JPH06350684A - Private branch exchange and common carrier selecting method - Google Patents

Abstract

PURPOSE:To provide a private branch exchange and the common carrier selecting method which equally select plural common carriers to connect a destination and a line so that only a specific common carrier is not used for originating call trunk line. CONSTITUTION:When receiving the telephone number for originating call trunk line from, for example, a multifunction telephone set 2 through a digital telephone interface circuit 12, a CPU 15 selects a carrier to be used from plural carriers, which can be used for each ground number of the telephone number by the round robin method, and sends a dial signal corresponding to the processed telephone number onto a subscriber line network 4 from a trunk line trunk interface circuit 14 after processing the telephone number so that this selected carrier can be used. Thus, common carriers are equally used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a private branch exchange, and more particularly to a method of selecting a common carrier (sometimes simply referred to as a carrier) used when transmitting a local line.

[0002]

2. Description of the Related Art When an extension terminal originates an office line through a private branch exchange, the caller is conscious of only a number other than an area code and dials, and which common carrier is used to make the call. It is common not to. In recent years, not only an NTT line but also a line provided by a so-called NCC (New Common Carrier) exists, so that it has become possible to select an arbitrary common carrier and connect the line to a partner. Therefore, in the case of transmitting a station line through a private branch exchange as described above, a system that uses only the NTT line as shown in FIG. 6 or a system that fixedly allocates carriers to each ground as shown in FIG. is there. In such a system, a carrier that is a candidate for each ground is stored as data inside the private branch exchange, and the data with the cheapest call charge per unit time is preset so that the extension LCR (Least Cost Routing) that automatically selects the cheapest carrier when calling
Systems exist. In addition, as shown in FIG. 8, the private branch exchange 1 sends the caller's dial as it is to the built-in station line interface, and sends it out so that the cheapest carrier is selected before going out to the subscriber network 4. External L
There is a system or the like that is processed by the CR device 5.

FIG. 6 shows an example of a system using only the above-mentioned NTT line. The private branch exchange 1 sends the dial signal from the telephone 3 of the terminal to the subscriber line network 4 as it is. FIG. 7 is a diagram showing an example of a system in which carriers are fixedly assigned for each ground described above, and the private branch exchange 1 is one of the carriers fixedly assigned to the ground number of the telephone number input from the telephone 3 of the terminal. Number, 00 in this example
88 is read from the table 50, and this 008 is added to the head of the telephone number input from the telephone 3 and transmitted to the subscriber line network 4. FIG. 8 is a diagram showing an example of a system in which the above LCR device 5 is externally attached. The private branch exchange 1 uses the telephone number entered from the terminal telephone 3 as it is
R device 5 The LCR device 5 selects the carrier with the lowest line charge, processes the telephone number so that the carrier can be used, and sends it to the subscriber line network 4.

By the way, in the case of a company that adopts a strategy of making a plurality of common carriers generate a certain profit without being biased to a certain common carrier with respect to the use of a line, the conventional private branch exchanges uniformly distribute the plurality of common carriers. There is a defect that there is no function to make local line transmission while selecting, and it is not possible to deal with the above corporate strategy.

[0005]

Conventionally, when an extension terminal originates an office line through a private branch exchange, common carriers to be used are uniformly selected without being biased to a specific carrier, and a line is connected to a destination. There is no one that has the function to do so, and there is a drawback that it is not possible to respond to the request that a plurality of common carriers uniformly raise a certain amount of profit.

In view of the above, the present invention eliminates the above-mentioned drawbacks, and evenly distributes the carriers used among a plurality of common carriers so that the common carriers used when transmitting a local line are not biased to a specific carrier. An object of the present invention is to provide a private branch exchange and a common carrier selection method capable of selecting and connecting a destination and a line.

[0007]

According to the present invention, any one common carrier can be selected from a plurality of common carriers that can be used when an extension terminal originates an office line, and the selected common carrier can be used. In the private branch exchange that processes the telephone number input from the extension terminal as described above and makes a call to the subscriber line network, a storage means for setting a plurality of common carriers that can be used for each ground and a local line transmission this time Searching means for searching for a plurality of available common carriers set in the storage means from the ground number of the destination of, and a common carrier used for the present station line transmission from the plurality of common carriers searched by this searching means Is selected in order so that the usage rate of each common carrier becomes equal, and the common carrier selected by this selection means is used. Having the configuration and a calling means for calling.

