JP2551838B2 - Backup line switching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used for backup when a leased line fails.
The present invention provides a backup line switching method for switching a connection between a first device and a second device between a dedicated line and a backup line, by confirming each other by a password between the first device and the second device. The purpose is to prevent erroneous switching due to erroneous incoming calls.

[Conventional technology]

FIG. 25 shows an example of conventional equipment connected via a dedicated line and a backup line. In this example, a cash dispenser is used as a terminal.

The center device 1 and the cash dispenser 9 are connected via a modem 3, a four-wire dedicated line 5 and a modem 7. The modem 3 on the center side and the motem 7 on the terminal side are further connected via a telephone network 11 by a backup line using two telephone lines 13.

Figure 26 shows the conventional backup line switching procedure when the leased line fails.

When the leased line 5 fails, the modem 3 on the center side
Manually calls the modem 7 on the terminal side via the telephone network 11 and the telephone line 13. When the modem 7 detects an incoming call (IR reception) on both of the two telephone lines 13 simultaneously or successively, it automatically responds by off-hook, and the line "1" (corresponding to the receiving line on the terminal side) and the line "2" are sent. "(Corresponding to the transmission line on the terminal side) connection to the dedicated line 5
Switch to telephone line 13. When the modem 3 on the terminal side receives the response signal on both of the two telephone lines 13, the connection of the lines "1" and "2" is switched from the dedicated line 5 to the telephone line 13.

In this way, the connection from the private line 5 to the telephone line 13, which is a backup line, is switched and communication becomes possible.

To restore the connection from the telephone line 13 to the dedicated line 5, the telephone line 13 is manually disconnected from the modem 3 on the center side. As a result, the modem 7 on the terminal side receives the disconnected BT from the analog exchange and restores the connection of the line "1" from the telephone line 13 to the dedicated line 5. Also for line "2",
The same procedure is executed between the modem 3 on the center side and the modem 7 on the terminal side to restore the connection from the telephone line 13 to the dedicated line 5.

In this way, the backup telephone line 13
The connection is switched to the dedicated line 5, and communication becomes possible.

Further, the modem 7 on the terminal side starts the timer T when it detects the first incoming call from the modem 3 on the center side and automatically responds, and waits until the timer T times out to receive the incoming call on the other line. Does not come, disconnect the first incoming call. This prevents erroneous operations due to erroneous incoming calls.

[Problems to be Solved by the Invention]

However, the modem on the terminal side has a drawback that erroneous switching is made when two erroneous calls are continuously received from the two telephone lines of the backup line before the timeout by the timer T occurs.

It is an object of the present invention to solve the above problems and provide a highly reliable backup line switching system.

[Means for solving the problem]

The backup line switching method of the present invention is a dedicated line,
A first device and a second device connected to each other via this dedicated line, a backup line provided separately from this dedicated line, and a line connecting the first device and the second device to the dedicated line and the backup line. In the backup line switching method including a switching unit for switching between and, the backup line is a public network line, and the first device calls the second device via the backup line and the called second device. In the second device, the second device includes a confirmation unit that confirms that the notified password matches the password stored in the own device, and the switching unit includes
It is characterized by including means for executing line switching on condition that the confirmation means confirms that the passwords match.

The backup line is an ISDN network line capable of transmitting / receiving user / user information, the password notifying means includes means for adding a password to the user / user information, and the calling means performs switching operation to the user / user information. It is desirable to include a means for adding a command command for adding a password and a means for transmitting the user / user information to which the password and the command command are added.

User-user information is added to a message including address information and sent. At this time, it is desirable for the receiving side to check not only the password but also the sender based on the address information.

When an ISDN network line (hereinafter referred to as "ISDN line") is used, a remote control device connected to the ISDN network may be provided separately from the first device and the second device in order to remotely control the line switching. desirable.

The remote control device adds a password to the user / user information and a command to switch the line between the first device and the second device, and a call setup message including the user / user information. And means for delivering to one device.

At this time, the first device confirms whether or not the received password matches the value set in advance in its own device, and the calling device and the password notification according to the command command included in the call setup message in which the password is confirmed. It is necessary to include means for activating the means.

The first device further includes means for receiving a call setup message from the remote control device via the D channel while being connected to the second device via the backup line, and a password and a password to the second device via the D channel. It is preferable that the switching means includes means for transmitting an instruction command for disconnecting the backup line, and the switching means includes means for switching the line from the backup line to the dedicated line.

