JP2541099B2 - ISDN line detour method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN line detour system which uses an ISDN (Integrated Service Digital Network) line as a detour line in a failure of a private line in an electronic private branch exchange.

[0002]

2. Description of the Related Art It is known to use an ISDN line as a bypass line (see, for example, JP-A-3-96054 and JP-A-2-260895).

In the conventional detour system, two opposing stations perform their own detour control when the leased line fails.

[0004]

In the conventional detour system,
Since two opposite stations were performing detour control independently when the leased line failed, one station detected the failure and switched communication to the detour, but the other station could not detect the failure and the detour was used. There is a case where communication data is discarded because communication is not switched to another or due to a difference in switching time between two stations. Therefore, there is a problem that the call path may not be connected even if the call is bypassed, or the call being communicated may be disconnected even if the call path is connected, and a call may be required again.

[0005]

According to the present invention, the first and second stations normally communicate using a dedicated line, and when the dedicated line fails, the first and second stations make an ISDN line. In the ISDN line detour system in which communication is performed by using as a detour line, only one of the first and second stations is a master station that detects a fault in the leased line and outputs detour information to the ISDN line. Only the other one of the first and second stations is a slave station that receives the detour information from the ISDN line, and the master station detects a failure of the leased line and outputs the detour information to the ISDN line as user / user information. After that, the master station exchange CP that switches the communication from the leased line to the ISDN line
When the slave station has a U and receives the detour information according to the user-user information, the slave station performs communication from the leased line to the ISD.
An ISDN line detour system is provided which has a slave station exchange CPU for switching to an N line, and detours to an ISDN line without disconnecting a call in progress when a failure occurs in a leased line.

Further in accordance with the invention, the master station further comprises:
The slave station further includes a master station terminal and a master station switch that connects the master station terminal to one of the leased line and the ISDN line. The slave station further includes the slave station terminal and the slave station terminal for the leased line and the ISDN line. A master station switch CP having a slave station switch switch connected to one side.
The U normally controls the master station switch to connect the master station terminal to the leased line, detects a failure of the leased line, and uses the detour information as the IS / IS user information.
After outputting to the DN line, the master station switch is controlled to connect the master station terminal to the ISDN line, and the slave station switch CPU normally controls the slave station switch to connect the slave station terminal to the dedicated line. Then
When the detour information is received by the user / user information, the slave station switch is controlled to connect the slave station terminal to the ISDN line.
A DN line detour system can be obtained.

[0007]

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

FIG. 1 shows an embodiment of the present invention.

The station 1a includes an exchange CPU 2a, an exchange switch 8a, a terminal 5a, a leased line trunk 3a, and a detour IS.
It is composed of a DN trunk 4a. When connecting to the leased line 6, the terminal 5a and the leased line trunk 3a are connected by the exchange switch 8a, and when connecting to the ISDN network 7, the terminal 5a and the bypass ISDN trunk. 4a is connected by an exchange switch 8a. These controls are performed by the exchange CPU 2a.

The station 1b includes an exchange CPU 2b, an exchange switch 8b, a terminal 5b, a leased line trunk 3b, and a detour IS.
It comprises a DN trunk 4b. When connecting to the leased line 6, the terminal 5b and the leased line trunk 3b are connected by the exchange switch 8b, and when connecting to the ISDN network 7, the terminal 5b and the bypass ISDN trunk. 4b is connected by an exchange switch 8b. These controls are performed by the exchange CPU 2b.

Here, the station 1a is defined as a master station and the station 1b is defined as a slave station for the leased line 6. The master station 1a is a station that detects a failure and sends it to the ISDN line 7. The slave station 1b represents a station that receives a call from the ISDN line 7. The detour to the ISDN line 7 when the leased line fails is always transmitted from the master station 1a to the slave station 1b.

Next, the control procedure of the bypass system of the present invention will be described. The master station 1a and the slave station 1b are connected by a dedicated line 6. On the master station 1a side, the terminal 5a
It is connected to the leased line 6 via the intra-office speech path 9 and the leased line trunk 3a, and on the slave station 1b side, is connected from the leased line 6 to the terminal 5b through the leased line trunk 3b and the intra-station speech path 11 and is The terminal 5b is in a call through the leased line 6.