[0008]

In the private branch exchange of the present invention, the storage means sets a plurality of common carriers available for each ground. The search means searches a plurality of available common carriers set in the storage means from the ground number of the destination of the current station line transmission. The selecting means sequentially selects, from the plurality of common carriers searched by the searching means, the common carriers to be used for the local station transmission this time so that the usage rates of the common carriers are equal. The calling means uses the common carrier selected by the selecting means to make a call.
As a result, it is possible to equalize the usage rates of a plurality of common carriers and make each common carrier generate a certain amount of profit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a private branch exchange of the present invention. 1 is a private branch exchange, 2 is a multi-function telephone which is an extension terminal, 3 is a standard telephone which is an extension terminal, and 4 is a subscriber line network. The private branch exchange 1 includes a switch circuit 11 for connecting / disconnecting extension lines and / or extension lines and office lines, a digital telephone interface circuit (DSTI) 12, a standard telephone interface circuit (BSTI) 13, a central line trunk interface circuit (COTI) 14, and a private branch exchange. It has a CPU 15 that performs exchange control and various service controls, and a memory 16 that stores various programs and data necessary for the CPU 15 to operate. A busy tone generator 20 is provided in the switch circuit 11.

FIG. 2 is a diagram showing an example of an index data table stored in the memory 16 shown in FIG. The index numbers of the carrier data table to be referred to for each ground number are listed.

FIG. 3 is a diagram showing an example of the contents of the carrier data table described above. These carrier data tables are stored in the memory 16 shown in FIG. Each table lists a plurality of carriers that can be used and a trunk group number to which each carrier is assigned. Areas (a) to (c) storing the index number indicating the carrier to be selected next and the number of usable carriers (the number of members) are stored in the memory 16 for each carrier table.

Next, the operation of this embodiment will be described. For example, when the caller dials the destination telephone number to make a station call from the multifunction telephone 2, the CPU 1 of the private branch exchange 1
5 is the digital telephone interface circuit 1 for the telephone number
After being input via 2, the common carrier selection operation described below is performed, and then a dial signal is transmitted from the office line trunk interface circuit 14 to the subscriber line network 4.

FIG. 4 shows the CPU 1 in the private branch exchange 1 described above.
6 is a flowchart showing a common carrier selection operation according to No. 5. First, in step 401, the CPU 15 inputs the telephone number from the extension terminal to the digital telephone interface circuit 1
2 or the standard telephone interface circuit 13, the index number of the carrier data table to be referred to from the index data table shown in FIG. Ask for. Next, the CPU 15 operates the memory 16 shown in FIG.
In the carrier data table as shown in step 403
To access. Where the index number is 1
If so, the carrier data table to be referred to is shown in FIG.
The table shown in (A) is obtained, but the CPU 15 reads out the index number of the next index table shown in (a) which is set corresponding to this, and identifies the carrier indicated by this index number and the trunk group assigned to it. read out. In this example, the index number indicating the carrier used this time is 1, so CP
U15 reads 008 as a carrier to be used from the first column of the carrier data table of FIG.
Read out.

Next, the CPU 15 proceeds to step 404 to determine whether or not there is a vacancy in the trunk group 10, and if so, proceeds to step 407 and sets the telephone number in which 008 is added to the head of the input telephone number. make,
Dial the signal corresponding to this number to trunk group 1
The call is sent from 0 to the subscriber line network 4. Then C
In step 408, the PU 15 increments the index number of the next index table of FIG. 3A by 1, and ends the process. On the other hand, step 40
If there is no vacancy in trunk group 10 at 4, C
The PU 15 proceeds to step 405, and determines the number of members set in the next index table of FIG.
In this example, it is determined whether or not the table search has been performed for all the members 5, and if not, step 40
6, the index number shown in FIG. 3A is incremented by 1, and the process returns to step 403. On the other hand, when the table is searched by the number of members in step 405, the process proceeds to step 409, the CPU 15 connects the digital telephone interface circuit 12 to the busy tone generator 20, and then the process ends. However, in the increment of the index number, when the index number reaches the number of members, it is returned to 1 and incremented by 1 again.

