OSI/MHS Gateway Programmatic Interface (GPI) Programming Guide

GPI Object Management
OSI/MHS Gateway Programmatic Interface (GPI) Programming Guide—424822-001
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Attribute Value
Attribute Value
Attribute value is a specific instance of attribute type. For example, the value for United
States (“US”) is an instance of the MH-T-COUNTRY-NAME attribute. Attribute value
takes the form specified by attribute syntax.
Attribute Descriptors
An attribute descriptor is the data structure used to pass a single value of an attribute
between the client and the GPI service. The information that is passed includes:
•
The attribute type and syntax associated with that value
•
The value itself
Descriptors have two fields of 16 bits each and two fields of 32 bits each (Figure 3-9).
The first two fields contain an attribute’s type and syntax. The third and fourth fields
contain a single value of the attribute. The format of the third and fourth fields varies,
depending on the value’s syntax. For details, refer to the GPI Reference Manual.
In this example, the descriptor contains information for an attribute associated with the
MH-C-G3-FAX-NBPS class. This particular attribute indicates whether a fax image
requires B4 width. The syntax is OM-S-BOOLEAN, and the value is OM-TRUE,
indicating B4 width is required. Also shown are integer values for the type, syntax, and
value. Note that, for this syntax, the value is contained solely in the third field.
Table 3-3. Attribute Syntaxes
Syntax Values Represented
Boolean TRUE or FALSE.
Enumeration Any of a specified set.
Integer The positive and negative integers represented in 32 bits.
Object Object identifier of a specified class.
String Any of the following well-defined strings: bit, encoding, IA5, numeric, object
descriptor, object identifier, octet, printable, teletex, UTC time, videotex (each
has its own constant).
Figure 3-9. Attribute Descriptor
309CDT .CDD
OM-TRUE
215 1 1
(16 bits) (16 bits) (32 bits) (32 bits)
-
Type
Syntax
Value
MH-T-B4-WIDTH OM-S-BOOLEAN