JPH057200A - Isdn compatible line changeover device - Google Patents

Abstract

PURPOSE:To prevent speed decrease of a line backup by using all of two sets of B channels of an ISDN so as to send a data when a network is backed up. CONSTITUTION:When it is discriminated that a hindrance takes place in the communication, the operator uses the ISDN to make operation for backup to control a control section 5 and an ISDN interface 6 for calling. When the control section 5 confirms the notice of the end of changeover from a remote side main device to an ISDN connection DTE, the control section 5 controls a changeover section 3 so that a DTE digital interface 2 and a signal distribution collection section 7 are connected. The collection section 7 according to a command from the control section 5 collects the two channel signals from the interface 6 into the digital data signal and the digital control signal and outputs the result to the DTE. The interface 6 converts the 2 channel signals from the section 7 and outputs the converted signal to the ISDN and converts the input signal from the ISDN into the 2 channel signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN-compatible line switching device, and more particularly to a line switching device for backing up a network via ISDN when a working network fails when performing data communication using a leased line line terminating device. ..

[0002]

2. Description of the Related Art Conventionally, as a network backup system, there is a system in which a line is switched to the ISDN side in response to the occurrence of a failure in an active dedicated line and a network backup is performed via this ISDN.

FIG. 3 shows a system configuration of an ISDN-compatible line switching device for performing such network backup. This line switching device 1 is a data terminal device (DT
D) side interface 2 connected to E) 8, DCE side interface 4 connected to leased line circuit terminator (DCE) 9, and DT in response to control from control unit 5.
A switching unit 3 for selectively connecting the E-side interface 2 to either the DCE-side interface 4 or the ISDN interface 6 is included.

Under the control of the control unit 5, the ISDN interface 6 converts the digital data and the digital control signal from the DTE 8 and sends them to the ISDN, and the input signal from the ISDN is converted into the digital data and the digital control signal. It is converted and sent to the DTE side. In addition, this ISDN interface 6
Performs ISDN outgoing call and automatic incoming call control under the control of the control unit 5 which operates based on information from the outside.

In such a conventional line switching device, the IS
DN No. 1 and No. Only one of the two B channels is used for line backup. Therefore, when performing line backup of a dedicated line line terminator that is transmitted at a data transmission speed that is equal to or higher than the data transmission speed that one B-tunnel can transmit, the transmission speed is
It is necessary to reduce the data transmission rate of the channel.

Therefore, there is a limit to the transmission speed that can be backed up, and since all two B channels of ISDN are not used, there is a drawback that the transmission band of ISDN is not effectively used.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ISDN-compatible line switching device that effectively utilizes the ISDN transmission band and does not need to reduce the data transmission rate.

[0008]

An ISDN-compatible line switching device according to the present invention comprises a data terminal side interface, a leased line line terminating device side interface, an ISDN interface for controlling ISDN calling and automatic call reception, and the data terminal. Switching means for selectively connecting the side interface to either the dedicated line terminator side interface or the ISDN interface, and when the data terminal side interface is connected to the ISDN interface by the switching means, Data signals and control signals from the data terminal side interface are set to ISDN 2
Means for distributing to one B channel and supplying to the ISDN interface, and for converging signals of two B channels from the ISDN interface and supplying to the data terminal side interface.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a system configuration diagram of an embodiment of the present invention, and the same portions as those in FIG. 3 are designated by the same reference numerals. According to the present invention, the B channel of ISDN is No. at the time of backup by ISDN. 1 and No. In consideration of the fact that there are two channels, 2 and 2, both are used for signal transmission.

Therefore, in this embodiment, as shown in FIG.
A converging unit 7 is newly provided for signal distribution, and digital data and digital control signals from the DTE side interface 2 are distributed and controlled to two B channels so as to have the format shown in FIG. The input signal (the signal of the format shown in FIG. 2) is focused on the digital data and the digital control signal.

In FIG. 2, F is a frame bit, and the data transmission rate of each B channel is 64 Kbps. Other configurations are the same as those of the conventional example shown in FIG.

