OSF DCE Administration Guide--Core Components

Appendix B. Object Identiﬁer Files

The X/Open Directory Service (XDS) interface offers client application programmers the

ability to create and maintain names in either CDS or GDS. Programmers can also create

new CDS attribute names or GDS attribute type labels. In the DCE Version 1.1

Directory Service, every CDS attribute name and GDS attribute type label has a

corresponding unique number called an object identiﬁer (OID).

CDS provides a method for translating between object identiﬁers and human-readable

names. This translation capability enables users to enter names instead of object

identiﬁers at the DCE control program (dcecp) interface. Also, dcecp displays the

names rather than object identiﬁers in command output. CDS attribute names and their

corresponding identiﬁers are stored in a ﬁle called cds_attributes. GDS attribute type

labels and their corresponding identiﬁers are stored in a ﬁle called cds_globalnames.

(See the and the OSF DCE Porting and Testing Guide for the full pathnames of all CDS

ﬁles.)

This appendix describes the contents and usage of both the cds_attributes and

cds_globalnames ﬁles and explains how application developers or directory service

managers can update the ﬁles with the object identiﬁers of new attributes.

B.1 Origin of Object Identiﬁers

The purpose of object identiﬁers is to ensure uniqueness among the attribute types that

many different applications generate and use. Object identiﬁers are typically obtained

from a hierarchy of allocation authorities, the highest being the International

Organization for Standardization (ISO) and the International Telegraph and Telephone

Consultative Committee (CCITT). Individual application developers do not usually have

to contact ISO or CCITT directly to obtain unique numbers. Application developers are

more likely to request object identiﬁers from a person within their company who is in

charge of allocating them. The company authority would in turn contact a higher

authority to obtain a unique company preﬁx.

The hierarchy of allocation authorities is indicated by dots that separate portions of an

object identiﬁer. Each string of numbers delineated by dots represents a level of the

allocation hierarchy, going left to right from the highest authority down. For example,

the object identiﬁer 1.3.22.1.1.2 consists of the following levels:

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