JP7234695B2 - automatic switchboard - Google Patents

Description

The present invention relates to an automatic exchange, and more particularly to a private branch exchange capable of giving a special number when making a call to a public network.

2. Description of the Related Art There is known a technique of notifying a caller's phone number (hereinafter referred to as caller's number) by displaying the caller's phone number on the called party's display device. Also, there is known a technique of designating whether or not to notify the caller number. For example, in many telephone companies, if there is no application from the user, it is set to be notified, and if there is an application, it is set to be non-notification. Further, for example, regardless of the presence or absence of the application, the calling party number is notified or not notified by dialing a specific number in addition to the telephone number when making a call. For example, in Japan, a caller ID non-notification special number (184) and a caller number notification special number (186) are generally used as special numbers added in front of the other party's telephone number.

For example, Patent Literature 1 discloses a communication terminal device that displays a caller's telephone number on a display device of a called party in response to notification of the telephone number from the caller. at least one display device for displaying the caller/receiver telephone number and the notification/non-notification state; and the notification/non-notification state of the display device. and means for switching the state of non-notification, and a function of dialing by giving a prefix number for designating notification/non-notification to the network according to the state of the memory means prior to the telephone number of the destination when calling. and clearly distinguishes whether or not a caller calls his/her telephone number by switching the status display of notification/non-notification when making a call.

JP-A-2000-165507

For example, when connecting to the public telephone network from a private telephone via a private branch exchange, if you want to set caller ID non-notification / notification, caller ID It was necessary to set in advance whether to always not notify or notify. In addition, even if the relevant settings were made in advance, if the user wanted to change the settings for each destination, the user of the telephone in the premises had to manually enter the number indicating the non-notification/notification of the caller ID. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above points. The purpose is to provide a private branch exchange.

An automatic exchange according to the present invention is a private branch exchange that performs extension switching operations and office line originating operations in accordance with exchange information data supplied via a subscriber line, wherein the exchange information data includes called information and station call information. and a caller number notification enable/disable command indicating whether or not the caller number is to be notified when the call is made on a local line, wherein the private branch exchange receives the caller number notification enable/disable command. and an exchange that performs an operation to make a call to a local line along with notification approval or disapproval according to the determination result of the notification approval/disapproval determination unit. A control unit and a holding unit that receives and holds the caller ID notification enable/disable command, and the notification enable/disable determining unit refers to the caller ID notification enable/disable command held in the holding unit. The determination is made as to whether or not notification is possible, and when the holding unit receives the caller ID notification permission/prohibition command, the holding unit transmits a signal indicating reception of the caller ID notification permission/prohibition command to the subscriber line. .

1 is a configuration diagram showing an overview of the configuration of a private branch telephone system 100 of an embodiment; FIG. It is a block diagram which shows the structure of PBX10 of an Example. 4 is a sequence diagram showing an example of an overview of operations performed in the private branch telephone system 100 of the embodiment; FIG. FIG. 4 is a flow diagram illustrating an example operational routine performed by an example PBX; FIG. 4 is a flow diagram illustrating an example operational routine performed by an example PBX; FIG. 4 is a flow diagram illustrating a variation of an operational routine performed by an example PBX;

Examples of the present invention will be described in detail below. In the following description and accompanying drawings, substantially the same or equivalent parts are denoted by the same reference numerals.

FIG. 1 is a configuration diagram showing an overview of the configuration of a private branch exchange (PBX) 10 including a private branch exchange (PBX) 10 according to an embodiment of an automatic exchange of the present invention. As shown in FIG. 1, the private telephone system 100 includes a PBX 10 and an extension telephone group 20 . Extension telephone group 20 is connected to PBX 10 . The PBX 10 is also connected to the public telephone network 30 .

The PBX 10 is a private branch exchange that exchanges between the extension telephone group 20 and the public telephone network 30 . In this embodiment, for example, the PBX 10 forms a communication path between telephones connected to the local subscriber lines by performing extension switching operations. Also, the PBX 10 forms a communication path between the extension telephone group 20 and the public telephone network 30 by performing office line switching operation.

The extension telephone group 20 is a plurality of extension telephones including an extension telephone 21 and an extension telephone 22 . Each extension telephone is connected to a local subscriber line. That is, each extension telephone is connected to the PBX 10 via a subscriber line. In this embodiment, each of the extension phones is a multifunction phone.

