JPH02260946A - Back-up system - Google Patents

Abstract

PURPOSE:To detect the fault restoration of a conventional line and to automatically switch from a standby line to the conventional line by installing a back-up releasing signal transmission means in a MODEM on the side of a data processor provided with a standby MODEM and installing a back-up releasing signal detection means in a line switching device on the side of a data terminal equipment. CONSTITUTION:When the state of a private line 1 is deteriorated, CPU 7 in the data processor switches connection with the MODEM 3 using the private line 1 in a deteriorated state to the standby MODEM 5. DBU 6 on the side of the data terminal equipment detaches the private line 1 with respect to a MODEM 4 and the connects it to the standby line 2. At the same time, a private line interface is connected so that it is turned back in a loop state. The MO DEM 3 recognizes the state of the line by testing the normal/defective of a signal returned from the private line 1. When it becomes normal, a back-up releasing signal is transmitted. DBU 6 on the side of the data terminal equipment identifies the back-up releasing signal, disconnects a loop and switches the MODEM 4 to the side of the private line 1.

Description

[Detailed Description of the Invention] [Summary] Regarding a backup method in the event of a data communication line failure, a modem backed up by a standby modem is provided for the purpose of detecting recovery of the original line and quickly switching back to the original line. The system is equipped with a test means for transmitting a test pattern signal and testing the line based on the signal received in return, and a backup release signal sending means for sending a signal for canceling the backup, as well as an original line interface for the line switching mechanism. It is equipped with a line looping means for looping back and a means for detecting a backup cancellation signal sent by an opposing modem through the original line, and when switching from the original line to a protection line and performing backup, the line switching mechanism , put the original line interface in a return loop state, send a test pattern signal from the modem connected to the original line, test the original line using the signal received in return, and cancel the backup if recovery is confirmed. It is configured to send a signal to cancel the backup and switch back to the original line.

[Industrial application field]

The present invention relates to a backup method in the event of a data communication line failure, and in particular, diagnoses the status of the original data line when a modem that transmits data through an analog telephone line backs up to a backup line due to a failure in the original line. Concerning test methods.

[Conventional technology]

As shown in FIG. 5, in a system in which a data processing device connects to a plurality of data terminal devices via an original line (for example, a dedicated line) 1, and data processing is performed based on data communication, In order to back up the line (for example, a leased line) 1 in the event of a failure, the data processing device side is equipped with a spare modem 5 and a dial backup unit (which automatically dials the telephone number of the other party in order to back up the line through the switched line in the event of a failure of the original line). To deal with this problem, two devices (hereinafter abbreviated as DBU) 9 having the function of automatically receiving a call and switching lines are provided, and a DBU 6 is provided on the data terminal device side.

That is, the DBU 9 connected to the backup modem 5 on the data processing device side dials the telephone number of the data terminal device connected to the original line (dedicated line) 1 where the failure occurred, and calls the telephone number through the switched line 2. In response to the call, the DBU 6 on the data terminal side switches the modem 4 from the original line (dedicated line) 1 to the protection line (switched line) 2.

In this way, conventionally, when a failure occurs in the original data line 1 and backup is to be performed on the protection line 2, the original modem 3 and the original line 1 are completely disconnected from the data line and connected via the protection modem 5. It was intended to connect to protection line 2.

[Problem to be solved by the invention]

As shown in Figure 6, the main parts are extracted, in the conventional switching to protection line, it is possible to avoid the failure by switching to protection line 2, but the original line 1 is disconnected by DBtJ6. There was a problem in that even if the original state of the line 1 was restored thereafter, it could not be recognized.

The backup line 2 is normally a switched line, and charges are applied depending on the usage time, so if the leased line 1 is restored, I would like to switch to the leased line 1 as soon as possible, but in order to recognize the recovery, it is necessary to There was no other way than to conduct tests, and it was not possible to quickly recognize recovery.

The problem to be solved by the present invention is to provide a backup method that solves these conventional problems.

[Means to solve the problem]

FIG. 1 is a block diagram showing the configuration of the present invention.

In the figure, 1 is the original line and 2 is a protection line, both of which are 4-wire lines.

3.4 is a modem, which performs data communication through the original line 1.

5 is a backup modem, and modem 3 is used in the event of a failure in the original line.
Instead, data communication is performed with the modem 4 through the protection line 2.

Reference numeral 6 denotes a line switching mechanism, which connects to the other party through the protection line 2 and switches the modem 4 to the protection line 2.

Reference numeral 31 denotes a test means, which tests the line by sending out a test pattern signal and receiving the signal back.

Reference numeral 32 denotes a backup cancellation signal sending means, which sends out a signal for canceling backup.

Reference numeral 61 denotes a line return means, which puts the original line interface into a return loop state.

Reference numeral 62 denotes a backup cancellation signal detection means, which detects a backup cancellation signal sent from the opposing modem through the original line.

[For production]

In the present invention, the modem 3 on the data processing device side equipped with the backup modem 5 is provided with the testing means 31 and the backup cancellation signal sending means 32, and the line switching mechanism (for example, DBU) 6 on the data terminal side is provided with the Means 61 and backup release signal detection means 62 are provided.

Then, when switching from the original line to the protection line and performing a backup, the DBU 6 puts the original line interface into a return loop state, and the modem 3 connected to the original line sends out a test pattern and receives it in return. The original line is tested using the signal, and once recovery is confirmed, a backup release signal is sent out.

The DBU 6 detects a backup cancellation signal from among the signals sent from the modem 3, and upon receiving it, cancels the backup and switches back to the original line.

