JPH0453159B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an additional dialing system for incoming central office line calls in an automatic private branch exchange.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic private branch exchange in which only a specific caller is permitted to make additional dials and directly calls a called party who is an extension subscriber, and in other cases the call is terminated at a central office relay stand. line to provide an additional dialing method for incoming calls.

In order to achieve the object of the present invention, the configuration of the present invention is such that in an automatic private branch exchange that accommodates a central office line capable of additional dialing, when a call is received from the central office line, the number dialed by the central office line subscriber prior to additional dialing is It is determined whether the special number matches a pre-stored special number, and if it matches, additional dialing from the central office line subscriber is permitted and the called party is called, and if it does not match, the central telephone relay stand This will allow you to receive a call.

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

FIG. 1 is a relay system diagram showing an embodiment of the additional dialing system for incoming calls on central office lines according to the present invention. In the figure, 10 is an extension subscriber accommodated in an automatic private branch exchange. 13 is an exchange switch of an automatic private branch exchange. 17 is a central office line, and 14 is a central office line trunk. 12 is a register that receives and counts additional dials. Reference numeral 11 denotes an office line relay board, 15 an intra-office connection trunk for connection of inter-extension calls, and 16 an outgoing register trunk for outgoing connection from the extension to the office line.
18 is a central control unit, and 19 is a storage unit.

When the central office line trunk 14 detects an incoming call on the central office line 17, the central control unit 18
4 and the register 12 housed on the extension side are connected via the path a of the exchange switch 13. As a result, it becomes possible to receive additional dials.

The format of the additional dial consists of a predetermined path number specific to this automatic private branch exchange and an extension number next to this path number, and this path number is stored in the storage section 19 in advance.

Next, in this embodiment, when the telephone on the central office line 17 side is a push-button telephone, in other words, when an additional dial is sent as a PB signal after receiving a call, the register 12 receives this and the central control unit 18 receives the additional dial. Send dial code. The central control unit 18 checks the received dial code with the pass number for additional dialing when receiving a central office line call, which is stored in advance in the storage unit 19, and if they match, allows the additional dialing and corresponds to the extension number. call the extension subscriber 10. Here, when the extension subscriber 10 responds, the central office line trunk 14 and the extension subscriber 10 are connected via path b of the exchange switch. In addition, if the pass number does not match, the central control unit 18
does not allow additional dialing and uses central office trunk 14.
is connected to the office line relay board 11 via route c, and the office line is received at the office line relay board 11 as before. As a result, in response to the response of the operator at the central office line relay stand 11, the central office line subscriber speaks with the operator, and connection to the desired extension subscriber is achieved.

Note that if there is no additional dial from the central office line subscriber within a certain period of time (for example, about 10 seconds) after connecting the register 12 via route a, the central control unit 18 to receive a call.

In this way, a pass number is provided for additional dialing, and additional dialing is permitted only when the number dialed by the central office line subscriber matches this pass number, so additional dialing is only required for a limited number of incoming central office line calls. An extension connection is made by dialing, and in other cases, the call is received at a central office relay stand and an extension connection is made by the operator.

In the above embodiment, the additional dialing when receiving a call on the central office line is limited to the case of a PB signal, but the present invention can also be applied to the case of a DP signal by modifying the exchange at the central office side. Further, in the same embodiment, the relay stand system has been described, but the present invention is not limited to this and can be similarly applied to a distributed relay stand system.

Furthermore, in order to prevent all charges from being made to the automatic private branch exchange when it is possible to make a call to the central office line again by additional dialing after receiving a call to the central office line, in this system, the above-mentioned pass number is used as a secret code and a specific It is preferable to use a code known only to the caller, or to change the pass number sequentially depending on the date and time.

As explained above, according to the present invention, by adding a special number to the additional dialing when a call arrives on the central office line, only a specific central office line subscriber is allowed to make additional dialing, and therefore it can be distinguished from general incoming calls. ,Also,
In other cases, it has the feature that it is connected to the extension line via the operator at the central office relay stand, as in the past.

[Brief explanation of the drawing]

FIG. 1 is a relay system diagram showing an embodiment of the additional dialing system for incoming calls on central office lines according to the present invention. 10...extension subscriber, 11...office line relay stand, 1
2...Register, 13...Exchange switch, 14...
... Office line trunk, 15... Local office connection trunk,
16... Calling register trunk, 17... Office line,
18...Central control unit, 19...Storage unit, a,
b, c...route.

Claims (1)

[Claims] 1. In an automatic private branch exchange that accommodates a central office line capable of additional dialing, when a central office line call arrives, it is determined whether the number dialed by the central office line subscriber matches a pre-stored special number before additional dialing. and if they match, additional dialing from the central office line subscriber is permitted and the called party is called, and if they do not match, the call is terminated at the central office line relay stand. method.