[Work]

By using the password and further the address information, the communication partner can be confirmed, malfunction due to incorrect connection can be prevented, and reliability of backup line switching can be improved.

In particular, when using the ISDN line, the line quality is superior to the telephone line, and backup can be performed at the same communication speed as the leased line.

Also, by using the ISDN line, the backup line can be used for other communication while the leased line is operating normally.

By providing the remote control device, it is not necessary to dispatch or arrange personnel for a failure or restoration of the leased line.

Specifically, one of the devices connected to the dedicated line or the remote control device serves as the calling device, and at the time of calling, sends a call setting message to which address information and user / user information including a password and command command are added. To do.

When the ISDN network receives this call setup message, it sends the call setup message to which the information is added to the receiving side device.

Upon receiving the call setup message, the receiving side device confirms whether the address information and password set in advance in the device itself match the password in the address information and the user / user information coming from the ISDN network,
When they match, a response message to which user / user information including a password and a response command is added is sent.

The response message containing this user information is IS
It is sent to the originating device via the DN network.

The calling side device confirms whether or not the password set in advance in the own device matches the password included in the user / user information sent from the called side device.

If the calling device is a remote control device, after the above procedure the called device becomes the calling device and the other device connected by the dedicated line becomes the called device and the same procedure is performed. Run.

In addition, by using the incoming call notification service on the ISDN network, it is possible to restore the connection to the dedicated line by remote control.

For this purpose, the remote control device sends a call setup message to which address information and user information are added at the time of calling. The ISDN network adds these pieces of information to the call setup message and sends it to the receiving side device. At this time, the call setup message is sent using the D channel. Therefore, B
Messages can be posted even if the channel is in use without affecting its operation.

The receiving side device receiving this call setup message determines whether or not the address information and password set in advance in the device itself match the password in the address information and user / user information sent from the ISDN network. It is confirmed, and if they match, the line is switched with the device on the other side connected by the backup line. Further, the receiving side device sets a password and a response command in the user information to the remote control device,
A response message with this user / user information added is sent.

This response message is transferred to the remote control device via the ISDN network.

The remote control device confirms whether or not the password set in advance in the device itself matches the password in the user / user information included in the transferred response message. If they match, the response command in the user / user information is read. As a result, it is possible to know that the recovery operation has been performed normally.

In order to use the backup line for remote control, a call waiting method may be used. However, call waiting has the drawback of affecting the data being communicated.

〔Example〕

FIG. 1 is a block diagram showing a backup line switching system according to the first embodiment of the present invention.

In this embodiment, a center-side device and a terminal-side device, specifically a center-side device, are provided as a first device and a second device which are provided with a four-wire type dedicated line 5 and are connected to each other via the dedicated line 5. A center device 1, a modem 3 and a line switching device 4, and a line switching device 6 as a terminal side device,
A modem 7 and a cash dispenser 9 are provided. Furthermore, the ISDN line 12 is provided as a backup line provided separately from the dedicated line, and the line switching device is a switching means for switching the line connecting the center side device and the terminal side device between the dedicated line 5 and the backup line. Prepare within 4 and 6.

 Further, a remote control device 14 is connected to the ISDN network 10.

The lines connected to the line switching devices 4 and 6 and the remote control device 14 receive user-user information service.
Also, the line switching device 4 on the Santa side receives the incoming call notification service during communication.

FIG. 2 is a block diagram showing an example of the line switching device.

This line switching device includes a switching device 21, an interface circuit.
22, a line terminating device 23, a control circuit 24, a read only memory 25 and a random access memory 26.

The switch 21 connects the lines "1" and "2" connected to the modem to either the dedicated line 5 or the ISDN line 12. The interface circuit 22 has lines "1" and "2".
Provides an S interface for connecting the ISDN line 12 and exchanges D channel signals with the control circuit 24. The line terminating device 23 uses the T interface as an ISDN line.
Connect to 12. The control circuit 24 performs communication by the D channel, control of the switching device 21, execution of the line connection procedure, and other control in accordance with the control program stored in the read-only memory 25. The read-only memory 25 stores a password, address information of the own device, address information of the partner line switching device, and other fixed information.

