KR940005530B1 - Call loss prevention method - Google Patents

Abstract

The method is for supervising timer table according to incoming calls so that interprocessor communication data loss is prevented. The method comprises the steps of: (a) translating incoming phone number by a number translating block (NTR,8) in a number translating processor (NTP,5); (b) generating incoming call occupation request signal by the NTR (8); (c) sending an incoming call occupation request signal to an analog subscriber control (ASC) (10) and driving a timer; (d) processing the incoming call according to the response signal from the ASC (10) and when no response signal is detected retrying the step (c) through another unoccupied line; and (e) processing the incoming call as failure after retrying the step (c) and (d) for a certain time.

Description

How to prevent call loss when matching private exchange

1 is a block diagram of an electron exchanger subsystem to which the present invention is applied.

2 is an overall flow chart of the present invention.

3 is a flowchart of an incoming call.

4 is a flowchart of call processing after an incoming call response.

5 is a flowchart of call processing after timeout.

* Explanation of symbols for main parts of the drawings

1: Central Control Subsystem (CCS) 2: Network Subsystem (INS)

3: subscriber exchange service system (ASS) 4: maintenance processor (OMP)

5: Number Translation Processor (NTP) 6: Network Processor (INP)

7 Subscriber Switch Processor (ASP) 8: Number Translation Block (NTR)

9: Private Switching Control Block (PBXC) 10: Subscriber Call Control Block (ASC)

11: Switch Network Control Block (SNC)

The present invention relates to a method for preventing the loss of interprocessor communication (IPC) by managing a timer table for each call during an incoming process during private exchange matching in an electronic switching system.

In the past, many timers have been used in case of signal loss in call processing or other applications. However, the conventional method simply regards a failed call because a timer is put on and lost as time goes by. However, in the case of a private exchange in which multiple lines are connected to one subscriber number, there is a possibility that an empty line exists and a possible line must be connected for the service of a subscriber. Thus, the above-described conventional technique is inefficient and accurate in determining whether a call is lost. There was this.

Accordingly, the present invention has been made to solve the problems of the prior art, by applying a timetable management algorithm for managing a timer table for each call that can be applied to the exchange application program call loss that can effectively and accurately prevent call loss The purpose is to provide a method.

In order to achieve the above object, the present invention includes a central control system including a maintenance processor for adding and deleting private switching lines, changing subscriber information, outputting, and the like, and performing application and management functions of all processors. A number exchange block connected to the central control subsystem, a number translation block for number translation, a private switch control block for processing group calls, an embedded number translation processor, and a network processor for allocating and releasing a space switch channel. And a subscriber call control block connected to the network subsystem including a subscriber network and a subscriber call control block for managing a group call and managing information about subscribers. Subscriber exchange subsystems performing call processing functions It is applied to the configured electronic switch, and the number translation block in the number translation processor to perform a number translation in the case of call exchange switch call receiving the incoming call occupancy request from the number translation block, and after performing the first step After the circuit is found, a second step of making a request for occupying the incoming call with the subscriber call control block and simultaneously driving a timer, and receiving the incoming call occupancy response from the subscriber call control block after performing the second step, according to the response contents A third step of retrying the incoming call occupancy request by performing processing or finding another empty line; and if the incoming call occupancy response is not input after performing the second step and a timeout signal is transmitted, the call is repeated for a predetermined number of times. If you do not receive the incoming call occupancy response by performing the fourth step of treating as an incoming call And that is characterized.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a schematic diagram of an electronic switching system including a private exchange matching function.

In the figure, 1 is a central control subsystem (hereinafter referred to as CCS), 2 is a network subsystem (hereinafter referred to as INS), 3 is a subscriber switching subsystem (hereinafter referred to as ASS), and 4 is a maintenance processor ( (Hereinafter referred to as OMP), 5 is a number translation processor (hereinafter referred to as NTP), 6 is a network processor (hereinafter referred to as INP), 7 is a subscriber switching processor (hereinafter referred to as ASP), 8 is a number translation block ( Hereinafter, NTR), 9 denotes a private exchange control block (hereinafter referred to as PBXC), 10 denotes a subscriber call control block (hereinafter referred to as ASC), 11 denotes a switch network control block (hereinafter referred to as SNC), respectively. Indicates.

In the drawing, a plurality of connected ASSs (Access Switching Subsystems) 3 are subsystems that perform call processing functions such as subscriber and trunk line matching devices, time switches, and various signaling devices. INS (Interconnection Network Subsystem) (2) is located in the center of the system. It is a subsystem that performs the space switch function that connects the ASS (3) to each other, number translation, routing function, and group incoming function. The Central Control System (CCS) 1 is responsible for the application and management functions of all processors.

The Analog Subscriber Control (ASC) 10 mounted in the Access Switching Processor (ASP) 7 belonging to the ASS 1 manages information on the subscriber and processes the group call in association with the present block. The NTP (Number Translation Processor) 5 belonging to the INS (2) includes an NTR (Number Translation) 8 which is in charge of number translation and a Private Branch Exchange Control (PBXC) 9 which processes group calls.

In addition, the INP (Interconnection Network Processor) 6 has a Switch Network Control (SNC) 11, which is responsible for allocating and releasing a space switch channel for processing calls between ASSs 3.

OMP (Operation and Maintenance Processor) 4 belonging to the CCS (1) is responsible for the addition and deletion of private switch circuits, changing subscriber information, output.

The software for carrying out the present invention resides in the PBXC 9, which is responsible for the matching function with the private exchanger, and processes the call in association with the ASP 7.

Now, the present invention applied to the electronic switching system configured as described above will be described with reference to Figure 2 below the configuration of the process of the call loss prevention method.

