Attribute

Arthur Foster

Hillman House, 4, Madeira Road,

Parkstone, Poole, Dorset BH14 9ET

Description of GDMO
Attribute

e-mail:	arthur@arthurfoster.com
tel:	+44 (01202) 469468
fax:	+44 (01202) 469861

Attribute Example
Get Operation
Set Operation

The ATTRIBUTE template is used to define the syntax and general semantics of attribute types. The attribute templates specifies the syntax of the information carried in various CMIP Operations and specifically GET and SET operations.

The precise way in which an particular attribute is employed in a particular managed object is specified by the properties of the package containing the attribute.

        name ATTRIBUTE
                WITH ATTRIBUTE SYNTAX   reference;
                MATCHES FOR  qualifier ;
                BEHAVIOUR   behaviour  ....;
                PARAMETERS   parameter ... ;
        REGISTERED AS  object identifier;

The WITH ATTRIBUTE SYNTAX reference specifies an ASN.1 type definition. The reference identifies a ASN.1 production that defines the syntax of information. The reference consists of an ASN.1 module containing the production and is followed by the name of the ASN.1 production. Since ASN.1 types are never defined in-line, this is always a reference to another document or section of a document. An alternative to a reference to an ASN.1 production is to derive this attribute from another attribute. This clause is mandatory.

The MATCHES FOR qualifier clause defines the matches that can be performed on this attribute. The possible types of matches are:

	EQUALITY
	ORDERING
	SUBSTRING
	SET-COMPARISON
	SET-INTERSECTION

The behaviour identifier in BEHAVIOUR clause identifies a behaviour template that specifies the associated behaviour. The behaviour definition is optional.

The behaviour of the attribute can be qualified by the parameters - especially error conditions.

The REGISTERED AS object identifier is a unique identity that is used in the protocol to identify this particular attribute type.

Qualifier Definitions:

If the EQUALITY qualifier is present, then the attribute may be tested for equality against a given value.

If the ORDERING qualifier is present, then the attribute may be tested against a given value to determine which is the greatest value.

If the SUBSTRING qualifier is present, then the attribute may be tested against a given sub-string value to determine if the sub-string value is a present or absent in the attribute value.

If the SET-COMPARISON qualifier is present, then the attribute may be tested against a given value to determine the subset/superset relationships between the two values.

If the SET-INTERSECTION qualifier is present, then the attribute may be tested against a given value to determine the presence of the non-null set intersection between the two values.


Author: Arthur Foster 28 May 2002	Arthur Foster is a founder member of
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