JPH0335686A - Trunk responding system for private automatic branch exchange - Google Patents

Abstract

PURPOSE:To omit troublesome operation by calling a second extension telephone set without once recovering connection when a caller on a station side meets the busy state of a first extension telephone set. CONSTITUTION:When an extension is occupied, an ISDN terminal 10 sens the dial figures of the second extension telephone set 5 through an I interface while maintaining the state of busy tone connection without once recovering the connection. The dial figures are detected by a central control unit 2 through a central office line 6. The central control unit 2 reads the connecting state of the central office line 6 from a connecting state memory in a main storage device 3, and identifies that the central office line 6 is presently under the busy tone connection. Based on this identification, main switch 100 is controlled and the busy tone connection is recovered. Then, the central office line 6 is connected with a register trunk 7. Thus, the dial figures of the second extension telephone set are received and accumulated. Afterwards, based on these dial figures, are incoming processing is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to a central office line response system that is applied to a private automatic branch exchange, and more specifically, to a first extension telephone in response to an incoming call using a dial-in system from an l8DN terminal. is busy, the second extension 1! This relates to a method of calling a telephone.

(Prior Art) Conventionally, responses to incoming calls from this type of central office line have been carried out using the following procedure.

When the caller on the central office side calls the first extension telephone housed in the private branch exchange using the PBX dial-in method, if the first internal IT telephone is busy, in order to call the second extension telephone, After confirming the busy tone that identifies that the first extension telephone is busy, the first extension telephone is restored. Then, it was necessary to make a call to the second extension telephone again.

(Problem to be Solved by the Invention) In the conventional central office line response system, when a call is made to the second extension telephone and it is confirmed that the first extension telephone is busy, the call is returned to normal. After that, perform the same operation on the second extension phone.

This method has the drawback of placing a large operational burden on the caller at one station because he or she has to make a call.

The object of the present invention is to overcome the above-mentioned drawbacks.

If the central caller encounters the first extension telephone being busy,
- To provide a central office line response system for calling a private automatic branch exchange, which allows a second extension telephone to be called without having to be restored, and which can omit operational complexity.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the central office line response system applied to the private automatic branch exchange according to the present invention is connected to a public network corresponding to 15L)N, and provides Pl$X dial-in service. (on a private branch exchange where possible).

The ISDN terminal of the public network makes a call using the PBX dial-in method, and calls the first ISDN terminal accommodated in the private branch exchange.
calls an extension and is busy as a result,
■ Rather than sending the dialed digits of the second extension telephone via the interface, the private branch exchange
When the dialed digits of the extension telephone are detected, the connection status memory 1! in the main storage device is detected. :Readout 1 A means for identifying that a busy tone connection is in progress and restoring the busy tone connection, and a means for receiving and storing dialed digits of the second extension telephone at the same time as the busy tone connection is restored. However, it is configured to perform incoming call processing based on the dialed digits of the second extension telephone.

(Example) Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a central line response system applied to a private automatic branch exchange according to the present invention. A main storage device 3 having a connection state memory indicating the connection state of each terminal is connected to the central control device 2. The central control unit 2 includes a main switch 1, a first extension telephone 4. Second extension telephone 5)
It also controls the central office line trunk 6 and the register trunk 7. Further, the ISDN terminal IO is accommodated in the public exchange 8 via the public network 9 compatible with I8DN. l81)N
The terminal 10 has a first extension telephone 4. Not only is it possible to communicate with the second extension telephone 5 via the above-mentioned switching system.

Through the interface, it is possible to send dialed digits arbitrarily even in the busy tone connection state.

between the public exchange 8 and the private branch exchange system.

PBX dial-in service can be provided to the l8DN terminal 10.

Regarding the configuration of the public network, public exchange@, and private automatic branch exchange described above, when an I8D is encountered while the first extension telephone 4 is busy,
- Consider a case where the terminal 10 calls the second extension telephone 5.

Depending on the PBX dial-in method, the l8DN terminal 10 is 1
Busy first extension telephone 4f: When called, a busy tone is sent back through the one-busy tone connection, thereby making it possible to tell t-m that the extension is busy. At this time, l8DN terminal l
O once had i in the state of audio connection during one call without restoring it.
At t, the dialed digits of the second extension telephone 5 are sent out via the 1 interface.

The dialed numbers are sent to the central controller 2 via the central office trunk 6.
detected. The central control device 2 reads out the connection state of the central office line trunk 6 from the connection state memory in the main storage device 3.
It is identified that the central office line trunk 6 is currently connected to one busy tone. Based on this, the main switch 100 is controlled to restore the busy tone connection and connect the office line trunk 6 and the register trunk 7. As a result, the dialed digits of the second extension telephone 5 are received and stored.

Thereafter, incoming call processing is performed based on this dialed number.

If telephone 5 of 1IE2 is also busy, 3rd. Incoming call processing is performed for the fourth extension telephone using the same procedure.

(Effects of the Invention) As explained above, the present invention provides a method for transmitting data from the caller on the central office side during the busy tone connection when the caller in the ISDN compatible public network encounters the first extension telephone being busy. can detect and receive the dialed digits of the second extension telephone. Based on this, incoming call processing can be performed immediately. Therefore, according to the present invention, even if the first extension telephone is busy, there is no need for the caller on the central office side to once recover and then call again; This has the effect that by inputting a key on the interface, the second extension telephone can be called subsequently, thereby improving the service to the caller on the first station side.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a central line response system applied to a private automatic branch exchange according to the present invention. 1... Main switch 2... Central control device 3...
Main storage device 4... First extension terminal 5... Second extension terminal 6... Office line trunk 7... Register trunk 8... NTT station 9... Public network 10 compatible with l8DN ...Engineer SDN terminal in public network

Claims (1)

[Claims] In a private branch exchange that is connected to a public network compatible with ISDN and is capable of providing PBX dial-in service, the ISDN terminal of the public network makes a call using the PBX dial-in method, and calls the private branch exchange accommodated in the private branch exchange. When the telephone extension number 1 is called and the telephone extension number 1 is busy as a result, the dialed digits of the second telephone extension telephone number are sent out through the interface number 1, and the private branch exchange transmits the dialed digits of the second telephone extension telephone number. means for reading a connection state memory in a main storage device when detecting the connection state, identifying that the busy tone connection is in progress, and restoring the busy tone connection; and means for restoring the busy tone connection while restoring the busy tone connection; A central office line response system in a private automatic branch exchange, comprising means for receiving and storing dialed digits of a telephone, and performs incoming call processing based on the dialed digits of the second extension telephone.