With the above configuration, it is possible to detect failure recovery of the original line and automatically switch from the protection line to the original line.

(Embodiment) FIG. 2 is a diagram showing a system configuration of an embodiment of the present invention.

In the figure, the same reference numerals as in FIG. 1 indicate the same objects.

7 is a data processing device CPU, which controls the entire data processing device. It shall include a communication control device.

8 is a data terminal device.

Reference numeral 9 denotes a DBU on the data processing device side, which performs automatic dialing and automatic receiving of calls to designated telephone numbers.

A network management device (NMS) 10 manages a line network connected to the data processing device.

FIG. 3 is a diagram showing the main part configuration of an embodiment of the present invention.

FIG. 3(a) shows the configuration of the main parts of the modem related to the present invention.

311 is a test pattern generation section, and the generated test pattern signal is converted into an analog signal in the transmission section 33 and sent to the line.

Reference numeral 312 denotes an inspection section, which inspects the pattern of the received signal received through the line and converted into a digital signal by the receiving section 34 to determine whether the line is good or bad. If the test result is good, it is determined that the line has been restored, and the test Bakun generation unit 311
is notified to stop sending out the test pattern, and is notified to the backup cancellation signal sending unit 32 to send out a backup cancellation signal.

FIG. 3(1)) shows the configuration of the main parts of the DBU that are relevant to the present invention.

Reference numeral 63 denotes an automatic call reception unit, which processes calls in response to calls through the switched lines, and notifies the switching control unit 611 when calls are received from the two switched lines. Switching control section 611
controls switch 612 to switch from a leased line to a switched line, and controls switch 613 to form a return loop.

Reference numeral 62 denotes a backup cancellation signal detection section, which receives a signal from a dedicated line, compares it with a predetermined pattern of signals (backup cancellation signal), and sends a detection signal to the switching control section 611 if they match. Upon receiving this detection signal, the switching control section 611 switches the switch 612 and the switch 6.
13 to return the line interface to its original state.

FIG. 4 is a flowchart showing processing according to an embodiment of the present invention. Hereinafter, the operation at the time of failure will be explained according to the processing steps of the flowchart.

■If the condition of the dedicated line l deteriorates, proceed to step ■.

■CPU of data processing device (including communication control device) 7
switches the connection to the modem 3 using the deteriorated dedicated line 1 to the backup modem 5, and the network management device (NMS) 10 sends the telephone number of the other party to connect to the deteriorated condition line 1 to the DBU 9 (4-wire type Therefore, 2 lines) are automatically transmitted, and the backup modem 5 is initialized with the same data as the modem 3 settings.

(2) The DBU 6 on the data terminal side disconnects the dedicated line 1 to the modem 4 and connects it to the protection line 2 because there are two calls through the exchange line 2. At the same time, the dedicated line interface is connected so as to loop back.

(2) Simultaneously with the switching, the modem 3 on the data processing device side generates a test pattern signal and starts transmitting it.

The test pattern signal returns to the modem 3 through a loop formed by the data terminal device side DBU 6.

■The modem 3 recognizes the line condition by testing the quality of the signal returned from the dedicated line 1 (if the line condition is still bad, the test result will be bad).

■If the test results are good, proceed to step ■.
If the test result is still poor, return to step ■.

(2) The modem 3 sends out a backup release signal instead of the test pattern signal.

(2) The data terminal device side DBU 6 identifies the backup cancellation signal, cuts the loop, and switches the modem 4 to the dedicated line 1 side.

■The data processing device and the data terminal device perform data communication through the original line (dedicated line 1).

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, it is possible to recognize when the original data line status has been restored to normal, and it is possible to quickly switch back to the original data line, allowing the use of switched lines. This has the effect of minimizing time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a diagram showing the system configuration of an embodiment of the present invention, FIG. 3 is a diagram showing the main part configuration of an embodiment of the present invention, and FIG. FIG. 5 is a flowchart showing processing according to an embodiment of the present invention, FIG. 5 is a diagram showing backup using a backup modem and a backup line, and FIG. 6 is a diagram explaining problems in the prior art. In the figure, l is the original line (dedicated line), 2 is the protection line (switched line), 3.4.5 is the modem, and 6.9 is the DBU. 7 is CP (J, 8 is data terminal equipment, 1
0 is a network management device (NMS), 31 is a test means, 32 is a backup release signal sending means (part), 61 is a line return means, 62 is a backup release signal receiving means (part), 31 is a test pattern generating part, 312 is an inspection section, and 611 is a switching control section. Reference numerals 612 and 613 refer to switches, b) a block diagram showing the configuration of the present invention;
4 Figure

Claims (1)

[Claims] A data communication system that includes a backup modem (5) and a line switching mechanism (6) and performs backup from the backup modem (5) through a backup line (2) in the event of a failure of the original line (1). , the modem (5) is backed up by the backup modem (5).
3) includes test means (31) for transmitting a test pattern signal and testing the line based on the signal received in return; and backup release signal transmitting means (32) for transmitting a signal for canceling backup; Mechanism (6)
In addition, it is equipped with a line return means (61) that loops back the original line interface, and a means (62) for detecting a backup release signal sent by an opposing modem through the original line. When switching to the line and performing backup, the line switching mechanism (6) puts the original line interface into a return loop state, sends a test pattern signal from the modem (3) connected to the original line, and receives the signal back. A backup method characterized in that the original line is tested using a signal, and if recovery is confirmed, a backup release signal is sent to cancel the backup and switch back to the original line.