The operation of the embodiment of the present invention will be described below. First, a case where the ISDN-compatible line switching device 1 is a local calling side will be described.

When it is judged that some trouble has occurred in the data communication on the dedicated line and the communication is hindered, the operator operates the local side apparatus to perform backup using the ISDN. Control unit 5 of this device, ISDN
The interface 6 is controlled to make a call.

Upon confirming the notification from the remote side device that the ISDN connection / DTE switching has been completed, the control unit 5 of this device determines that the DTE side digital interface 2 and the signal distribution / focusing unit 7 are in the connected state. Switching unit 3
To control.

The signal distribution / focusing unit 7 distributes the digital data signal and the digital control signal from the DTE side to a combination signal of the digital data signal and the digital control signal and a two-channel signal of only the digital data signal according to the instruction of the control unit 5. To the ISDN interface 6,
Also, the two-channel signals from the ISDN interface 6 are converged into a digital data signal and a digital control signal and output to the DTE side, respectively.

The ISDN interface 6 converts the two-channel signal from the signal distribution / focusing section 7 into an ISDN signal and outputs the input signal from the ISDN into a two-channel signal and outputs the signal into the signal distribution / focusing section 7. .. After that ISD
Data communication is performed by the backup network using N.

When the backup cancel instruction is received by the external operation, the control unit 5 of this apparatus interrupts the data communication, and the IS
The DN interface unit 6 is controlled to notify the remote side device of the backup cancellation instruction via the ISDN. After that, when confirming the notification of the completion of the backup release from the remote side device via the ISDN, the switching unit 3 is controlled to connect the DCE side digital interface 4 and the DTE side digital interface 2. Further ISD
The N interface 6 is controlled to disconnect the ISDN and the backup release is completed. After that, it returns to the data communication using the dedicated line.

Next, the operation of the remote called side will be described. When the control section 5 of the remote side apparatus confirms the incoming call from the ISDN interface 6 in response to the call from the local side apparatus, the DTE side digital interface 2 and the signal distribution / convergence section 7 are switched to the connected state. Control part 3. Since the operation of the signal distribution / focusing unit 7 is as described above, the description thereof is omitted here. When the switching is completed, the ISDN interface 6 is controlled to notify the local side device that the switching is completed. After that, data communication is performed by the backup network using ISDN.

Upon receiving the backup release notification from the local side device, the control part 5 of the remote side device interrupts the data communication, controls the switching part 3 and controls the DCE side digital interface 4 and the DTE side digital interface 2.
And connect. Further, after controlling the ISDN interface unit 6 to notify the local side device of the backup cancellation, the ISDN is disconnected and the backup cancellation is completed.
After that, it returns to the data communication using the dedicated line.

[0021]

As described above, according to the present invention, the ISDN
ISD when performing network backup via
Since data transmission is performed by using all two B channels of N, data is transmitted at a speed equal to or higher than the data transmission rate per one ISDN B channel. There is an effect that the line terminating device for the leased line can be backed up without speeding down.

[Brief description of drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing a data format example when two B channels of ISDN are used as backups.

FIG. 3 is a system block diagram of a conventional ISDN-compatible line switching device.

[Explanation of symbols]

 2 DTE side interface 3 Switching section 4 DCE side interface 5 Control section 6 ISDN interface 7 Signal distribution / focusing section 8 DTE 9 DCE

Claims (1)

Claim: What is claimed is: 1. A data terminal-side interface, a leased-line line-terminating-device-side interface, and an ISDN interface for performing ISDN outgoing call and automatic incoming call control.
Switching means for selectively connecting the data terminal side interface to either the leased line line terminating equipment side interface or the ISDN interface, and the data terminal side interface is configured to change the data terminal side interface to the I
When connected to the SDN interface, the data signal and control signal from the data terminal side interface are I
Means for distributing the signals to the two B channels of SDN and supplying the signals to the ISDN interface, and for converging signals of the two B channels from the ISDN interface and supplying the signals to the data terminal side interface. ISDN compatible line switching device.