August 13, 1992 About these notes...

This paper briefly summarizes the functionality provided by the X.500 Directory (i.e., the CCITT X.500 international standard, also known as ISO 9594 [1], [2]). The objective here is to give some general insight into the services and capabilities of the X.500 database (hereafter referred to as the Directory), while maintaining brevity. The paper is targeted at a general audience, and assumes no prior knowledge of Open Systems Interconnection standards or data communications. The intent of the paper is to acquaint a wider audience with the existence of the Directory, and thereby to spur broader use of the technology. Overview of the Directory The Directory constitutes an internationally standardized, distributed database system. It combines an object-oriented approach to the storage of information about real world entities with the potential for indefinite expansion in the size of the database and the number of servers it comprises. The distributed nature of the Directory is transparent to the user, allowing for consistent results regardless of the geographic location of data. A powerful query mechanism is provided, as are mechanisms for controlling access to information, authenticating users, and various efficiency mechanisms. Standardized Protocols The Directory standard is a member of the set of Open Systems Interconnection (OSI) data communications standards, and as such is inherentl