JPH01137862A - Subscriber callback connecting system - Google Patents

Abstract

PURPOSE:To improve the service performance by not restoring a speech path set in an exchange even when an outgoing telephone set hooks on earlier so as to call back said caller telephone set with respect to a callback from the incoming telephone set. CONSTITUTION:A memory 10 storing callback information corresponding to each of line wire trunks 4, 14 is provided and the callback information is stored in the memory 10 corresponding to the line wire trunk 14 when the destination telephone number obtained through the line wire outgoing connection from the telephone set 1 accommodated in a private branch exchange A and a preset telephone number are coincident and when the telephone set 1 applies restoration during the connection of line wire origination, a call signal is sent to a telephone set 11 without interrupting the post equipment of the line wire trunk 14 and the state of the line wire origination connection is obtained by the reply of the telephone set 11. Since the callback is applied without any operation even when the outgoing telephone set hooks on earlier, the immediate correspondence is taken on emergency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a subscriber call-back connection system, particularly to a subscriber call-back connection system in a private branch exchange.

[Conventional technology]

Conventionally, if an outside line was made from an extension telephone of a private branch exchange and the extension telephone went on-hook before the incoming telephone went on-hook, the call path was severed and the connection between the central office trunk and the originating extension telephone was lost. , a busy tone is sent to the subscriber of the called telephone, and the called subscriber can only perform an on-hook recovery operation.

[Problem that the invention seeks to solve]

However, recently, services such as individual call reception and dial-in have become commonplace, and more and more private branch exchanges are being operated without installing a central office line relay stand. There is a drawback that the service quality deteriorates because calls are received on a telephone or the like.

Also, use the central office trunk to dial 110 (police) or 119.
When you call the number (fire department), if the extension telephone is restored before the office line trunk, the call may be returned from the office line trunk, but the call will arrive at the office line relay stand, and the call will be returned to the office line relay stand. If you are unable to obtain the telephone extension number and are unable to respond in an emergency, and if you use a trunk trunk to call the security telephone of another private branch exchange in the private branch exchange network, you may be unable to make a call. When a telephone goes on-hook, the security telephone has the disadvantage that it cannot tell which telephone it is connected to, and cannot call back.

An object of the present invention is to remember, when connecting from a private branch exchange to a specific telephone other than this exchange, that the connection is to a specific telephone until an on-hook message is transmitted from this specific telephone, so that the calling telephone To provide a subscriber call return connection system capable of calling a previous calling telephone in response to a call back from an incoming telephone without restoring the communication path set in the exchange even if the subscriber goes on-hook first.

[Means for solving problems]

In the subscriber call-back connection system of the present invention, a private branch exchange having external line trunks is provided with a memory for storing call-back information corresponding to each of the external line trunks, and an external line originating connection is made from a telephone housed in the private branch exchange. The called destination phone number obtained when the call is made is compared with the preset phone number, and when they match, the callback information is stored in the memory corresponding to the outside line trunk, and the phone is connected to the outside line while the phone is connected to the outside line. When a recovery operation is performed, a calling signal is sent to the telephone without disconnecting the rear end of the outside line trunk, and the telephone sets the outside line in a state of connection in response to a response.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram of a relay system according to an embodiment of the present invention, and shows a case where a network is constructed with two private branch exchanges A and B. In Figure 1, 1.11 is a telephone;
2 is a sender trunk that sends connection signals to private branch exchange B; 3 is a register trunk that receives dialing signals from telephone 1; 4.14 is a trunk trunk that connects private branch exchanges A and B; 5 is a ring signal to telephone 1. 6 is a tone trunk that sends out various signal tones, 7 is an outside line relay stand, 8 and 18 are call path networks that connect the plurality of telephones 1, the outside line relay stand 7, and the plurality of various trunks;
9.19 is a central control unit that controls the operation of the entire exchange,
10 is a storage device.

FIG. 2 is a layout diagram of the subscriber callback memory stored in the storage device 10. Each bit of 1 to 1 in FIG. set when the calling phone goes on-hook.

Next, to explain the connection and recovery operations when telephone 1 housed in private branch exchange A makes a call to a specific telephone 11 in private branch exchange B, register trunk 3 is captured by telephone 1 through a known outside line origination connection. Next, the outside line trunk 4 is activated, a connection signal is transmitted from the center trunk 2 to the outside line trunk 14 of the private branch exchange B, and the telephone 11 of the private branch exchange B is called. Next, the telephone 11 responds and becomes busy. At this time, the bit corresponding to the accommodation position of the outside line trunk 4 in the callback memory shown in FIG. 2 of the storage device 10 is set to 1'' and stored.

FIG. 3 is a flowchart when telephone 1 goes on-hook during a call.The explanation will be continued with reference to FIG. (Step ■) of reading the bit information corresponding to the accommodation position of the outside line trunk 4
. So, if this information is ``1'' (step ■) 1.
The ringer trunk 5 is connected to the on-hook telephone 1 and a ringing signal is sent (step ■), and the outside line trunk 5
The tone trunk 6 is connected to the tone trunk 6 to send out a ringback tone (step ■). Next, check whether the telephone 1 has answered within a certain period of time (Step 2). If it has answered, the telephone fil is connected to the outside line trunk 4 and a call is in progress (Step 2). If the information is "0" in step (2), the communication path m8 and the outside line trunk 4 are restored by a known restoration process (step (2)). Furthermore, if there is no response within a certain period of time in step (2), an incoming call is displayed on the outside line trunk 4 to which the telephone 11 is connected to the outside line relay board 7 using a known method (step (2)). Furthermore, when the outside line trunk 4 is restored, the bit corresponding to the outside line trunk 4 in the call return memory is cleared.

In the above embodiment, a call-back memory bit is set for each outside line trunk, but similar processing can be performed even if a call-back memory bit is provided for each subscriber's telephone.

Furthermore, in the above embodiment, the connection is made between private branch exchange A and private branch exchange B, but even if private branch exchange B is replaced by a public exchange, there is no problem at all.

〔Effect of the invention〕

As explained above, according to the present invention, in connection from a telephone housed in a private branch exchange to a specific telephone housed in an exchange other than this private branch exchange, even if the telephone that made the call goes off first. Since the call can be called back immediately, it has the effect of allowing immediate response in the event of an emergency.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a relay system according to an embodiment of the present invention, Fig. 2 is a layout diagram of an example of a subscriber call-back memory provided in a storage device of an exchange used in the present invention, and Fig. 3 is a diagram of the present invention. 1 is a flowchart of the invention. 1.11...Telephone, 2...Sender trunk, 3.
...Register trunk, 4.14...External line trunk,
5...Linger trunk, 6...Tone trunk, 7
. . . External line relay stand, 8. 18 . . . Communication path network, 9. 1 . . . Central control unit, 10 . . . Storage device.

Claims (1)

[Claims] In a private branch exchange having outside line trunks, a memory is provided to store call return information corresponding to each of the outside line trunks, and a memory is provided to store call return information corresponding to each of the outside line trunks, and a call destination telephone number obtained when an outside line outgoing connection is made from a telephone housed in the private branch exchange. When the telephone numbers are compared with a preset telephone number and they match, call return information is stored in the memory corresponding to the external line trunk, and when the telephone performs a recovery operation while the telephone is connected to the external line, the call return information is stored in the memory corresponding to the external line trunk. A subscriber call return connection system characterized in that a calling signal is sent to the telephone without disconnecting the subsequent line, and when the telephone responds, the outside line originating connection is established.