ISO/IEC INTERNATIONAL STANDARD 8825-3 Fourth edition 2021-06 Information technology AsN.1 encoding rules - Part 3: Specification of Encoding Control Notation (ECN) Technologies de I'information - Regles de codage ASN.1 - Partie 3: Speécification de la notation de controle de codage (ECN) Reference number IEC IS0/IEC 8825-3:2021(E) Tso @IS0/IEC2021 IS0/IEC 8825-3:2021(E) COPYRIGHT PROTECTED DOCUMENT @IS0/IEC2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either Iso at the address 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:+4122 749 0111 Email: [email protected] Website:www.iso.org Published in Switzerland ii @ IS0/IEC 2021 - All rights reserved IS0/IEC 8825-3:2021(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. This document was drafted in accordance with the editorial rules of the Iso/IE Directives, Part2 (see www.iso.org/directives or www.iec.ch/members experts/refdocs) 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 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. In the IEC, see www.iec.ch/understanding-standards. This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 6, Telecommunications and information exchange between systems, in collaboration with ITU-T. The identical text is published as ITU-T X.692 (02/2021). This fourth edition cancels and replaces the third edition (IS0/IEC 8825-3:2015), which has been technically revised. A list of all parts in the ISO/IEC 8825 series can be found on the ISO and IEC websites. 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 and www.iec.ch/national. committees. @ IS0/IEC 2021 - All rights reserved iii IS0/IEC 8825-3:2021(E) CONTENTS Page Introduction .... 1 Scope... 2 2.1 Identical Recommendations I International Standards 2.2 Additional references.. 3 3.1 ASN.1 definitions.. 3.2 ECN-specificdefinitions 4 Ab