KR950003725B1 - Call-serving method of pabx - Google Patents

Abstract

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Description

Call service method of private exchange connected to DISA line

1 is a block diagram of a general private exchange system.

2 is a flowchart of an extension call service according to the present invention.

3 is a flow chart of a trunk line call service according to the present invention.

* Explanation of symbols for main parts of the drawings

101: central processing unit 102: memory

103: interface circuit 104: switch circuit

105: extension circuit 106: trunk line circuit

107: DTMF Receiving Circuit 108: DTMF Receiving Circuit

109: tone generating circuit 111: extension subscriber

The present invention relates to a private exchange system, and in particular, when a trunk line connected to a DISA (Direct Inward System Access: DISA) line is received, the external subscriber continuously provides an internal call or a trunk line call while the call line is not blocked. It relates to a method of adjusting the talk time according to the needs of the.

Conventionally, when an external CO line subscriber connected to a DISA line dials a counterpart private exchange to receive a CO line, when the ring back tone rings for a predetermined time and a dial tone is generated, the external subscriber may make an extension or CO line call by dialing a specified password. At this time, the call was made by dialing the extension number directly for the internal call, dialing the CO line access ID for the call, and then pressing the external dialing number.

As such, the conventional CO line subscriber connected to the DISA line can only talk for a specified time, and there is a problem that the extension subscriber of the key phone cannot call back with another extension subscriber after the call is terminated.

It is an object of the present invention to provide a method for continuously talking with a plurality of subscribers of a private exchange in a private exchange system when a trunk line connected to a DISA line is received without interruption of a communication path.

Another object of the present invention is to provide a method for improving a call service by adjusting a call time according to a situation when a CO line connected to a DISA line is received in a private exchange system.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a private exchange system according to the present invention, wherein the central processing unit 101 controls the overall operation of the system so that various functional services can be processed except for the formation of a call path. The memory 101 stores a program for storing basic calls and various functions of the central processing unit 101 and initial service data, and under program control under the control of the central processing unit 10. It consists of RAM which temporarily stores the generated data.

An interface circuit 103 is connected between the CPU 101 and each component of the system, and interfaces each data and signals generated during the exchange function. The switch circuit 104 is designated under a control of the central processing unit 101 to exchange various tone signals, dialing data and voice data. The internal circuit 105 is connected between the switch circuit 104 and the internal subscriber 111 and the like, and forms an internal call loop under the control of the central processing unit 101, and calls the internal subscriber 111. At the same time, the various state signals and voice signals are interfaced between the subscribers 111 of the switch circuit 104. The general trunk line circuit 106 is connected between the switch circuit 104 and the public telephone network PSTN, and under the control of the central processing unit 101, the trunk line lines are formed to form a trunk line call loop and various state signals coming from the trunk line. And a voice signal to the switch circuit 104, and outputs a signal and a voice signal output from the switch circuit 104 to the trunk line.

A DTMF receiving circuit 107 is connected to the switch circuit 104, converts the received dialing signal into digital data and sends it to the central processing unit 101. The DTMF transmission circuit 108 is connected to the switch circuit 104 and converts the dialing signal transmitted to the DTMF signal and outputs it to the switch circuit 104. The tone generating circuit 109 is connected to the switch circuit 104, and a corresponding tone signal is designated and sent to the switch circuit 104 under the control of the central processing unit 101. The ring generating circuit 110 is connected to the switch circuit 104 to supply a ring signal to the station subscriber circuit 105.

Such a private exchange system may be a key telephone system or a general private exchange (PABX).

2 is a flow chart of an extension call method according to the present invention, when a call is received from an external subscriber, transmitting a dial tone to an external subscriber, and transmitting the dial tone to the external subscriber in the dial tone transmission process. Receiving the extension number dialed from the terminal and checking the callable state of the subscriber, and if the call is not available in the call state checking process, takes a switch key (*) from an external subscriber and returns to the dialtone transmission process. A process of inputting an extension number to be redialed, a process of establishing a call path in the process of checking a call availability state, switching an internal call according to a request of an external subscriber, and establishing a call path in the process of checking a call state Check the end time and adjust the extension time according to the needs of external subscribers It made up of the process.