FIG. 3 is a block diagram showing an example of the remote control device.

This remote control device includes a manual input unit 31, a display unit 32, a control circuit 33, a read-only memory 34, and a random access memory 3.
5. The interface circuit 36 and the line terminating device 37 are provided.

The manual input unit 31 is for manually inputting address information of the line switching device, a password and other control information. The display unit 32 displays the control content and the control result.
The control unit 33 uses the data input by the manual input unit 31 according to the control program stored in the read-only memory 34 to perform line connection, line switching, and other control.
The control circuit 33 includes an interface circuit 36 and a line terminating device 37.
Connected to the ISDN line 12 via.

FIG. 4 shows the format of the call setup message and the response message.

FIG. 4 (a) shows a call setup message on the calling side, which includes a protocol identifier, a call number, a message type, a transfer capability,
It includes channel identifier, facility, calling number, calling subaddress, called number, called subaddress, lower layer compatibility, and user-user information. This call setup message is sent from the device on the calling side to the ISDN network 10.

FIGS. 4 (b) and 4 (c) show call setup messages on the receiving side when the receiving line is a dial-in line and when it is not. When the line on the called side is a dial-in line, the message from the calling side is transmitted as it is to the device on the called side. If the line is not a dial-in line, it does not include the called number and cannot be used for device confirmation.

FIG. 4 (d) shows a response message. The response message includes protocol identifier, call number, message type, lower layer compatibility, and user / user information. As the response message, the message from the calling side is transmitted to the called side as it is.

The above message format is TTC standard JT-Q93
1, "ISDN user / network interface, layer 3 specifications"
Complies with.

 5 to 9 show the circuit switching control means.

FIG. 5 shows a procedure for activating the switching control by the remote control device.

The remote control device sets a password and an instruction command for performing switching control in the user / user information, and sends a call setting message including the user / user information and address information to the line switching device on the center side.

The line switching device on the center side checks whether or not the address information included in the received call setting message and the password included in the user / user information match the information set in advance in the own device. If they match, the command command included in the user-user information is read, and a response message is sent to the remote control device. This response message includes the user and user information for which the password and the command reception response command are set.

The remote control device checks whether the password included in the user / user information in the received response message matches the information set in advance in the device itself. If they match, the response command in the user / user information is read, and when the normal operation of the line switching device is confirmed, a disconnection message is sent. When the remote control device receives the release message from the ISDN network, it starts the timer T ₁ .

FIG. 6 shows a procedure for switching from the dedicated line to the backup line by the line switching device on the center side which receives the command from the remote control device.

The line switching device on the center side adds the address information and the user / user information in which the password is set to the call setting message, and sends the call setting message to the line switching device on the terminal side.

The line switching device on the terminal side checks whether or not the address information of the received call setting message and the password included in the user / user information match the information set in the own device in advance. If they match, the response message including the user / user information for which the password is set is sent to the line switching device on the center side.

The line switching device on the center side receiving this response message confirms whether or not the password included in the user / user information in this message roughly matches the information set in the own device. If they match, the connection of the line "1" (corresponding to the transmission line on the center side) is switched from the dedicated line to the ISDN line.

When the line switching device on the terminal side receives the response confirmation message from the ISDN network, it switches the connection of line "1" (corresponding to the receiving line on the terminal side) from the dedicated line to the ISDN line.

Similarly, for the line "2", the switching operation is performed between the line switching devices on both the center side and the terminal side by the procedure of call setting, call setting acceptance, response, and response confirmation. In this way, the connection is switched from the leased line to the backup ISDN line.

7 and 8 show a procedure for confirming by the remote control device that the line between the line switching devices has switched to the backup line.

When the timer T ₁ expires, the remote control device will add call information to the line switching device on the center side with the address information and the user / user information to which the command command for confirming the switching is set. Send a message.

When the line switching device on the center side receives the call setting message of communication notification during communication, the address information included in the message and the password in the user / user information are
It is confirmed whether the information matches the information set in the device in advance. If they match, the command command in the user-user information is read, and the paging message is returned to the remote control device.

After that, the line switching device on the center side sends an additional information message to the ISDN network, and line B used by line "1" is used.
Put the channel on hold.

Following this, the line switching device on the center side sets a password and a response command for notifying the completion of switching to the user / user information, and sends a response message containing this user / user information to the remote control device.