Here, the operation of the CPU 15 will be described more specifically. For example, when there is a station line call to the ground number 011, the carrier used is 00 in FIG. 3 (A).
If 88 is selected, then 0070 is selected as the carrier to be used when there is a station line transmission with the ground number 011.
In the same manner thereafter, eventually, the carriers to be used are sequentially selected with the number of members in the table shown in FIG. However, at this time, if there is no vacancy in the trunk group assigned to each carrier, the next carrier is selected, and in this case, carrier selection is completed in a maximum of one round with the number of members as the upper limit, and eventually, If there is no space in the trunk group, it becomes busy. Such a carrier selecting operation is the same for the carrier data tables shown in FIGS. 3B and 3C.

According to this embodiment, a plurality of carriers that can be used for each ground are set as shown in FIG. 3, and after using one carrier, the next carrier is used in order. Since the selection is made, it is possible to make the carriers used for each ground even when transmitting a local line from an extension, and to make a plurality of common carriers generate a certain profit without being biased to one common carrier. You can Also, when multiple carriers are searched in such a round robin format and the trunk group that can use that carrier happens to be on the phone, the next carrier is selected. It is possible to reduce the probability that the group is busy during all the calls and to perform smooth local transmission from the extension.

FIG. 5 is a flow chart showing another embodiment of the present invention. In this example, the carrier selection at the time of station line transmission is as follows: If the carrier selected in the round robin format has no available trunk group, the next carrier is not selected and The control is done. Therefore, after selecting a carrier and a trunk group from the carrier data table shown in FIG. 3 in step 503, the next index is advanced by 1 in step 504, and then step 505.
At step 506, it is determined whether or not there is a vacancy in the selected trunk group. If yes, a call is made at step 506, but if not, a busy tone is sent to the extension terminal at step 507. Note that the processing of steps 501 and 502 is the same as in the case of FIG. 4, and in this example as well, the carriers used for each ground can be made uniform when transmitting a station line from an extension line, and are biased to one common carrier. Instead, multiple common carriers can generate a certain amount of profit.

[0018]

As described above, according to the private branch exchange and the common carrier selection method of the present invention, a plurality of common carriers are used so that the common carrier used when transmitting a station line is not biased to a specific carrier. It is possible to evenly select carriers to be used in the above and connect the destination and the line.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a private branch exchange of the present invention.

2 is a diagram showing an example of an index data table stored in a memory shown in FIG.

FIG. 3 is a diagram showing an example of a carrier data table stored in a memory shown in FIG.

4 is a flowchart showing a carrier selecting operation by a CPU in the private branch exchange 1 shown in FIG.

FIG. 5 is a flowchart showing another embodiment of the present invention.

FIG. 6 is a diagram showing an example of a system using only a conventional NTT line.

FIG. 7 is a diagram showing an example of a conventional system in which carriers are fixedly assigned for each ground.

FIG. 8 is a diagram showing an example of a system in which a conventional LCR device is externally attached.

[Explanation of symbols]

1 ... Private branch exchange 2 ... Multi-function telephone 3 ... Standard telephone 4 ... Subscriber line network 11 ... Switch circuit 12 ... Digital telephone interface circuit 13 ... Standard telephone interface circuit 14 ... Station line trunk interface circuit 15 ... CPU 16 ... Memory 20 ... Busy tone generator

Claims (3)

[Claims] 1. An extension terminal selects any one of a plurality of common carriers that can be used when an extension terminal makes an office call, and inputs from the extension terminal so that the selected common carrier can be used. In the private branch exchange that processes the specified telephone number and makes a call to the subscriber line network, the storage means for setting a plurality of common carriers that can be used for each ground and the ground number of the destination of the present station line transmission A search means for searching a plurality of available common carriers set in the storage means, and a usage rate of each common carrier for the common carrier used for the present station line transmission from the plurality of common carriers searched by this search means. And a calling means for calling using the common carrier selected by the selecting means. A private branch exchange characterized by being equipped. 2. When all the line trunks assigned to the common carrier selected by the selecting means are busy,
2. The private branch exchange according to claim 1, wherein another common carrier is sequentially searched by the maximum set number of common carriers until a common carrier capable of capturing an office line trunk having an idle line is found. 3. An extension terminal selects any one common carrier from a plurality of available common carriers when the extension terminal makes an office line transmission, and inputs from the extension terminal so that the selected common carrier can be used. In the private branch exchange that processes the specified telephone number and makes a call to the office line, the common carrier to be used for each call to the office line is selected in order so that the plurality of common carriers are equally used. Common carrier selection method.