RFC 1804 (rfc1804) - Page 2 of 10
Schema Publishing in X
Alternative Format: Original Text Document
RFC 1804 Schema Publishing in X.500 Directory June 1995
1. Introduction
The X.500 Directory [1] is now used for a wide range of applications
from name/address lookup to network management, from restaurant
information to bibliographic information services. This information
is distributed and managed across a network of many autonomous sites.
In order to interpret the information stored in the directory, the
components of the directory must have knowledge about the structure
and representation (schema) of the information held within the
directory.
The distributed nature of the network and the relatively slow process
of standardization have given rise to the challenging task of making
accessible the information about the schema rules themselves. A
mechanism for making the schema accessible to the functional
components of the directory is urgently required.
The 1993 X.500 Directory Standard [2] has attempted to address the
problem of schema management and distribution. The 1993 framework
does provide the means for storing and retrieving schema information
in the directory. However, the resolution of unknown OIDs will
require both the DUA and the DSA to be compliant with [2].
In this document we propose a solution using the existing mechanisms
of the directory [1] itself. We present a naming scheme for naming
schema objects and a meta-schema for storing schema objects in the
directory. The proposal allows the algorithmic resolution of unknown
objects in the directory and in the absence of 1993 X.500 Directory
Standard implementations provides an interim solution to the schema
publishing problem.
2. Schema Management
The storage and retrieval mechanism provided by the directory is
powerful and flexible. However, the key to the directory is the
knowledge of the schema rules defined for the objects represented in
the directory. To facilitate the diffusion of this knowledge
appropriate schema management mechanisms need to be designed. Schema
management involves:
o Storage of schema information in the directory
o Algorithmic access to and retrieval of schema information
in the directory
o Definition of rules for schema modification
o Propagation of schema information from one component of the
directory to other components of directory
Mansfield, et al Experimental