2 is an overall flowchart of the present invention.

If the number is translated by NTR (8) and the private exchange is called, a call request comes to PBXC (9) (21). The PBXC 9 then finds an empty line and makes a call occupancy request to the ASC 10 (22). At the same time, the timer is operated to prepare for loss of IPC information. In other words, the incoming call information is stored in the order requested in the link-organized table for each timer identification difference. Then, the ASC 10 determines whether the call is an incoming call and notifies the request (23).

When the IPC information is lost, the timer times out and the time out signal is transmitted (24). The timer occupies a request for the occupancy of the timer table based on the information on the called subscriber in the signal (25). If the incoming response is received (26), the same procedure is performed. If the incoming occupancy response is not received until the timeout is three times, then the incoming response is treated as impossible.

3 is a flowchart of an incoming call.

When the call is received on the private switch line, the terminal receives an incoming request from the NTR 8 (31), and then finds group information about the incoming line (32). It searches for a free line in the group (33), and asks whether it is a ringable line to the called subscriber processor, sends it to the subscriber processor, receives a response, and processes it. Then, after the incoming call request is sent to the ASC 10 (34), the timer is set to store information per line in the timer table (35), and the call occupancy wait state is reached (36).

Signals that can be received in the incoming call waiting state can be divided into incoming occupancy response and time-out. If the incoming call is received, normal processing is performed as shown in FIG. 4, and in case of time-out processing, Do the same.

4 is a flowchart of call latch after incoming call response.

In the incoming call waiting state, the mobile station receives the incoming call response from the subscriber processor through the normal path (41). At this time, the set timer is canceled and the related information is canceled (42). The answer result is determined whether the answer is possible or impossible (43). If the answer result is possible, the incoming call is occupied and the state of the line is in use (44). , 45). If the call cannot be received, the next empty line is searched for (46), and the process proceeds to step 34 for requesting the incoming call of FIG.

5 is a flowchart of call processing after timeout, which is a process after receiving a timeout message.

The time out signal is received after a predetermined time from the operating system (OS) (51). After the timer table is found (52) with the information of the line that has timed out, it is determined whether the time-out is three times or less for the incoming line. If the determination result is 3 or less, the next empty line is found (54) and the incoming call occupancy request is requested. The processing after the incoming request is the same as that in Fig. 3, and if the incoming call response does not come until the timeout is three times, the line is considered to be in use or the incoming call is processed and the number translating block (NTR) 8 is processed. Notify and process as a failure call (55).

The present invention carried out by the above processing procedure is useful for preventing call loss of a private exchange where a plurality of lines are connected with one representative number and an empty line may exist even if one line is in use, especially in case of a group call, The effect of preventing loss of fire is great.

Claims (5)

The Central Control Subsystem (CCS) (1), which includes the Maintenance Processor (OMP) 4 responsible for adding and deleting private exchange lines, changing subscriber information, printing, etc., and is responsible for the application and management functions of all processors. A number translation block (NTR) 8 which is connected to the central control subsystem (CCS) 1 and is responsible for number translation, and a private exchange control block (PBXC) 9 for processing group calls. A network subsystem (INS) 2 comprising a number translation processor (NTP) 5 and a network processor (INP) 6 which is responsible for allocating and releasing space switch channels; And a subscriber call control block (ASC) 10, which is connected to a number of (INS) (2) and manages information on subscribers and processes group calls, and includes subscriber and relay line matching devices, time switches, and various signaling devices. Subscriber to perform call processing function A method for preventing call loss when matching a private exchange of an electronic switching system comprising an exchange subsystem (ASS) 3, wherein the number translation block (NTR) 8 in the number translation processor 5 performs number translation. In the case of a call, a first step 21 receiving an incoming call request from the number translation block (NTR) 8 and an empty line after performing the first step 21 are performed and the subscriber call control block (ASC) ( 10) receiving the incoming call occupancy response from the second call 22 and the subscriber call control block (ASC) 10 after the second step 22 is performed. A third step (23) for performing call processing or retrying an incoming call occupancy request by searching for another empty line according to the contents of the response; and after performing the second step (22), the incoming call occupancy response is not input and the timeout signal is not inputted. Is sent, repeat the incoming request for a certain number of times Thus, if the incoming call occupancy response is not received continuously, the call loss prevention method, characterized in that performed by the fourth step (24 to 27) to treat as an incoming call. 2. The method of claim 1, wherein the second step (22) comprises: (31,32) searching for incoming subscriber information after receiving an incoming call occupancy request; and (33) finding an empty line in a group line to which the called subscriber belongs. And requesting the incoming call occupancy to the subscriber call control block (ASC) 10 and storing the information on the occupied request line for each timer identifier to create a table (34, 35). And sending (36) whether or not it is possible to the subscriber processor and going to an incoming call occupancy waiting state (36). The method of claim 1, wherein the third step (22) comprises the steps (41, 42) of clearing the timer for the requested line and removing the related information when the incoming occupancy response is received in the incoming occupancy waiting state; If the result of the on-response is available, the incoming call is seized and goes to the busy busy state (43 to 45); if the answer from the subscriber processor is not possible, the next free line belonging to the group is found and the incoming call is seized again. A method for preventing call loss, characterized in that it is performed by steps (43, 46) of making a request and going to an incoming call occupancy state. 4. The method of claim 1, wherein the fourth steps (24 to 27) include searching for information of the timed out line (51, 52) when a timeout signal is input, and the number of timed out for the requested call is constant. (53) checking whether the number is more than the number of times, and if the number of times is less than the predetermined number of steps, requesting the incoming call to be occupied again (54); And (55) informing the number translation block (NTR) of the call loss prevention method. The method of claim 4, wherein the predetermined number of times is three.