Simulating The Global Directory Service With OPNET

Abstract

his paper describes the use of the OPNET simulation package to build a model of the global directory service. Ihe global directory service is bas& on the modek and data structures described in the joint ISO/CCIlTStandard - X 500: Ihe Directory. model. The standard describes how the data in the database is to be constructed. It also specifies a schema that can be used to control actual data stored in a live system. Most importantly, from the Perspective of the current research, the standard describes how the global database is to be distributed between application proceases worldwide. Section 2 gives a brief summary of how this is achieved. More detailed explanations can be found in papers by Chadwick (2,3) and Radacati (4), or in the Standard itself. The original version of the standard, finalised in 1988, did not support replication of the data between the application processes (called Directory System Agents, or DSAs). This model is due to be finalised in October 1992. Replication is expected to significantly enhance the performance of the Directory, but by how much has not been quantified.