JPH0993626A - Path selection method for exchange - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a path selection method in which path selection processing is conducted at a high speed and a storage capacity required for path connection information is reduced. SOLUTION: A selection number informed from a caller side is divided into a number string in a prescribed digit number by a division means 12 of a processor 11, a set composed of plural numerals by numeralizing the number string with a numeralizing means 13. Similarly plural path selection numbers denoting a trunk path contained in an exchange 1 is numeralized and the result is registered in a memory 16 as path selection information 17 and a selection means 14 retrieves path selection information 17 based on the set representing the selection number informed from the caller and a connection destination path is selected in response to the result of retrieval.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exchange and a connection route selection method therefor, and more particularly to a switching network connection method for selecting a route corresponding to the exchange based on a received selection signal.

[0002]

2. Description of the Related Art In general, a switching network, as shown in FIG.
It is composed of a plurality of exchanges 51 connected to each other by a trunk path 53, and subscriber terminal equipment 52 such as telephones accommodated under the exchange 51 via a subscriber line 54. At each exchange 51, the calling subscriber's terminal equipment 5
A call relay process for connecting a line from 2 to the subscriber terminal equipment 52 on the called side is executed. When the line connection request is actually received from the calling side exchange or the subscriber terminal equipment, the exchange 51 is connected to its own station based on the selection signal received from the calling side together with the line connection request. Any one of the plurality of trunk routes 53 is selected.

A unique route selection number is given to each trunk route 53 connected to the exchange 51, and the correspondence relationship between them is registered in advance in the exchange 51 as route selection information as shown in FIG. Has been done. Here, each trunk route 53 is managed by a unique connection trunk number 62, and the connection trunk number 62 and the selected route number 61 consisting of character information are registered in association with each other.

Therefore, the exchange 51 derives a selection number consisting of character information of a predetermined number of digits from the received selection signal, compares it with each route selection information, and selects the corresponding trunk route 53 according to the comparison result. Will be things. Conventionally, in the process of selecting a connection destination route using such route selection information, the selection number notified from the calling side and the plurality of route selection numbers 61 registered as the route selection information each have one digit. (1 character) is sequentially compared to detect a match or a partial match, and the detected route selection number 61
The connection destination route is selected based on the connection trunk number 62 corresponding to.

[0005]

Therefore, in such a conventional connection route selection method, the selection number notified from the calling side and the plurality of route selection numbers registered as the route selection information are digitized by one digit. Since the comparison is performed one by one (one character), it takes a long time from receiving the selection signal from the calling side to selecting and connecting a predetermined route,
In particular, when the number of digits of the selection number increases or the number of connection destination trunk routes 53 increases, there is a problem that it becomes more remarkable. For example, if 7 digits are required for the selection number to select the trunk route 53, 7
It is necessary to sequentially compare the digit characters for digits, and when 10 trunk routes are registered as the route selection information, it is necessary to compare the numeric characters for a maximum of 7 × 10 times.

Further, when the route selection information registered in advance in the exchange 51 increases, the storage medium required for this also increases. As the route selection information, the memory built in the call control unit in the exchange is used. However, when each digit of the route selection number is registered as a character as the route connection information as shown in FIG. Generally, since 2 bytes of storage capacity are required for each character, the required storage capacity increases corresponding to one connection trunk number, and if the number of trunk routes is large, the available storage capacity increases. Since there is a limit, there is a problem that it is not possible to register all route selection information. The present invention is intended to solve such a problem, and provides a switch and a route selection method thereof capable of performing a route selection process at high speed and reducing a storage capacity required for route connection information. Has an aim.

[0007]

In order to achieve such an object, the route selection method for an exchange according to the present invention is provided with a digitizing means for converting a predetermined number sequence into a numeric value, and the digitizing means is used. , The route selection number unique to each trunk route is converted into a numerical value and registered in advance in the storage means as route selection information, and when the selection number is notified from the calling side, this selection number is converted by the digitizing means. Converted to the first numerical value, the second numerical value indicating the route selection number is sequentially read from the route selection information registered in the storage means, the first numerical value and the second numerical value are compared, and the comparison result The trunk route corresponding to the route selection number is selected as the connection destination route according to the above. Therefore, the selection number notified from the calling side is converted into the first numerical value by the digitizing means, and the second numerical value indicating the route selection number is sequentially read from the route selection information registered in the storage means. hand,
The first numerical value and the second numerical value are compared, and the trunk route corresponding to the route selection number is selected as the connection destination route according to the comparison result.