In this embodiment, each of the multifunction telephones included in the extension telephone group 20 is provided with one or a plurality of operation buttons in addition to ten keys. For example, each of the operation buttons is assigned functions such as redial, hold, and abbreviated dialing. In this embodiment, an operation button to which the function is assigned is called a "function key".

In addition, in this embodiment, one of the "function keys" is assigned a function indicating non-notification or notification of the caller number. As shown in FIG. 1, the extension telephone 21 has a dedicated non-notification key 21A indicating non-notification of the caller number and a notifying key 21B indicating notifying the caller number. Similarly, the extension telephone 22 has a non-notification key 22A and a notification key 22B.

The public telephone network 30 is a telecommunications line facility that is composed of exchanges and lines that connect them, and performs transmission switching for calls.

FIG. 2 is a block diagram showing the configuration of the PBX 10. As shown in FIG. The extension interface 11 is connected to the extension telephone group 20 . The extension interface 11 functions as an input/output interface for each external line, ie, a central office line and an extension line of the multifunction telephones included in the extension telephone group 20 .

The extension interface 11 is, for example, a line circuit, and transmits and receives information between the extension telephone group 20 and the PBX 10 . The line circuit converts, for example, an audio signal sent as an analog signal into a digital signal.

The external line interface 13 is connected to the public telephone network 30 . The external line interface 13 is an office line trunk which is a transmission interface circuit for connecting the PBX 10 to the public switched telephone network 30 . The external line interface 13 functions as an input/output interface for calls via the public telephone network 30 by the extension telephone group 20, that is, for external line calls.

The switch circuit 15 is a digital switch that forms a communication path between the extension interface 11 and the outside interface 13 . For example, switch circuit 15 includes a time switch. Also, for example, the switch circuit 15 may be configured by a combination of a space switch and a time switch.

The control unit 17 is, for example, a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 17 controls the extension interface 11 , the external interface 13 and the switch circuit 15 .

For example, the control unit 17 controls the extension interface 11 and the switch circuit 15 to perform an extension switching operation. Further, for example, the control unit 17 controls the extension line interface 11, the outside line interface 13 and the switch circuit 15 to perform office line switching operations including office line calling operations.

For example, the control unit 17 receives a signal indicating that a function key has been pressed from the extension telephone group 20, and receives and holds data indicating that the function key has been pressed. For example, the control unit 17 receives a signal transmitted when the non-notification dedicated key 21A indicating caller number non-notification or the notification dedicated key 21B indicating caller number notification is pressed, and data indicating, for example, until the end of the call.

Further, for example, the control unit 17 adds a predetermined specific number (special number) to the public network number of the called party according to the number dialed in the extension telephone group 20 during the office line call operation.

The storage unit 19 is a storage device such as a hard disk, flash memory, SSD (Solid State Drive), and RAM (Random Access Memory). The storage unit 19 appropriately stores data necessary for processing by the control unit 17 .

For example, the storage unit 19 stores table data in which a public network number to be used as a called number when making a call from the extension telephone group 20 and an abbreviated dial code having fewer digits than the public network number are associated with each other. is stored in advance. In addition, for example, the storage unit 19 stores a special number to which the public network number is additionally added when the local line calling operation is performed.

FIG. 3 is a sequence diagram showing an example of an overview of the operation performed by the private branch exchange (PBX) 10 and the private branch telephone 21, which is one of the multifunction telephones included in the extension telephone group 20, in the private branch telephone system 100. . As an example, the operation in the case where the user of the private telephone 21 makes a call on the office line will be described below. For example, when the handset of the private telephone 21 is picked up, the sequence shown in FIG. 3 is initiated.

When the sequence of FIG. 3 is started, a calling signal is sent from the private telephone 21 (step S101). The PBX 10 detects the call signal from the premises telephone 21 and sends a dial tone to the premises telephone 21 (step S102).

In step S102, a signal is sent to make a predetermined dial tone on the local telephone 21 to indicate that the PBX is ready to receive the signal from the local telephone 21. FIG. For example, the predetermined dial tone may be a dial tone indicating an extension call.