When a line failure occurs in the leased line 6 and the master station switch CPU 2a detects a failure in the leased line 6 from the leased line trunk 3a, the master station switch CPU 2a captures the detour ISDN trunk 4a and the master station A detour ISDN line 7 is connected from 1a to the slave station 1b. UUI from master station 1a to slave station 1b at line connection
(User / user information) is used to notify detour information. Since the detour to the ISDN line 7 is always transmitted from the master station 1a to the slave station 1b, the detour information includes information on the detour line to be switched by the master station 1a and the slave station 1b corresponding thereto. On the side of the slave station 1b by carrying the information of the bypass line on the side, the resource is hunted according to the information and switching to the bypass line is performed. As a result, the correspondence between the detour source and the detour destination is matched, and the switching timing is synchronized.

At this time, the master station 1a has the exchange CPU2.
a controls the switch 8a to connect the communication path 9 between the terminal 5a and the leased line trunk 3a to the terminal 5a and the bypass I.
The communication is switched to the communication path 10 (a detour line) between the SDN trunks 4a.

The slave station 1b receives the U from the master station 1a.
When the detour information is received by the UI (user / user information), the communication 11 between the terminal 5b and the leased line trunk 3b is transferred to the terminal 5b and the detour ISDN trunk 4b according to the detour information.
The communication is switched to the communication path 12 (a detour line) between them.

By the above control, the terminal 5a and the bypass IS
A call path is established through the DN trunk 4a, the ISDN network 7, the detour ISDN trunk 4b, and the terminal 5b, and a call in progress can be diverted without disconnection for a leased line failure.

[0017]

As described above, according to the present invention, since the switching timings of the two stations to the bypass line can be synchronized, the communication data is not discarded due to the switching timing shift. Further, when one station detects a failure and switches communication to the bypass, the other station cannot detect the failure and cannot switch communication to the bypass.
Therefore, a call in progress can be bypassed without disconnection, and a highly reliable network can be constructed.

[Brief description of drawings]

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

[Explanation of symbols]

 1a Master station 1b Slave station 2a, 2b Switch CPU 3a, 3b Dedicated line trunk 4a, 4b Detour ISDN trunk 5a, 5b Terminal 6 Dedicated line 7 ISDN line 8a, 8b Switch switch 9 Intra-station call path 10 Intra-station call path 11 Intra-station call Road 12 Internal call path

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Claims (2)

(57) [Claims] 1. The first and second stations normally communicate using a leased line, and when the leased line fails, the first and second stations communicate using an ISDN line as a bypass line. I
In the SDN line detour system, only one of the first and second stations is a master station that detects a fault in the leased line and outputs detour information to the ISDN line,
Only the other one of the first and second stations is a slave station that receives the detour information from the ISDN line, and the master station detects the failure of the leased line and sends the detour information to the ISDN line as user / user information. After outputting, the master station exchange CPU that switches the communication from the leased line to the ISDN line has a slave station switch that switches the communication from the leased line to the ISDN line when the slave station receives the detour information by the user / user information. It has a CPU and ISDN without disconnecting a call when a leased line failure occurs.
An ISDN line detour method characterized by making a detour to the line. 2. The master station further includes a master station terminal and a master station switch that connects the master station terminal to one of a leased line and an ISDN line, and the slave station further includes a slave station terminal. , A slave station switch that connects the slave station terminal to one of the leased line and the ISDN line, and the master station switch CPU normally controls the master station switch to connect the master station terminal to the leased line. Then, after detecting the failure of the leased line and outputting the detour information as the user / user information to the ISDN line, the master station switch is controlled to connect the master station terminal to the ISDN line, and the slave station switch CPU is Normally, the slave station switch is controlled to connect the slave station terminal to the dedicated line, and the detour information is controlled by the user / user information. The ISDN line bypass system according to claim 1, wherein, when the information is received, the slave station switch is controlled so as to connect the slave station terminal to the ISDN line.