Further, there are provided dividing means for dividing the predetermined number sequence into a plurality of number sequences having a predetermined number of digits, and numerical conversion means for converting each number sequence generated by the dividing means into a numerical value. By dividing means and digitizing means,
The route selection number unique to each trunk route is divided and converted into a group consisting of a plurality of numerical values, which is registered in advance in the storage means as route selection information. When the calling side notifies the selection number, the dividing means is divided. And the digitizing means divides the selection number to convert it into a first set consisting of a plurality of numerical values, and from the route selection information registered in the storing means, a second set consisting of a plurality of numerical values indicating the route selection number. The selection numbers shown in the first set and the route selection numbers shown in the second set are compared by sequentially reading and comparing the numerical values forming the first and second sets individually, and the comparison result The trunk route corresponding to the route selection number is selected as the connection destination route according to the above. Therefore, the selection number notified from the calling side is divided by the dividing means and the digitizing means to be converted into the first set consisting of a plurality of numerical values, and the route selection is made from the route selection information registered in the storage means. A second set consisting of a plurality of numerical values indicating numbers is sequentially read out, and the numerical values forming the first and second sets are individually compared to select the selection number and the second number shown in the first set. The route selection numbers shown in the group are compared, and the trunk route corresponding to the route selection number is selected as the connection destination route according to the comparison result.

Further, the digit number of the third numerical value indicating all or part of the selection number notified from the calling side is changed to the fourth number indicating all or part of the route selection number registered as the route selection information. In the case of providing a digit aligning means for aligning with the number of digits of the third numerical value and comparing the third numerical value with the fourth numerical value, the digit aligning means changes the number of digits of the third numerical value into the digit of the fourth numerical value. After the numbers are set, the two are compared. Therefore, the third numerical value indicating all or part of the selection number notified from the calling side and the fourth numerical value indicating all or part of the route selection number registered as the route selection information.
When compared with the numerical value of
After the number of digits of the third numerical value is aligned with the number of digits of the fourth numerical value, the two are compared.

[0010]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an exchange which is an embodiment of the present invention. In FIG.
Is a trunk having an outgoing register 3 and an incoming register 4 to accommodate a trunk route 5, 6 is a trunk having an outgoing register 7 and an incoming register 8 to accommodate a trunk route 9, and 10 is various call control including route selection information 17. A call processing control unit 19 having a memory 16 for storing information and a processor 11 for executing various call processes including a route selection process, and 19 sends various call control information including route selection information 17 to the call processing control unit 10. It is a maintenance terminal to be registered.

In the processor 11, 12 is a dividing means for dividing the selected number into a number string having a predetermined number of digits, 13 is a numerical value converting means for digitizing the number string generated by the dividing means 12, and 14 is from the calling side. Selection means for comparing and searching the route selection information 17 based on the selection numbers divided and digitized by the dividing means 12 and the digitizing means 13 to select a predetermined connection destination route, 15 is a numerical value to be compared and searched. This is a means for aligning digits.

Next, the operation of the present invention will be described with reference to FIG. When a call connection request is made in the calling exchange or the subscriber terminal equipment, a predetermined selection signal is transmitted to the exchange 1 via the trunk route 5. This selection signal is received by the incoming call register 4 of the trunk 2 and converted into a selective number consisting of character information in the incoming call register 4,
The call processing control unit 10 is notified.

In response to this, the processor 11 of the call processing control unit 10 controls the dividing means 12 and the digitizing means 13 to convert the notified selection number into several sets of numerical values,
The selection unit 14 searches the memory 16 for the route selection information 17 consisting of route selection numbers registered in advance in the memory 16 as a similar set of numerical values, and determines whether the two sets match or mismatch.
When the result of this determination indicates a match, the connection trunk number corresponding to the notified selection number is acquired from the route selection information 17, and the trunk 6 corresponding to the connection trunk number is acquired.
Is selected and the transmission register 7 is controlled to connect the trunk route 5 and the trunk route 9.

Next, with reference to FIG. 2, the dividing means 12 and the digitizing means 13 for converting the selection number notified from the calling side or the route selection number inputted from the maintenance terminal 19 into several sets of numerical values. The operation of will be described. The selection number input to the call processing control unit 10 from the calling side or the maintenance terminal 19 is notified to the processor 11 as a character string 20.
In response to this, the processor 11 controls the dividing means 12 to divide the character string 20 into a predetermined number of digits, and generate number strings 21 to 23 including character information.