After that, when the dedicated non-notification key 21A or the dedicated notification key 21B (hereinafter also simply referred to as a dedicated key), which is a function key of the premises telephone 21, is pressed, a signal indicating that the dedicated key has been pressed is sent from the premises telephone 21. It is sent out (step S103). The signal indicating that the dedicated key has been pressed is, in other words, a caller number notification enable/disable command indicating whether or not the caller number is to be notified when the call is made on the office line.

The PBX 10 receives the signal and holds dedicated key ON data indicating that the dedicated key has been pressed (step S104). In step S104, the control unit 17 or the storage unit 19 of the PBX 10 functions as a holding unit that holds the caller ID notification enable/disable command.

After that, the PBX 10 sends a signal for instructing lighting of the dedicated key 21 to the private telephone 21 to the subscriber line (step S105). Upon receiving the signal for instructing lighting of the dedicated key, the private telephone 21 lights the lamp of the dedicated key (step S106). This allows the user to confirm that the PBX 10 has recognized that the dedicated key has been pressed, that is, that the caller number has been designated as non-notification or notification.

After that, when the user dials a number for calling by pressing the number buttons provided on the premises telephone 21, the premises telephone 21 transmits data indicating the dialed number (step S107). For example, when the user makes a call to a local line, the user dials the special number for calling the local line and the public network number of the terminal on the called side. In this case, in step S107, the private telephone 21 sends out a signal indicating the local line calling special number and the public network number.

The PBX 10 receives the data indicating the dial number, and if the dial number is included, determines whether or not it holds the dedicated key ON data (step S108). For example, when the PBX 10 receives the local line call special number, the PBX 10 may change the dial tone indicating the extension line call to the dial tone indicating the local line call and transmit the dial tone to the premises telephone 21 .

If the PBX 10 holds the dedicated key ON data, it adds a special number, which is a specific number indicating whether or not to notify the caller number, to the public network number (step S109), and makes a call to the local line (step S110).

In the above sequence, the PBX 10 does not have to transmit the signal instructing the lighting of the dedicated key 21 (step S105). Also, the private telephone 21 does not need to turn on the dedicated key lamp (step S106).

FIG. 4 is a flow chart showing a local line transmission routine RT1, which is an example of an operation routine executed by the control unit 17 of the PBX 10. As shown in FIG. For example, when the PBX 10 is powered on, the control unit 17 starts the office line transmission routine RT1.

After starting the office line calling routine RT1, the control unit 17 waits for a call signal from a multifunction phone included in the extension phone group 20 (step S201). For example, when the receiver of the local telephone 21 is picked up, the local telephone 21 sends out a call signal.

After executing step S201, the control unit 17 determines whether or not a calling signal has been received (step S202). If the controller 17 determines in step S202 that no call signal has been received, it returns to step S201 and waits for the call signal again.

When the control unit 17 determines in step S202 that it has received the call signal, it transmits a dial tone (step S203). In step S203, the control section 17 transmits a dial tone to the extension telephone that is transmitting the call signal. For example, when a call signal is received from the extension telephone 21 , a dial tone is transmitted to the extension telephone 21 . A case where a calling signal is received from the extension telephone 21 will be described below.

After executing step S203, the control unit 17 determines whether or not the dedicated key has been pressed (step S204). For example, in step S204, does the control unit 17 receive data indicating that the non-report key 21A indicating non-notification of the caller number or the notification-only key 21B indicating permission to notify the caller number has been pressed? determine whether or not

When the control unit 17 determines that the dedicated key has been pressed in step S204 (step S204: YES), it holds dedicated key ON data indicating that the dedicated key has been pressed (step S205). For example, in step S205, data indicating that the dedicated non-notification key 21A or the dedicated key 21B of the extension telephone 21 has been pressed is held.

After executing step S205, the control unit 17 transmits a dedicated key lighting instruction (step S206). In step S206, for example, the control unit 17 transmits to the extension telephone 21 a signal instructing lighting of a lamp provided on the non-notification dedicated key 21A or the notification dedicated key 21B.

If the controller 17 determines in step S204 that the dedicated key has not been pressed (step S204: NO), or after step S206 is executed, it determines whether or not dialing has started (step S207).

For example, in step S207, the control unit 17 determines that dialing has started when it receives a selection signal that is sent when the number buttons of the extension telephone 21 are pressed.

If the control unit 17 determines in step S207 that dialing has not started, it returns to step S204 and determines again whether or not the dedicated key has been pressed.

