Table of Contents - APTAStandards.com

defines instruction, notification and advice message types for unique operating
conditions. “Request-Response” message pairs were originally intended for exchange
between an operator central system and a regional central system. However,
depending on the system architecture, the message pairs can be configured for
exchange between two operator central systems.
Operator Central
System
4.1.7 Security Requirements
Exhibit 4.1-5 Request Response Pair
Regional Central
System
Request/Response Request/Response
Request/Response
Operator Central
System
The standard mandates th e last bit position within any message bit map to be reserved
for
the Message Authentication Code (MAC) data element to validate
the source and
the
text of the message between the sender and the receiver. The standard also makes
reference to ISO/IEC 9807 (Banking and Related Financial Services) for message
authentication.
4.1.8 Timing & Routing
ISO Standard 8583 defines two alternative information exchange schemes including
examples to accommodate transfer of data, in a batch or a file transfer format, in
addition to the standard real-time “request-response” messages. These alternative
approaches can be especially beneficial in a back-end information exchange, where a
real time transfer of data to the higher tier or the central system is not as critical. These
two alternatives provide a viable foundation for information exchange between both
intra
agency system components and different central systems that operate on a peer-topeer
basis. Therefore these exchange schemes are applicable to the UTFS efforts.
ISO/IEC 8583 describes a file transfer process that is designed to allow transfer of larger
volumes of data in the minimum number of messages. The file transfer consists of
submission of a group of file action messages (300 series), where the total number of
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