In this case, the number of digits as the division unit is based on the maximum integer type that the processor 11 can calculate as an integer value. For example, if the maximum integer type that can be handled by the arithmetic processing of the processor 11 is 2 bytes, "0
~ 65535 (= 2 ¹⁶ ) "(uns defined in C language
Igned short type equivalent), also s in the signed defined by "32767 (= 2 ^15)" (C Language
It is possible to perform integer arithmetic processing (equivalent to the hort type).

In practice, since "0 to 9" are arbitrarily used as selection numbers, when these selection numbers are regarded as integers and numerically expressed, they are substantially "0 to 9999".
An integer of digits can be handled, and the number of digits that is a division unit in this case is 4. Therefore, a 10-digit character string 2
0 "0123456789" is divided into four digits from the beginning, and a four-digit number string 21 "0123" and a number string 2
2 "4567" and the remaining two-digit number sequence 23 "89" are generated.

If the maximum integer type that can be handled by the arithmetic processing of the processor 11 is 4 bytes, "0 to 429496795 (= 2 ³² )" (unsigned long type defined in C language) is used without a code. Equivalent), or with a sign, it is possible to perform integer arithmetic processing of “0 to 214748367 (= 2 ³¹ )” (equivalent to the long type defined in the C language), and substantially 9 of “0 to 999999999” is possible. You will be able to handle digit integers. Therefore, in this case, the 10-digit character string 20 "0123456789" is
9-digit number string "01234"
5678 "and the remaining one digit number string" 9 "are generated.

Further, such division processing of the selection number is
This is an indispensable process when the number of digits of the numerical value that can be processed by the processor 11 is limited.
When the selection number can be handled without any problem by the largest integer type that can be arithmetically processed in 1, it is not necessary to provide such a dividing means 12 to perform the dividing process. For example, when the maximum integer type that can be processed by the processor 11 is 4 bytes and the maximum number of digits of the selection number that should be converted into a numerical value is 7 digits, an integer value of 7 digits is set as described above. It can be handled as a 4-byte integer type by the processor 11 without any problem, and division processing is not required.

In this manner, the input selection number is divided into a number string having a predetermined number of digits that can be arithmetically processed by the processor 11, and then the digitizing means 13 digitizes these number strings. Note that digitization means, for example, "1", "
The number string input by various character string data "2" is changed to "1.
2 shows a process of converting into numerical data "2". First, in each number string, if the number of the first digit is not "0" or if the number of digits of the number string is less than the number of digits of the division standard, read the integer value as it is and the integer value It should be the value shown. In the above-mentioned FIG.
23 is the target, and "4567" is "45".
It is converted to the integer value 26 of "67" and "8"
9 ″ is converted to the integer value 27 of “89”.

On the other hand, the first digit of the number string to be converted into a numerical value is "
If it is 0, the first digit "0" disappears if it is read as an integer, so the character "1" is added to the digit one digit higher (on the left) than the first digit of the number string.
Further, a negative sign "-" is added and read again as an integer value. As described above, the number of digits used as the division standard of the number string is determined by the maximum integer type that can be processed by the processor 11, and the highest digit of the maximum number that can be processed by this integer type is "0-". Since not all "9" can be handled, division processing is performed with a digit number that is one digit less than this digit number.

Therefore, paying attention to the fact that the highest digit represented by the integer type that is the division criterion is not used in the arithmetic processing, and using this digit, the number string whose leading digit is "0" To quantify. Also, simply the character "1"
If you add and re-read as an integer, the value will be the same as if you read the number string with the most significant digit "1" as an integer. The code is added.

For example, when the maximum integer type that can be processed by the processor 11 is 2 bytes, the maximum number that can be handled is 5 digits of "0 to 65535" as described above, but the most significant digit thereof. Since only "0-6" appears, it is actually divided into a 4-digit number string. However, paying attention to the fact that if the numerical value handled as the most significant digit is limited to "0 to 6", the numerical value of 5 digits can be handled, and the character "1" is designated as the most significant digit.
The number sequence starting with "0" is digitized by adding a minus sign.

