ISO/IEC INTERNATIONAL 9594-1 STANDARD Ninth edition 2020-11 Information technology Open systems interconnection - Part 1: The Directory: Overview of concepts, models and services Reference number ISO/IEC 9594-1:2020(E) IEC ISO @ IS0/IEC 2020 IS0/IEC 9594-1:2020(E) COPYRIGHT PROTECTED DOCUMENT IS0/IEC2020 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may below or ISo's member body in the country of the requester. ISO copyright office CP 40i : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland ii IS0/IEC2020-Allrightsreserved IS0/IEC 9594-1:2020(E) Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of IsO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISo and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with IsO and IEC, also take part in the work. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of document should be noted (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC list of patent declarations received (see http://patents.iec.ch). Any trade name used in this document is information given for the convenience of users and does not constituteanendorsement. For an explanation of the voluntary nature of standards, the meaning of IsO specific terms and expressions related to conformity assessment, as well as information about Iso's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html This document was prepared by ITU-T as ITU-T X.500 (10/2019) and drafted in accordance with its editorial rules, in collaboration with Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee sC 6, Telecommunications and information exchange between systems. This ninth edition cancels and replaces the eighth edition (IS0/IEC 9594-1:2017), which has been technically revised. A list of all parts in the ISO/IEC 9594 series can be found on the ISO website. Any feedback or questions on this document should be directed to the user's national standards body. A complete listing of these bodies can be found at www.iso.org/members.html. @ IS0/IEC 2020 - All rights reserved iii