3 is a flow chart of a trunk line call method according to the present invention, when a trunk line is received from an external subscriber, a process of transmitting a dial tone to an external subscriber, and after dialing out the dial tone transmission process, dialing from an external subscriber. And inputting the CO line access ID, which is inputted, during the CO line access ID input process, after transmitting the CO line access ID, transmitting a switching sound to an external subscriber and inputting a password for a CO line call; Entering a password and connecting a CO line with an external subscriber to form a CO line call, forming a CO line call during the CO line forming process, and dialing a different CO line number when a switch key (*) is entered to make a call with another CO line If a switch key (*) is not input after forming a trunk line call in the process of connecting the furnaces and forming the trunk line call, Checking the end time of the call consists of adjusting the call time according to the request of the external subscriber.

One embodiment of the present invention based on the above-described configuration will be described in detail with reference to FIGS.

First, in the flowchart of FIG. 2, when the CO line connected to the DISA line of the CO line 106 is received from an external subscriber, the dial generated from the tone generating circuit 109 in step 2a is shown. The tone is switched in the switch circuit 104 to send a dial tone to the external subscriber (step 2b). In the step (2b), when the external subscriber who has received the dial tone dials the desired extension number, the extension number is received through the DTMF receiving circuit 107. At this time, the central processing unit 101 checks the available state of the extension subscriber corresponding to the received extension number through the extension circuit 105. In other words, check whether the ring signal continues to ring for a certain time in step (2c), whether the extension subscriber is busy in step (2d), call rejection state (DND) in step (2e), or whether an unused extension number is entered. If any of the above occurs in the steps (2c)-(2f), step (2g) is performed. In step (2g), it is checked whether the switch key (*) signal is dialed through the DTMF receiving circuit 107 from the external subscriber and is input. When the switch key signal is input, the process returns to step (2a) and transmits the dial tone again. Try dialing. However, if no case occurs in steps (2c) to (2f), a call is made with the extension subscriber in step (2h).

As described above, when the user wants to switch a call with an external subscriber and another extension subscriber while the call path is formed and the call is made, the switch key (*) is dialed in step 2i. If the switching key is inputted after checking whether it is input, the process returns to step 2a to dial another extension subscriber to form a call. However, if the switch key (*) is not input from the external subscriber in step (2i), it is determined whether the call termination time set in step (2j) is reached. If the call termination time does not reach, the call continues with the extension subscriber in step (2j). do.

However, if the call termination time is reached in step (2j), a warning sound is sent to an external subscriber in step (2k) and step (2l) is performed. In the step (2l), it is checked whether any digit set by the external subscriber through the DTMF receiving circuit 107 is dialed and inputted, and if the digit is not input, the call is terminated by blocking the extension. However, if a digit is input in step (2L), the call time is extended by the set unit time in step (2m), and the call returns to step (2h) to continue the call. When you want to switch the call with and repeat the steps (2h)-(2m).

In addition, in the flowchart of FIG. 3, a method of making an external subscriber make a trunk line call through a DISA line of a private exchange as shown in FIG. 1 is performed when a trunk line connected to a DISA line of a trunk line circuit 106 is received from an external subscriber (3a). The central processing unit 101 transmits the dial tone generated by the tone generating circuit 109 to an external subscriber.

