Nortel DMS-100 TOPS Domestic Credit Card Check Digit Table (CHKDIGIT) |
Table Name
Traffic Operator Position System Domestic Credit Card Check Digit Table
Functional Description of Table CHKDIGIT
Table CHKDIGIT performs a special digit check that compares one of the last four digits of the 14-digit domestic credit card or portable special billing number against a designated check digit in the number. The last four digits are of the format XXXX, representing a Personal Identification Number (PIN) with any one of the four digits designated a check digit (specified in field CHKDGPOS).
Each year, the seventh, eighth, ninth, or tenth digit is designated as the check digit and a number (0 to 9) is assigned to each of the numerics 0 to 9 to which the check digit may be equal. A valid credit card or special billing number is one that has the correct value in XXXX to match the value of the check digit. When the match is found during the special digit check the DMS Traffic Operator Position System (TOPS) proceeds to the next check.
Conversely, a mismatch indicates an invalid domestic credit card or special billing number. If this occurs, the credit card number shown on the TOPS flashes off and on to notify the TOPS operator of the mismatch.
As of BCS9, two other tables (RAOCHECK and NPACHECK) are used to define RAOs and Numbering Plan Areas (NPA) to be checked using table CHKDIGIT. For related information, refer to table HOTLIST (TOPS Domestic Hot List).
Datafill Sequence & Size
There is no requirement to datafill other tables prior to table CHKDIGIT. Table size is 0 to 2 tuples.
Datafill
The following table describes datafill for table CHKDIGIT:
----------------------------------------------------------------------------------------------
Table CHKDIGIT Field Descriptions
Field Subfield Entry Explanation and Action
----------------------------------------------------------------------------------------------
PERIOD PRESENT or PREVIOUS Period
Enter PRESENT or PREVIOUS to specify the
year to which the special digit check
applies.
At the end of each year, transfer the
information in the PRESENT record to the
PREVIOUS record, then enter the
information that applies to the new year
in the PRESENT record.
---------------------------------------------------------------------------------------------
VERDGPOS 7 to 10 Verification Digit Position
Enter the position of the verification
digit.
----------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------
CHKDGPOS 11 to 14 Check Digit Position
Enter the position of the check digit.
----------------------------------------------------------------------------------------------
VAL0 to VAL9 0 to 9 Value
Enter in fields VAL0 to VAL9 the value
that the Nth digit of the credit card or
special billing number must be when the
value of the check digit is equal to 0
to 9, where 'n' is the entry in field
CHKDGPOS.
----------------------------------------------------------------------------------------------
-End-
Datafill Example
The following example MAP display shows sample datafill for table CHKDIGIT.
The 14th digit of the present year credit card or special billing number must be equal to 2, 1, 5, 6, 0, 9, 7, 4, 3, or 8 when the 7th digit of the present year credit card number is equal to 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 respectively.
The 11th of the 14-digit previous year credit card or special billing number must be equal to 5, 9, 2, 7, 1, 4, 0, 6, 8, or 3 when the 9th digit of the previous year credit card number is equal to 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 respectively.
Note: 41444453333338 is an invalid present year credit card number because its 7th digit is equal to 5, and in PRESENT period, the entry in field CHKDGPOS is 14, indicating that the last digit of the credit card number is the check digit and its value (8) should match the value of VAL5, which is 9.
PERIOD VERDGPOS CHKDGPOS VAL0 VAL1 VAL2 VAL3 VAL4 VAL5 VAL6 VAL7 VAL8 VAL9 _______________________________________________________________________________________ PRESENT 7 14 2 1 5 6 0 9 7 4 3 8 PREVIOUS 9 11 5 9 2 7 1 4 0 6 8 3 |