Means for transmitting via the public line, and means for transmitting information to the effect that the dedicated line has been switched to the public line to the network configuration management device when a response is returned from the network configuration management device. The dedicated line backup system according to claim 5, comprising: 7. A backup which is provided at any one of a plurality of points of a data communication network and switches a dedicated line to a public line when a switching instruction is received when a failure occurs between two points connected by a dedicated line. In the apparatus, when the switch instruction including the designation as the backup device on the transmitting side or the designation as the backup device on the receiving side is transmitted at the time of the failure between the two points, means for receiving the switching instruction; If designated as, means for transmitting to the backup device designated as the receiving side via a public line capable of transmitting the telephone number of the own device at the time of calling, and, if designated as the receiving side, Upon receiving the call, the telephone number of the transmitting device transmitted by the public line is compared with the telephone number of the backup device of the transmitting device which is given in advance, Means for sending back a response, and, if specified as the calling side, upon receiving a response from the called-side backup device, switching the dedicated line to the public line and specifying as the called side Means for switching the dedicated line to the public line when the telephone numbers match. 8. The switching instruction received by the means for receiving the switching instruction includes a switching instruction including a telephone number of a backup device on the receiving side, together with an instruction to designate the transmitting side, and
The backup device according to claim 7, wherein the instruction is a switching instruction including a telephone number of the backup device on the calling side together with the instruction to specify the receiving side. 9. Each of the backup devices includes: means for storing a telephone number of a caller of the switching instruction; and, when there is an incoming call from a public line, the telephone number of the caller is acquired and registered in advance. Means for checking the telephone number in question and responding to a call when the telephone number matches, and wherein the means for receiving the switching instruction receives a switching instruction received after transmitting the response. The backup device according to any one of the preceding claims.