The external subscriber who receives the dial tone dials the CO line access ID 9 or 80-89 for the CO line call. At this time, the CO line access ID dialed from the external subscriber in step (3b) is input through the DTMF receiving circuit 107, and the switching sound is transmitted to the external subscriber in step (3c). The external subscriber who has received the diversion tone dials a password for a trunk line call and inputs the password through the DTMF receiving circuit 107 in step 3d. In step 3l, if the input password matches or not, it checks whether or not the call is terminated in step 3o. However, if the password inputted from the external subscriber in step (3l) matches the specified password, in step (3f), the external subscriber connects the CO line. When the external subscriber and the CO line are connected in step (3f), the dial-up dial tone is sent to the external subscriber. At this time, the external subscriber dials the desired CO number in step (3g). Form. When the CO line is formed in step (3h) and the call is made, the external subscriber dials the switch key (*) when he / she wants to talk to another CO line subscriber. When the check key (*) is inputted, the process returns to step (3f) to establish a call by dialing another CO line subscriber in step (3g) (3h).

However, if the switch key (*) is not input from the external subscriber in step (3l), step (3j) is performed. In step (3j), it is checked whether the set call end time is reached, and when the call end time is not reached, the trunk line call is continued in step (3k). However, if the call termination time is reached in step (3j), a warning sound is sent to an external subscriber in step (3k) and step (3l) is performed. In step (3l), it is checked whether any digit set by the external subscriber through the DTMF receiving circuit 107 is dialed and input. If no digit is input, the CO line is blocked in step (3o). When the digit is input in the step (3l), the call time is extended by the set unit time in step (3m) and the call is returned to the step (3k) to continue the call. To make a call, repeat steps (3i) to (3n).

As described above, when the CO line connected to the DISA line is received in the private exchange system, the subscriber or the CO line subscriber can talk continuously without interrupting the call line, and the external subscriber can extend the talk time according to the situation. By providing a service, it is possible to improve a call service and to make a call convenient by allowing a password to be input only for a trunk line call.

Claims (6)

An extension call service method of a private exchange system connected to a DISA line, comprising: transmitting a dial tone to an external subscriber when a trunk line is received from an external subscriber, and transmitting the dial tone to the external subscriber in the dial tone transmission process and then calling the external subscriber. Receiving the extension number dialed from the terminal and checking the callable state of the extension subscriber; if the call is not available in the call state checking process, receiving a conversion key (*) from the external subscriber and returning to the dialtone transmission process. A process of inputting an extension number to be redialed, a process of establishing a call path in the process of checking a call availability state, switching an internal call according to a request of an external subscriber, and establishing a call path in the process of checking a call state Check the end time of the call and make an internal call as required by the external subscriber. Characterized in a constituted by any process for adjusting the cross. The method of claim 1, wherein the extension of the extension call is performed when the extension key (*) is received from an external subscriber and the extension call is transmitted by inputting another extension subscriber number. The method of claim 1, wherein the extension call adjustment process comprises: transmitting a beep to an external subscriber at the end of the extension call time; Extending the set unit time by a set unit time. In a trunk line call service method of a private exchange system connected to a DISA line, when a trunk line is received from an external subscriber, a dial tone is transmitted to an external subscriber, and after the dial tone is transmitted during the dial tone transmission, dialing is performed from an external subscriber. A process of inputting an inputted CO line access ID, a process of inputting a CO line access ID in the process of inputting a CO line access ID, transmitting a switching sound to an external subscriber, and inputting a password for a CO line call; In the process of inputting a password, connecting a CO line with an external subscriber to form a CO line call, and forming a CO line call during the CO line call formation process, dialing a different CO line number when a switch key (*) is inputted to another CO line. After the formation of a trunk line call during the process of connecting a channel and forming the trunk line call, a conversion key (*) is entered. If no way to examine the call end time, characterized in that constituted by any process for adjusting the duration of the call in accordance with an external subscriber request. The method as claimed in claim 4, wherein the process of diverting the trunk line call is to transmit the dial tone and input another extension subscriber number to switch the extension call when receiving the switch key (*) from an external subscriber. 5. The method of claim 4, wherein the CO line adjustment process comprises the steps of: transmitting an external subscriber warning tone when the internal call time ends, and transmitting a warning tone in the warning tone sending step and then setting a call time when an arbitrary digit set by an external subscriber is input. And extending the set unit time.