The remote control device controls the user information included in the response message.
It is confirmed whether the password in the user information matches the information set in the own device in advance. If they match, the response command in the user / user information is read and waits.

After this, the line switching device on the center side again sends an additional information message to the ISDN network to hold the call during communication with the remote control device and restore the lines "1" and "2" to the communication state. When the lines "1" and "2" have returned to the communication state, a disconnection message is sent to disconnect the call on hold with the remote control device.

When the remote control device receives the release completion message,
The completion of switching is displayed on the display unit and the operator is notified of the completion of switching.

By the above procedure, the switching from the dedicated line to the backup line by the remote control device is completed.

FIG. 9 shows a procedure for restoring the connection from the backup line to the dedicated line under the control of the remote control device.

In order to restore the connection, the remote control device sets a password in the user / user information and an instruction command for performing a disconnection operation, and sends a call setting message including the user / user information and address information to the line switching on the center side. Call the device.

The line switching device on the center side confirms whether the address information and the password included in the received call setting message match the information set in advance in the own device. If they match, the command command included in the user-user information is read, and the calling message is sent.

After this, the line switching device on the center side starts the disconnection recovery operation and sends a disconnection message to the line switching device on the terminal side. When the release message is received from the ISDN network, the line connected to the line "1" is switched from the ISDN line to the dedicated line.

Upon receiving the release completion message from the ISDN network, the line switching device on the terminal side also switches the line connected to the line "1" from the ISDN line to the dedicated line.

Similarly, for the line "2", the switching operation is executed between the line switching devices on both the center side and the terminal side by the same procedure.

In this way, the connection from the backup ISDN line to the leased line is switched.

Thereafter, the line switching device on the center side sets a password and an instruction command for notifying the completion of recovery in the user / user information, and sends a response message including the user / user information to the remote control device.

The remote control device confirms whether or not the password included in the response message matches the information set in the device itself in advance. If they match, the response command in the user / user information is read and the process waits.

The line switching device on the center side, when receiving the response confirmation message for the transmitted response message from the ISDN network, transmits the disconnection message.

Upon receiving the release completion message from the ISDN network, the remote control device displays the recovery completion on the display unit and notifies the operator of the connection recovery completion.

By the above control procedure, the switching from the backup line to the dedicated line by the remote control device is completed, and the communication via the dedicated line becomes possible.

By the above operation, it is possible to switch to the backup line and restore to the dedicated line by remote control.

In this embodiment, it is possible to switch the line by a manual operation from the line switching device on the center side without using the remote control device. In that case, the procedure shown in FIG. 6 or 7 is executed.

FIG. 10 is a block diagram showing a backup line switching system according to the second embodiment of the present invention.

This embodiment differs from the first embodiment in that the ISDN network 10 and the line switching device 6 on the terminal side are connected by a telephone network 11 and two telephone lines 13.

The ISDN line connected to the remote control device 14 and the line switching device 4 receives the user / user information notification service.
In addition, the line connected to the line switching device 4 receives the incoming call notification service during communication.

FIG. 11 shows a block configuration diagram of the line switching device 4 on the center side, and FIG. 12 shows a block configuration diagram of the line switching device 6 on the terminal side.

Since the line switching device 4 on the center side is connected to the ISDN line 12, its configuration is the same as that of the line switching device in the first embodiment. However, unlike the first embodiment, a push button signal generation circuit 27 is provided to convert the password into a push button signal.

Since the line switching device 6 on the terminal side is connected to the existing telephone network 11, the configuration of the part connected from the switch 21 to the backup line is different from the device used in the first embodiment.
That is, the switch 21 connects the lines “1” and “2” connected to the modem to either the dedicated line 5 or the telephone line 13. A network control circuit 28 is provided between the switch 21 and the telephone line 13, and this network control circuit 28 is a control circuit 24.
Controlled by.

 13 to 17 show the procedure of line switching control.

FIG. 13 shows the procedure for starting the switching control by the remote control device, and the contents thereof are the same as the procedure shown in FIG.

FIG. 14 shows the procedure for switching from the dedicated line to the backup line by the line switching device on the sensor side that receives the command from the remote control device.

The line switching device on the center side sends a call setting message to the line switching device on the terminal side.

