Jump to content

ISO 8583: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
rm blank space
Line 119: Line 119:
The bitmap may be transmitted as 8 bytes of binary data, or as 16 bytes of hexadecimal characters 0-9, A-F in the ASCII or EBCDIC character sets.
The bitmap may be transmitted as 8 bytes of binary data, or as 16 bytes of hexadecimal characters 0-9, A-F in the ASCII or EBCDIC character sets.


=== Examples ===
Ї=== Examples ===efasdfaasfdasfd


{| class="wikitable"
{| class="wikitable"

Revision as of 02:49, 1 August 2007

ISO 8583 Standard for Financial Transaction Card Originated Messages - Interchange message specifications is the International Organization for Standardization standard for systems that exchange electronic transactions made by cardholders using payment cards.

Message Type Indicator (MTI)

This is a 4 digit numeric field which classifies the high level function of the message. A Message Type Indicator includes the ISO 8583 version, the Message Class, the Message Function and the Message Origin, each described briefly in the following sections.

ISO 8583 Version

Position one of the MTI specifies the versions of the ISO 8583 standard which is being used to transmit the message.

Position Meaning
0xxx ISO 8583-1:1987 version
1xxx ISO 8583-2:1993 version
2xxx ISO 8583-1:2003 version
9xxx Private usage

Message Class

Position two of the MTI specifies the overall purpose of the message.

Position Meaning Usage
x1xx Authorization Message Determine if funds are available, get an approval but do not post to account for reconciliation, Dual Message System (DMS) system, awaits file exchange for posting to account
x2xx Financial Message Determines if funds are available, get an approval and post directly to the account, Single Message System (SMS), no file exchange after this
x3xx File Actions Message Used for hot-card, TMS and other exchanges
x4xx Reversal Message Reverses the action of a previous authorization
x5xx Reconciliation Message Transmits settlement information
x6xx Administrative Message Transmits information about message failures
x7xx Fee Collection Message
x8xx Network Management Message Used for secure key exchange, logon, echo test and other network functions
x9xx Reserved by ISO

Message Function

Position three of the MTI specifies the message function which defines how the message should flow within the system. Requests are end-to-end messages (eg, from acquirer to issuer and back with timeouts and automatic reversals in place), while advices are point-to-point messages (eg, from terminal to acquirer, from acquirer to network, from network to issuer, with transmission guaranteed over each link, but not necessarily immediately).

Position Meaning
xx0x Request
xx1x Request Response
xx2x Advice
xx3x Advice Response
xx4x Notification
xx8x Response acknowledgment
xx9x Negative acknowledgment

Message Origin

Position four of the MTI defines the location of the message source within the payment chain.

Position Meaning
xxx0 Acquirer
xxx1 Acquirer Repeat
xxx2 Issuer
xxx3 Issuer Repeat
xxx4 Other
xxx5 Other Repeat

Examples

Bearing each of the above four positions in mind, an MTI will completely specify what a message should do, and how it is to be transmitted around the network. Unfortunately, not all ISO 8583 implementations interpret the meaning of an MTI in the same way. However, a few MTI's are relatively standard:

MTI Meaning Usage
0100 Authorization request Request from a point-of-sale terminal for authorization for a cardholder purchase
0101 Repeat Request
0200 Acquirer Financial Request Request for funds, typically from an ATM
0400 Acquirer Reversal Request Reverses a transaction
0401 Reversal Repeat Message
0420 Acquirer Reversal Advice Advises that a reversal has taken place
0800 Network Management Request Echo test, logon, log off etc

Bitmaps

Within ISO 8583, a bitmap is a field or subfield within a message which indicates which other data elements or data element subfields may be present elsewhere in a message.

A message will contain at least one bitmap, called the Primary Bitmap which indicates which of Data Elements 1 to 64 are present. A secondary bitmap may also be present, generally as data element one and indicates which of data elements 65 to 128 are present. Similarly, a tertiary, or third, bitmap can be used to indicate the presence or absence of fields 129 to 192, although these data elements are rarely used.

The bitmap may be transmitted as 8 bytes of binary data, or as 16 bytes of hexadecimal characters 0-9, A-F in the ASCII or EBCDIC character sets.

Ї=== Examples ===efasdfaasfdasfd

Bitmap Defines presence of
4210001102C04804 Fields 2, 7, 12, 28, 32, 39, 41, 42, 50, 53, 62
7234054128C28805 Fields 2, 3, 4, 7, 11, 12, 14, 22, 24, 26, 32, 35, 37, 41, 42, 47, 49, 53, 62, 64
8000000000000001 Field 1, 64
0000000000000011
(secondary bitmap)
Fields 124, 128

Data Elements

Data Elements are the individual fields which carrying the substantive information about the transaction itself. There are up to 128 data elements specified in the original ISO 8583:1987 standard, and up to 192 data elements in later releases. The 1993 revision added new definitions, deleted some, while leaving the message format itself unchanged.

While each data element has a specified meaning and format, the standard also includes some general purpose data elements and system- or country-specific data elements which vary enormously in use and form from implementation to implementation.

Each data element is described in a standard format which defines the permitted content of the field (numeric, binary, etc) and the field length (variable or fixed), according to the following table:

Abbreviation Meaning
a Alpha, including blanks
n Numeric values only
s Special characters only
an Alphanumeric
as Alpha & special characters only
ns Numeric and special characters only
ans Alphabetic, numeric and special characters.
b Binary data
z Tracks 2 and 3 code set as defined in ISO 4909 and ISO 7813.

Additionally, each field may be either fixed or variable length. If variable, the length of the field will be preceded by a length indicator.

Type Meaning
Fixed Fixed length
LVAR or (..x) Where x < 10, means one leading digit specifies the field length
LLVAR or (..xx) Where xx < 100, means two leading digits specify the field length
LLLVAR or (..xxx) Where xx < 1000, means three leading digits specify the field length

Examples

Field Definition Meaning
n6 Fixed length field of six digits
n. .6 LVAR numeric field of up to 6 digits in length
a. .11 LLVAR alphanumeric field of up to 11 characters in length
b. .999 LLLVAR binary field of up to 999 bytes in length