OSI/FTAM Programming Reference Manual

Conformance and Interoperability
HP NonStop OSI/FTAM Programming Reference Manual—528611-001
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Data Transfer Considerations
NonStop FTAM supports unbounded strings for FTAM-1 (string-significance: not
significant or variable) and FTAM-3 (string-significance: not significant).
For string-significance, the initiator supports all three possible values for the FTAM-1,
FTAM-2, and FTAM-3 document types: not-significant, fixed, and variable.
For the universal-class parameter associated with FTAM-1 and FTAM-2
document types (the concept of universal-class does not apply to FTAM-3 documents),
the initiator supports the universal-class values specified in Tables 19 and 20 of ISO
8571, Part 2. If no universal-class value is proposed in an initiator open request or
returned in an open confirm, the NonStop FTAM initiator assumes that the responder is
sending GraphicString data, in compliance with the ISO 8571 default for the universal-
class parameter value.
For more information on NonStop FTAM document types and their associated
parameters, see the OSI/FTAM Programming Guide.
Data Transfer Considerations
This subsection briefly describes the aspects of NonStop FTAM data handling that
might affect interoperability between the NonStop FTAM initiator and another FTAM
implementation. For complete information, see the OSI/FTAM Programming Guide.
Handling of Escape Sequences
In enforcing maximum-string-length, when the initiator receives data from a remote
responder, it strips out all escape sequences embedded in character strings with a
negotiated universal-class of 25 (GraphicString) or 27 (GeneralString). Any escape
sequences invoking different character sets that the file might have originally contained
are eliminated from the data before it is passed up to the local FTAM application.
Use of Format Effectors
Format effectors are characters such as carriage returns and line feeds, which control
the formatting of information on character-imaging devices. To interoperate
successfully, application programmers must understand what an implementation
expects as an end-of-line symbol and how it interprets format effectors. For example,
some implementations use the FTAM-1 document type to transfer binary data as
opposed to text. Some implementations recognize carriage returns and line feeds as
format effectors and discard them when binary data, not text, is being transferred;
others see the format effectors as data and transfer them as such.
Character Sets
The NonStop FTAM initiator does no character-set verification. For FTAM-1 and
FTAM-2 files, to ensure that the file being transferred contains the correct character
string type as specified in the universal-class parameter, your application should
verify characters as it sends or receives the data. For more information, see ISO 8824,
which defines character-string types.