When the line switching device on the terminal side detects an incoming call (IR reception), it automatically responds by off-hook. This enables communication between the line switching devices on both the center side and the terminal side. At this time, the line switching device on the center side converts the password into a PB signal and sends it to the line switching device on the terminal side.

The line switching device on the terminal side confirms whether the received password matches the password set in advance in its own device, and if it matches, the password is sent to the line switching device on the center side. The PB signal is converted and sent out, and the connection of line "1" (corresponding to the receiving line on the terminal side) is switched from the dedicated line to the telephone line.

The line switching device on the center side checks whether or not the received password matches the password set in advance on the own device, and if they match, the line "1" (corresponding to the transmission line on the center side ) Connection is switched from the leased line to the ISDN line.

Similarly for line "2", the connection is switched between the line switching devices on both the center side and the terminal side.

In this way, the connection is switched from the leased line to the backup ISDN line and telephone line.

15 and 16 show the procedure for confirming from the remote control device that the connection between the line switching devices on both the center side and the terminal side has been switched to the backup line.
This control procedure is equivalent to the procedure of the first embodiment shown in FIGS. 7 and 8.

Figure 17 shows the procedure for restoring the connection from the backup line to the leased line by operating the remote control device.

The remote control device sets a password and a command command for performing a disconnection operation in the user / user information, and sends a call setting message including the user / user information and address information to the line switching device on the center side.

The line switching device on the center side confirms whether the address information in the received call setting message and the password in the user / user information match the information set in advance in the own device. If they match, the command command included in the user-user information is read, and the calling message is sent.

Thereafter, the line switching device on the center side starts the disconnection recovery operation and sends a disconnection message to the line switching device on the terminal side. When the release message is received from the ISDN network, the line connected to the line "1" is switched from the ISDN line to the dedicated line.

When the line switching device on the terminal side receives the BT signal after disconnection from the analog exchange, the line switching device switches the line connected to the line “1” from the telephone line to the dedicated line to restore the connection.

Perform the same procedure for line "2" to switch the backup line from the ISDN line and telephone line to the dedicated line.

Further, the line switching device on the center side sets a password and a response command for notifying the completion of recovery in the user / user information, and sends a response message including the user / user information to the remote control device.

The remote control device confirms whether or not the password included in the response message matches the information set in the device itself in advance. If they match, it receives the response command in the user-user information and waits.

When the line switching device on the center side receives the response confirmation message for the transmitted response message from the ISDN network,
Send a disconnect message.

Upon receiving the release completion message from the ISDN network, the remote control device displays the recovery completion on the display unit and notifies the operator of the connection recovery completion.

As a result, switching from the backup line to the dedicated line is completed, and communication via the dedicated line becomes possible.

By the above operation, switching and restoration between the ISDN line and the telephone line, which are backup lines, and the dedicated line can be performed by remote control.

In this embodiment, it is possible to switch the line by a manual operation from the line switching device on the center side without using the remote control device. In that case, the procedure shown in FIG. 14 or FIG. 17 is executed.

FIG. 18 is a block diagram showing a backup line switching system according to the third embodiment of the present invention.

This embodiment differs from the first embodiment in that a manual switch 16 is provided on the center side and the dedicated line 5 and the backup line are switched by the manual switch 16. Manual switch 16
Connects either the modem 3 and the leased line 5, or the modem 3 and the line switching device 4.

The switching procedure is the same as the procedure of the first embodiment shown in FIGS. 6 and 9. However, the line switching on the center side is performed by the manual switching device 16, which is different from the first embodiment.

In this embodiment, it is necessary to manually switch between the ISDN line and the leased line, but this makes it possible to connect to an arbitrary leased line and improve the economy.

FIG. 19 is a block diagram showing a backup line switching system according to the fourth embodiment of the present invention.

This embodiment is different from the second embodiment in that a manual switch 16 is provided on the center side and the dedicated line 5 and the backup line are switched by the manual switch 16. Manual switch 16
Connects either the modem 3 and the leased line 5 or the modem and the line switching device 4.

The switching procedure is the same as the procedure of the second embodiment shown in FIGS. 14 and 17. However, the line switching on the center side is performed by the manual switch 16 unlike the second embodiment.

In this embodiment, it is necessary to manually switch between the ISDN line and the leased line, but this makes it possible to connect to an arbitrary leased line and improve the economy.