Therefore, in FIG. 2, the number sequence 21 "0
When 123 ”is read as an integer value as it is, it becomes the numerical value“ 123 ”, which is the number string without“ 0 ”at the beginning.
Although it becomes the same value as 123 ", according to the above method, the number sequence 21" 0123 "becomes the number sequence" -10123 ".
After being converted into, the numerical value is converted into the numerical value 25 of "-10123", and both are distinguished. As another example, the number string "0"
045 ″ is converted into a numerical value of “−10045”.

Also, in the case where the leading digit is "0" in the number string which does not reach the number of digits of the division unit, "1" is added as the most significant digit and the minus sign is added in the same manner as described above. Reread as an integer. Therefore, for example, if the maximum integer type that can be processed by the processor 11 is 2 bytes, the number string with the number of digits less than 4 digits in the division unit "
092 "is converted to" -1092 "and then" -10 "
It is converted into the numerical value of "92".

In this way, the calling side or maintenance terminal 1
9, the selection number 20 "012345 as shown in FIG.
When 6789 "is input, the digitization processing as described above is performed, and the numeric value 25" -10123 ", the numeric value 26
It is converted into a set of three numerical values “4567” and a numerical value 27 “89”.

A set of these numerical values is registered as the route selection information 17 in the memory 16 as shown in FIG. In the figure, 31 is a plurality of numerical values indicating a route selection number, 32
Is the connection trunk number of the route corresponding to this. It is necessary to secure in advance a memory area required for storing each route selection information 17 in the memory 16, and its capacity is the number of bytes of the integer type used as a reference in the above-mentioned digitization process. And depends on the number of divisions.

For example, 7 is selected as a selection number for selecting a route.
The largest integer type that requires a digit number and that can be processed by the processor 11 is 2 bytes (division unit 4 digits)
, The number of divisions of the number sequence is two, as described above. Therefore, it is only necessary to declare a 2-byte signed integer array having two array elements for each piece of route selection information.

Next, with reference to FIG. 4, the operation of the selecting means 14 for searching the route selection information based on the selection number notified from the calling side and selecting a predetermined connection destination route will be described. FIG. 4 is an explanatory diagram showing the operation of the selecting means. First,
The selection number notified from the calling side exchange or the subscriber terminal equipment by the selection signal is converted into a plurality of numerical value groups (first group: hereinafter referred to as group A) by the dividing means 12 and the digitizing means 13. To be done.

Next, from the route selection information 17 in the memory 16, a set of numerical values indicating the route selection number corresponding to each route (second set: hereinafter referred to as set B) is read in order,
Compared to set A. In this case, the respective numerical values constituting both sets are individually compared. For example, if the maximum integer type that can be processed by the processor 11 is 2 bytes,
As shown in FIG. 4, the selection number 4 notified from the calling side
1 "0123456" is divided into four digits and the numerical value A
It is digitized into 1 "-10123" and the numerical value A2 "456".

On the other hand, as the route selection information 17 from the memory 16, the numerical value B1 indicating the route selection number "012345".
When "-10123" and the numerical value B2 "45" are read out, the numerical values A1 and B1 and the numerical values A2 and B that form these pairs are read.
2 are compared individually. In this case, the exclusive OR of both numerical values is calculated, and when the result is "1", it is determined that both numerical values match.

Therefore, the numerical value A1 "-10123" and the numerical value B1 "-10123" match, but the numerical value A2
Since "456" and the numerical value B2 "45" do not match, it is determined that the A set and the B set do not match, and the selection number 41 input from the calling side and the route selection information 17 of the memory 16 are set to B. It is different from the route selection number read out as a set, and it is determined that the route corresponding to this route selection number is not the desired connection destination route.

In the actual route selection processing of the exchange, even if the digit number of the selection number notified from the calling side is larger than the digit number of the route selection number registered as the route selection information, the route selection is performed. If all numbers in the numbers are compared from the beginning of the selection number and match, the number may be selected as the connection destination. For example, in FIG. 4 described above, the selection number 41 ″
0123456 "and route selection number 42" 012345 "
When comparing, all the digits of the route selection number 42 partially match from the beginning of the selection number 41.

When detecting such partial coincidence, when comparing the numerical values of the respective sets, first, the numbers of digits of both numerical values are compared, and if the numbers of digits match, as described above, the two numbers are compared. The exclusive OR (EX-OR) is calculated, and the match / mismatch is determined according to the result. If the number of digits is different, the digit aligning means 15 causes the numerical value on the side of the selection number having a large number of digits, that is, the A group side (third numerical value), to the numerical value on the side of the route selection number having a small digit number, that is, the numerical value of the B group side. After aligning with the (fourth numerical value), an exclusive OR (EX-OR) of both is calculated, and a match / mismatch is determined according to the result.