When the control unit 17 determines that dialing has started in step S207, it starts accepting dial numbers (step S208). For example, the dial number includes an office line calling special number serving as office line specifying information for specifying office line calling. Also, for example, the dial number includes a public network number as called information. Further, for example, the exchange information data may be an extension number as called information.

In this embodiment, for example, when the user of the extension telephone 21 starts dialing for calling a local line, the special number for calling the local line is accepted first. Also, in this embodiment, for example, when the user starts dialing for calling an extension, only the extension number is accepted.

The dial number is supplied to the PBX 10 via the subscriber's line together with the caller number notification enable/disable command, and serves as exchange information data used for the exchange operation. That is, the exchange information data includes office line designation information for designating a call to the office line, called information, and a caller number notification enable/disable command. In step S208, the control unit 17 functions as a receiving unit that receives exchange information data.

After executing step S208, the control unit 17 determines whether or not the call to the office line is specified (step S209). In step S209, for example, when a local line call special number, which is a number designating a local line call, is received, it is determined that a local line call has been designated. For example, a common number may be defined as a local line call special number in the premises where the extension operation is performed by the PBX 10 . In step S209, the control unit 17 functions as a station line determination unit that determines whether or not a station line call is specified.

It should be noted that the control unit 17 may change the type of dial tone and transmit it to the extension telephone 21, for example, when it is determined in step S209 that dialing from a central line has been specified. Further, for example, the control unit 17 may stop sending the dial tone when dialing of the public network number is started.

If the control unit 17 determines that the call is originating from a local line in step S209 (step S209: YES), it determines whether or not the dialing of the public network number of the called party is completed (step S210). For example, in step S209, it may be determined that dialing is completed when a number with a predetermined number of digits is received from the extension telephone 21. FIG.

If the control unit 17 determines in step S210 that dialing has not ended, it repeats step S210 and determines again whether or not dialing has ended.

When the control unit 17 determines in step S210 that dialing has ended, it ends accepting dial numbers (step S211).

After executing step S211, the control unit 17 determines whether or not the dedicated key is ON (step S212). For example, in step S212, it is determined whether or not data indicating that the non-notification key 21A or the notification key 21B has been pressed is stored.

For example, if data indicating that the dedicated non-notification key 21A has been pressed is held in step S205, it is determined that the dedicated key is ON in step S212. Further, for example, if it is determined in step S204 that the dedicated key is not pressed, it is determined in step S212 that the dedicated key is not ON.

In step S212, the control unit 17 functions as a notification propriety determination unit.

If the control unit 17 determines that the dedicated key is ON in step S212 (step S212: YES), it adds a special number indicating whether the caller ID can be notified to the public network number received from the extension telephone 21 (step S213). . In step S213, the control unit 17 adds a special number corresponding to the type of dedicated key to the public network number.

For example, when the non-notification dedicated key 21A is ON, "184" may be added as a special code for non-notification of the caller number in step S213. For example, when the notification-only key 21B is ON, "186" may be added as a special number for notification of the caller's number in step S213.

If the control unit 17 determines that the dedicated key is not ON in step S212 (step S212: NO) or after executing step S213, it performs the office line calling operation (step S214). In step S214, the control unit 17 determines whether or not to notify the public telephone network 30 of the caller number based on the public network number to which the caller number non-notification special number or the caller number notification special number is added in step S213, for example. Performs a station line transmission operation accompanied by

For example, in step S213, the control unit 17 uses a public network number to which "184" is added as a special number for calling party number non-notification or a public network number to which "186" is added as a special number for calling party number notification. Perform line transmission operation.

For example, if the control unit 17 determines in step S212 that the dedicated key is not ON, in step S214, it performs the office line calling operation without adding a special number indicating whether or not to notify the caller number.

In steps S213 and S214, the control unit 17 functions as an exchange control unit.

If the control unit 17 determines in step S209 that it is not a local line call (step S209: NO) or after executing step S214, it terminates this routine and repeats the local line call routine RT1.

As described above, according to the private telephone system 100 of this embodiment, the PBX 10 can receive the caller ID notification enable/disable command sent from the extension telephone 21 when the dedicated key is pressed. When the PBX 10 receives the caller number notification approval/disapproval command and the office line designation information designating the office line call, the PBX 10 can determine whether or not to notify the caller number based on this. By adding a special number indicating whether notification of the caller number is permitted or not based on the determination result of whether or not the notification of the caller number is permitted, it is possible to perform the operation of making a call to the local line with the permission of notification of the caller number. In other words, even if the user of the extension telephone 21 does not dial a special number for permission/inhibition of caller ID notification, the PBX 10 can automatically add the special number in response to the depression of the dedicated key.