FIG. 20 is a block diagram showing a backup line switching system according to the fifth embodiment of the present invention.

In this embodiment, the line switching device 4 on the center side is connected to the general telephone network 11 via two telephone lines, and the line switching device 6 on the terminal side is connected to the ISDN network 10 via one line. Is different from the fourth embodiment. The ISDN network 10 and the general telephone network 11 are connected to each other.

 21 and 22 show the operation procedure of this embodiment.

The line switching device on the center side makes a manual call to the line switching device on the terminal side.

Upon receiving the call setup message, the line switching device on the terminal side returns a response message. This enables communication between the line switching devices on both the center side and the terminal side.

At this time, the line switching device on the center side converts the password into a push button signal and sends it to the line switching device on the terminal side.

The line switching device on the terminal side checks whether the received password matches the password set in advance on the device itself, and if it matches, pushes the password to the line switching device on the center side. While converting to a button signal and transmitting it, line 1 (corresponding to the receiving line on the terminal side) is connected to the ISDN line.

Also, the line switching device on the center side checks whether the received password matches the password set in advance in the own device, and if they match, the line "1"
Connect (corresponding to the transmission line on the center side) to the telephone line.

Similarly for the line "2", the line switching devices on both the center side and the terminal side are connected to the backup line in the same procedure.

The backup line is connected according to the above procedure, and the connection is switched by the manual switching device, whereby the line switching from the dedicated line to the backup line is completed and communication becomes possible.

By using the manual switching device, the device on the center side can be connected to any dedicated line, which improves the economical efficiency.

To switch the line from the backup line to the dedicated line, first disconnect the backup line. For this purpose, the backup line is manually disconnected from the line switching device on the center side, and the line "1" is disconnected from the telephone line. As a result, the line switching device on the terminal side receives the disconnection message from the ISDN network, and sends a release message to this,
Receive a release complete message. As a result, the line "1" is disconnected from the backup line.

Similarly, for line "2", the same procedure is executed between the line switching devices on the center side and the terminal side.
Disconnect from the backup line.

After this, the manual switch is switched to the dedicated line side. This enables communication via a dedicated line.

FIG. 23 is a block diagram showing the backup line switching system according to the sixth embodiment of the present invention.

In the present embodiment, the telephone line 13 of the general telephone network is used as the backup line for connecting the line switching device 4 on the center side and the line switching device 6 on the terminal side. different.

 FIG. 24 shows the line switching control procedure of this embodiment.

The line switching device on the center side makes a manual call to the line switching device on the terminal side.

When the line switching device on the terminal side detects an incoming call (IR reception), it automatically responds by off-hook. This enables communication between the line switching devices on both the center side and the terminal side. At this time, the line switching device on the center side converts the password into a push button signal and sends it to the line switching device on the terminal side.

The line switching device on the terminal side confirms whether the received password matches the password set in advance in its own device, and if it matches, push the password to the line switching device on the center side. The line signal "1" (corresponding to the receiving line on the terminal side) is switched to a connection from a dedicated line to a telephone line while being converted into a button signal and transmitted.

Further, the line switching device on the center side checks whether the received password matches the password set in advance in the own device, and if they match, the line "1" (transmission on the center side) (Corresponding to the line) to the telephone line.

Similarly, for the line "2", the same procedure is executed between the line switching devices on both the center side and the terminal side,
Connect to a telephone line.

Here, by changing the connection by the manual switch, the line is switched from the dedicated line to the telephone line, and the communication via this telephone line becomes possible.

By using the manual switching device, the device on the center side can be connected to any dedicated line, which improves the economical efficiency.

To switch the line from the backup line to the dedicated line, first disconnect the backup line. For this purpose, the backup line is manually disconnected from the line switching device on the center side, and the line "1" is disconnected from the telephone line. As a result, the line switching device on the terminal side receives the BT signal after disconnection from the analog exchange, and restores the connection of line "1" from the telephone line to the dedicated line.

Similarly, for the line “2”, the same procedure is executed between the line switching devices on both the center side and the terminal side, and the disconnection operation is performed.

After this, by switching the manual switch to the dedicated line side, the line switching from the backup line to the dedicated line is completed, and communication by the dedicated line becomes possible.

