Implementing the Directory

The OSI Directory has recently been jointly standardised as CCITT X.500 Series Recommendations and ISO 9594 [CCI88]. A natural application of the Directory is to provide a global service to look up information about people or OSI applications-the majority of examples in the standard are formulated with respect to this sort of service. A number of practical developments which are moving towards provision of an open and distributed directory are discussed. Implementing the Directory is discussed both in terms of implementing components, and integrating them together to implement a service. A prerequisite to any practical investigation or use of the Directory is the availability of implementations of Directory User Agents (DUAs) and Directory System Agents (DSAs). Two implementations of the Directory, and their key features are described. Then, the application of these systems into two directory pilots is described. Finally, some of the problems and implications of this work are considered