As described above, according to the private telephone system 100 including the PBX 10 of the present embodiment, when making a call to a local line, the user can use the dedicated key provided on the extension telephone to notify the caller of the caller number. can be arbitrarily selected for each call. For example, even if it is set in advance whether or not to notify the caller number, it can be arbitrarily changed each time a call is made on a central line. Therefore, the user does not need to dial a special number for permission/inhibition of notification of the caller ID, and simply selects permission/prohibition of notification of the caller ID by a simple operation, and the special code for permission/inhibition of notification of the caller ID is automatically added. You can make outgoing calls.

In addition, the PBX 10 of this embodiment automatically adds a special number indicating whether or not notification of the caller ID is possible depending on whether or not the dedicated key is pressed in the private telephone system 100, that is, based on the caller ID notification permission/non-permission command. can do. For example, the maintenance manager of the private telephone system 100 does not need to set each extension telephone included in the extension telephone group 20 in advance to add a special number indicating whether or not to notify the caller ID. Therefore, according to the PBX 10 of this embodiment, the maintenance of the extension telephone group 20 in the private telephone system 100 becomes easy. Further, for example, it is not necessary to provide each extension telephone included in the extension telephone group 20 with a function of adding a special number indicating whether or not the caller ID can be notified. Therefore, the cost for installing the extension telephone group 20 or adding an extension telephone can be reduced.

Therefore, according to the PBX 10 of the present embodiment, it is possible to provide a private branch exchange that allows the user to select each time a call is made with a special number indicating whether or not to notify the caller number, and that facilitates maintenance management. can.

FIG. 6 is a flow chart showing a local line transmission routine RT2, which is a modification of the operation routine executed by the control unit 17 of the PBX 10. As shown in FIG. In FIG. 6, steps that are substantially the same as or equivalent to the office line transmission routine RT1 shown in FIGS. 4 and 5 are denoted by the same reference numerals.

After starting the office line transmission routine RT2, the control unit 17 executes steps S201 to S208 (see FIG. 4).

As shown in FIG. 6, after executing step S208, the control unit 17 determines the end of dialing (step S210), and ends the acceptance of exchange information data (step S211).

After executing step S211, the control unit 17 determines whether or not the received exchange information data includes a "fixed abbreviated dialing special number" and a "abbreviated dialing code" (step S301).

In this embodiment, for example, an "abbreviated dialing code" is a number with fewer digits than the public network number and is used in place of the public network number. According to the "abbreviated dialing code", the dialing operation by the user can be shortened compared to the case of dialing the public network number.

Also, in this embodiment, the "fixed abbreviated dialing special number" is dialed before the "abbreviated dialing code" when making a call to a local line. indicates

For example, the “fixed abbreviated dialing special number” may be transmitted to the control unit 17 by pressing a function key provided on the extension telephone 21 . For example, the extension telephone 21 may be provided with a “speed dial button” as a function key, and a “fixed speed dial calling special number” is transmitted to the control unit 17 .

When the control unit 17 determines that the exchange information data includes the "fixed abbreviated dialing special number" and the "abbreviated dialing code" (step S301: YES), the "fixed abbreviated dialing special number" and the "abbreviated dialing code" are It is converted into a "private line number" and a "public network number" (step S302).

In step S302, the control unit 17 refers to the storage unit 19 and reads out the "public network number" corresponding to the "abbreviated dialing code".

For example, the storage unit 19 stores an abbreviated number conversion table in which a plurality of public network numbers to be called by the local telephone system 100 and abbreviated dialing codes, which are numbers assigned to each of the public network numbers, are associated with each other. remembered.

For example, in step S302, the control unit 17 refers to the abbreviated number conversion table, reads out the "public network number" corresponding to the accepted "abbreviated dialing code", and converts the "abbreviated dialing code" to the "public network number". Convert to At step S302, the control unit 17 functions as an abbreviated number conversion unit.