〔The invention's effect〕

As described above, the backup line switching method of the present invention can confirm the communication partner by using the password and further the address information, can prevent the malfunction due to the incorrect connection, and enhance the reliability of the backup line switching. There is an effect that can be done.

Especially when using the ISDN line, the line quality is superior to the telephone line, backup can be performed at the same communication speed as the leased line, and the backup line can be used for other communications when the leased line is operating normally. Therefore, there is an effect that the use efficiency of the line can be improved.

Also, by connecting a remote control device to the ISDN line, there is an effect that it becomes unnecessary to dispatch or arrange personnel for a failure or restoration of the leased line.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a backup line switching system according to a first embodiment of the present invention. FIG. 2 is a block diagram showing an example of a line switching device. FIG. 3 is a block diagram showing an example of a remote control device. FIG. 4 shows the format of the call setup message and the response message. FIG. 5 is a diagram showing a control procedure of line switching. FIG. 6 is a diagram showing a control procedure of line switching. FIG. 7 is a diagram showing a control procedure of line switching. FIG. 8 is a diagram showing a control procedure of line switching. FIG. 9 is a diagram showing a control procedure of line switching. FIG. 10 is a block diagram showing a backup line switching system according to the second embodiment of the present invention. FIG. 11 is a block configuration diagram of the center side line switching device. FIG. 12 is a block configuration diagram of the terminal side line switching device. FIG. 13 is a diagram showing a procedure of line switching control. FIG. 14 is a diagram showing a procedure of line switching control. FIG. 15 is a diagram showing a procedure of line switching control. FIG. 16 is a diagram showing a procedure of line switching control. FIG. 17 is a diagram showing a procedure of line switching control. FIG. 18 is a block diagram showing a backup line switching system according to the third embodiment of the present invention. FIG. 19 is a block diagram showing a backup line switching system according to the fourth embodiment of the present invention. FIG. 20 is a block diagram showing a backup line switching system according to a fifth embodiment of the present invention. FIG. 21 is a diagram showing an operation procedure. FIG. 22 is a diagram showing an operation procedure. FIG. 23 is a block diagram showing a backup line switching system according to a sixth embodiment of the present invention. FIG. 24 is a diagram showing a line switching control procedure. FIG. 25 is a block diagram showing a conventional backup line switching system. FIG. 26 is a diagram showing a conventional procedure for switching the backup line when the leased line fails. 1 ... Center device, 3, 7 ... Modem, 5 ... Private line, 9 ... Cash dispenser, 10 ... ISDN network, 11
…… Telephone network, 12 …… ISDN line, 13 …… Telephone line, 14 ……
Remote control device, 16 …… Manual switch, 21 …… Switch, 22,
36 …… Interface circuit, 23, 37 …… Line terminating equipment,
24, 33 ... Control circuit, 25, 34 ... Read-only memory, 26,
35 …… Random access memory, 27 …… Push button signal generation circuit, 28 …… Network controller, 31 …… Manual input section,
32 …… Display.

Claims (2)

(57) [Claims] 1. A dedicated line, a first device and a second device connected to each other through the dedicated line, a backup line provided separately from the dedicated line, the first device and the second device. In the backup line switching method having a switching means for switching the line connecting to and from the dedicated line and the backup line, the backup line is an ISDN network line capable of transmitting / receiving user / user information. In addition to the device and the second device, a remote control device connected to the ISDA network is provided, and this remote control device is used to switch the line between the first device and the second device for user / user information. Means to add command command and password
Including means for sending user information to the first device, the first device, a means for confirming whether the received password matches the value set in advance in its own device,
A means for adding an instruction command and a password for performing a switching operation with the second device to the user / user information according to the instruction command included in the user / user information whose password has been confirmed; and the backup line. Means for calling the second device via the means, and means for sending to the second device the user / user information to which the command command for performing a switching operation with the second device and the password are added. Including, the second device includes a confirmation means for confirming that the notified password matches the password stored in the own device, and the switching means has confirmed that the password has been confirmed by the confirmation means. Backup line switching method characterized by including means for executing line switching under the condition of 2. The first device comprises means for receiving a call setup message from the remote control device via the D channel while being connected to the second device via the backup line, and the second device via the D channel. 2. The backup line switching system according to claim 1, further comprising means for transmitting a password and a command command for disconnecting the backup line to the device, and the switching means includes means for switching the line from the backup line to the dedicated line.