As for the method of aligning the number of digits, for example,
Numerical value A2 is the same as numerical value B2.
If the value is 3, the numerical value A3 is obtained based on the following arithmetic expression. ^{A3 = int (A2 / 10 n} ) n = int (log 10 (A2)) - int (log 10
(B2)) Here, int (X) indicates an int function that rounds down the decimal point of the numerical value X and returns only an integer value.

In the above equation, n is a numerical value A2 and B.
The difference in the number of digits from 2 is shown. The numerical value A2 is divided by "10" by the difference in the number of digits, and then only the integer part is extracted by the int function. The numerical value A3 and the numerical value B2 thus obtained are compared, and in the case of FIG. 4, both are “45”, which coincides with each other. Therefore, from the route selection information 17 corresponding to this B group, the connection destination trunk number To get
The trunk 6 (see FIG. 1) corresponding to the connection trunk number is selected, and the transmission register 7 is controlled to connect the trunk route 5 and the trunk route 9.

As described above, the processor 11 of the call processing controller 10 is provided with the digitizing means 13 and the selecting means 14 to convert the selection number notified from the calling side into a numerical value (first numerical value). In the same manner, the route selection information 17 in which the numerical value (second numerical value) indicating the route selection number is registered in advance is searched, and the connection destination route is selected according to the search result. In addition, the number of comparisons is significantly reduced compared to the case of sequentially comparing the characters that make up the selection number and the route selection number one digit at a time, from the reception of the selection signal from the calling side to the selection and connection of a predetermined route. It is possible to shorten the time required for the processing, and particularly when the number of digits of the selection number is increased or the number of connection destination trunk routes is increased, the processing time is more significantly shortened.

Further, after converting the route selection number forming the route selection information 17 into a numerical value by the digitizing means 13,
Since it is registered in the memory 16, it is possible to reduce the required storage capacity corresponding to one connection trunk number, as compared to the case of registering as character information as in the conventional case, and more trunks can be stored. The route selection information 17 corresponding to the route can be registered, and the memory 16 in the call processing control unit 10 can be effectively used.

Further, a dividing means 12 is provided in the processor 11 to divide the inputted selection number into a number string having a digit number which can be processed by the maximum integer type which can be processed by the processor 11, and then the digitizing means 13 is provided. Therefore, even if the number of digits of the numerical value that can be processed by the processor 11 is smaller than the maximum number of digits of the selection number, it can be handled without any problem.

Further, if the digit aligning means 15 is provided in the processor 11 and the digit number of the selection number notified from the calling side is larger than the digit number of the route selection number, Since the digit aligning means 15 aligns the number of digits of the numerical value indicating the selection number with the number of digits of the numerical value indicating the route selection number, the two are compared, so that a plurality of selection numbers having the same several digits from the beginning are arranged. Even when one route selection number is associated as the common connection destination corresponding to, it is possible to accurately select the connection destination route.

[0040]

As described above, according to the present invention, the digitizing means for converting a predetermined number sequence into a numerical value is provided, and by this digitizing means, the route selection number is converted into a numerical value and registered in advance. Then, the selection number notified from the calling side is converted into the first numerical value by the digitizing means, and the second numerical value indicating the route selection number is sequentially read out to obtain the first numerical value and the second numerical value. Since the comparison is made and the connection destination route is selected according to the comparison result, the number of comparisons is significantly larger than in the conventional case where the characters constituting the selection number and the route selection number are sequentially compared one digit at a time. It is possible to shorten the time required from selecting a predetermined route to receiving a selection signal from the calling side and connecting to it. In particular, the number of digits in the selection number is increased or the connection trunk route is connected. Is more pronounced when Processing time is shortened to. further,
Since the route selection number that composes the route selection information is converted into a numeric value and registered, 2 characters per character as in the past.
Compared with the case of registering as character information requiring bytes, it is possible to reduce the storage capacity required for one connection trunk number, and register route selection information corresponding to more trunk routes. The storage means can be effectively used.