When the control unit 17 determines that the exchange information data does not include the "fixed abbreviated dialing special number" and the "abbreviated dialing code" (step S301: NO), it determines whether or not a call to the central line is specified (step S209). As described above, for example, in step S209, it is determined whether or not the extension telephone 21 has dialed the special number for dialing the local line.

After execution of step S302 or when it is determined in step S209 that a local line call is designated (step S209: YES), the control unit 17 executes steps S212 to S214 in the same manner as in the local line call routine RT1. .

That is, the control unit 17 determines whether or not the dedicated key is ON (step S212), and if the dedicated key is ON, adds a special number indicating whether or not notification of the caller number is possible to the special number for calling the local line (step S213), A call to the office line is executed (step S214).

As described above, the PBX 10 of this embodiment determines whether or not to notify the caller number by executing the modified office line transmission routine RT2, and determines whether or not to notify the caller number based on the determination result. can be converted from an abbreviated dialing code, which has fewer digits than a normal called number, to a public network number, which is a normal called number. Then, by adding a special number indicating whether or not notification of the caller number can be made to the converted public network number, it is possible to perform a local line calling operation accompanied by whether or not the caller number can be notified.

That is, when the user of the extension telephone 21 simply presses a dedicated key for designating whether or not to notify the caller number and dials the abbreviated number, the PBX 10 automatically converts the abbreviated number to the called number, and A special number indicating whether or not the caller ID can be notified can be automatically added to the caller's number, and the operation of making a call to the office line can be performed.

Therefore, the maintenance manager does not need to make settings in advance for associating a special number for permission/prohibition of caller ID notification with the abbreviated dialing code. Therefore, it is possible to provide a private branch exchange that reduces the complexity of the operations of the user and maintenance manager, increases convenience, and facilitates maintenance and management, regarding outgoing calls accompanied by a special number indicating whether or not notification of the caller's number can be made.

In the above embodiment and modification, an example was explained in which the extension telephone 21 was provided with the non-notification key 21A indicating non-notification of the caller number and the notifying key 21B indicating notifying the caller number. Not limited. For example, the extension telephone 21 may have either a non-notification dedicated key 21A or a notification dedicated key 21B. The PBX 10 may be configured to be able to receive a signal when either the non-notification dedicated key 21A or the notification dedicated key 21B is pressed as a caller ID notification enable/disable command. Then, it is only necessary to be configured so that the special number indicating whether or not to notify the caller number is automatically added according to the notification permission/refusal command, and the office line calling operation can be performed.

The configurations in the above-described embodiments are merely examples, and can be changed as appropriate according to the application.

100 private telephone system 10 private branch exchange 11 extension line interface 13 outside line interface 15 switch circuit 17 control unit 19 storage unit 20 extension telephone groups 21, 22 extension telephones 21A, 22A non-notification dedicated keys 21B, 22B notification dedicated key 30 public telephone network

Claims (3)

A private branch exchange that performs an extension switching operation and an office line calling operation according to exchange information data supplied via a subscriber line,
The exchange information data includes called information, office line designation information that specifies whether or not the call is made on a local line, and a caller number notification permission/prohibition command that indicates whether or not the caller number is to be notified when the call is made on the office line,
the private branch exchange, a notification propriety determination unit that determines whether or not notification of the caller number is permitted based on the caller number notification propriety command;
a switching control unit that carries out a local line transmission operation accompanied by notification propriety according to the judgment result of the notification propriety judgment unit;
a holding unit that receives and holds the caller ID notification enable/disable command;
The notification enable/disable determining unit refers to the caller ID notification enable/disable command held in the holding unit and performs the notification enable/disable decision,
A private branch exchange according to claim 1, wherein said holding unit, when receiving said caller number notification enable/disable command, sends a signal indicating reception of said caller number notification enable/disable command to said subscriber line. a station line determination unit that determines whether or not the station line transmission is designated by the station line designation information;
When it is determined that the call to the office line is designated, the exchange control unit is configured to switch the call to the office line based on the called information and a specific number indicating whether or not the notification is permitted according to the determination result of the notification permission determination unit. 2. The private branch exchange according to claim 1, wherein the operation of making a call is performed. the called information includes an abbreviated number corresponding to the called number;
the private branch exchange has an abbreviated number conversion unit that converts the abbreviated number to the called number;
3. The private branch exchange according to claim 1, wherein said exchange control unit carries out a local line transmission operation with said called number converted by said abbreviated number conversion unit.

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