Further, there are provided dividing means for dividing the predetermined number sequence into a plurality of number sequences having a predetermined number of digits, and numerical conversion means for converting each number sequence generated by the dividing means into numerical values. By dividing means and digitizing means,
The route selection number unique to each trunk route is divided and converted into a set consisting of multiple numbers and registered, and the selection number notified from the calling side is divided from multiple numbers by the dividing means and digitizing means. The first group is converted into the first group and the second group consisting of a plurality of numerical values indicating the route selection number is sequentially read, and the numerical values forming the first and second groups are individually compared with each other. Since the selection number shown in the group and the route selection number shown in the second group are compared and the connection destination route is selected according to the comparison result, the digit of the numerical value that can be processed by the processor 11 Even if the number is smaller than the maximum number of digits in the selection number, it can be handled without any problem.

Further, the digit number of the third numerical value indicating all or part of the selection number notified from the calling side is changed to the fourth number indicating all or part of the route selection number registered as the route selection information. In the case of providing a digit aligning means for aligning with the number of digits of the third numerical value and comparing the third numerical value with the fourth numerical value, the digit aligning means changes the number of digits of the third numerical value into the digit of the fourth numerical value. Since the two are compared after they are arranged in the numbers, even if one route selection number is associated as a common connection destination corresponding to a plurality of selection numbers having several digits from the beginning, It becomes possible to select a connection destination route.

[Brief description of drawings]

FIG. 1 is a block diagram of an exchange according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing operations of a dividing unit and a digitizing unit.

FIG. 3 is an explanatory diagram showing route selection information.

FIG. 4 is an explanatory diagram showing an operation of a selection unit.

FIG. 5 is an explanatory diagram showing a general switching network.

FIG. 6 is an explanatory diagram showing conventional route selection information.

[Explanation of symbols]

1 ... exchange, 2, 6 ... trunk, 3, 7 ... outgoing register, 4, 8 ... incoming register, 5, 9 ... trunk route, 1
0 ... Call processing control section, 11 ... Processor, 12 ... Dividing means, 13 ... Numericalizing means, 14 ... Selection means, 15 ... Digit aligning means, 16 ... Memory, 17 ... Route selection information, 19 ... Maintenance terminal.

Claims (3)

[Claims] 1. A plurality of trunk routes connecting between exchanges are accommodated, and a storage means for storing a route selection number unique to each trunk route as route selection information is provided, and a call is made via an arbitrary trunk route. By converting the route selection information based on the selection number notified from the side, the specified number string is converted to a numerical value in the exchange that selects the specified trunk route as the connection destination route and connects to the calling side trunk route. The digitizing means is provided to convert the route selection number unique to each trunk route into a numerical value and pre-register it in the storage means as route selection information, and the calling side notifies the selection number. If this is the case, this selection number is converted into the first numerical value by the digitizing means, and the second numerical value indicating the route selection number is ordered from the route selection information registered in the storage means. Read Te, first number and the second
And a trunk route corresponding to the route selection number is selected as a connection destination route according to the comparison result. 2. A plurality of trunk routes connecting the exchanges are accommodated, and a storage means for storing a route selection number unique to each trunk route as route selection information is provided, and a call is made via an arbitrary trunk route. In the exchange that connects the caller side trunk route by selecting a predetermined trunk route as the connection destination route by searching the route selection information based on the selection number notified from the A dividing means for dividing the number sequence into a plurality of number sequences and a digitizing means for converting each number sequence generated by the dividing means into numerical values are provided, and the dividing means and the digitizing means uniquely identify each trunk route. Each route selection number is converted into a group consisting of multiple numbers and registered in advance in the storage means as route selection information. The calling side notifies the selection number. In this case, the selection number is divided by the dividing means and the digitizing means to be converted into a first set consisting of a plurality of numerical values, and a plurality of numerical values indicating the route selection number from the route selection information registered in the storage means. Sequentially read the second set of
The selection numbers shown in the first set and the route selection numbers shown in the second set are compared by individually comparing the numerical values that make up the first and second sets, and in accordance with the result of the comparison, A route selection method for an exchange characterized in that a trunk route corresponding to a route selection number is selected as a connection destination route. 3. The route selection method for an exchange according to claim 1, wherein the number of digits of a third numerical value indicating all or a part of the selection number notified from the calling side is registered as route selection information. When a digit aligning means for aligning the number of digits of the fourth numerical value indicating all or a part of the route selection number is provided and the third numerical value and the fourth numerical value are compared, the digit aligning means A method for selecting a route of an exchange, characterized in that the number of digits of the third numerical value is adjusted to the number of digits of the fourth numerical value and then the two are compared.