IEEE-802.1G-1998.pdf

ANSI/IEEE Std 802.1G, 1998 Edition Adopted by ISO/IEC and redesignated as ISO/IEC 15802-5:1998(E) IEEE Standard for Information technology Telecommunications and information exchange between systems Local and metropolitan area networks Common specifications Part 5: Remote Media Access Control (MAC) bridging Sponsor LAN/MAN Standards Committee of the IEEE Computer Society Adopted by the ISO/IEC and redesignated as ISO/IEC 15802-5:1998(E) Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 07/30/2008 04:18:23 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 07/30/2008 04:18:23 MDTNo reproduction or networking permitted without license from IHS -,-,- Abstract: Extensions to the behavior of ISO/IEC 10038 (IEEE 802.1D) media access control (MAC) bridges, including the aspects of operation of remote MAC bridges that are observable on the interconnected LANs, are speciÞed. A protocol for (optional) use between remote MAC bridges, across the non-LAN communications equipment that interconnects them, to conÞgure the remote bridges within the bridged LAN in accordance with the spanning tree algorithm of ISO/IEC 10038: 1993, is also provided. Keywords: bridge management, local area network (LAN), local bridge, logical link control, media access control (MAC) bridges, remote bridge, spanning tree algorithm, spanning tree protocol The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA Copyright © 1998 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 1998. Printed in the United States of America. ISBN 1-55937-899-6 No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. 13 March 1998SH94504 Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 07/30/2008 04:18:23 MDTNo reproduction or networking permitted without license from IHS -,-,- iv Copyright © 1998 IEEE. All rights reserved. ANSI/IEEE Std 802.1G, 1998 Edition IEEE Standards documents are developed within the Technical Committees of the IEEE Societies and the Standards Coordinating Committees of the IEEE Standards Board. Members of the committees serve volun- tarily and without compensation. They are not necessarily members of the Institute. The standards developed within IEEE represent a consensus of the broad expertise on the subject within the Institute as well as those activities outside of IEEE that have expressed an interest in participating in the development of the standard. Use of an IEEE Standard is wholly voluntary. The existence of an IEEE Standard does not imply that there are no other ways to produce, test, measure, purchase, market, or provide other goods and services related to the scope of the IEEE Standard. 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The IEEE shall not be responsible for identifying patents for which a license may be required by an IEEE standard or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 07/30/2008 04:18:23 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright © 1998 IEEE. All rights reserved. v Introduction to ANSI/IEEE Std 802.1G, 1998 Edition (This introduction is not a part of ANSI/IEEE Std 802.1G, 1998 Edition or of ISO/IEC 15802-5: 1998.) This standard is part of a family of standards for local and metropolitan area networks. The relationship between the standard and other members of the family is shown below. (The numbers in the Þgure refer to IEEE standard numbers.) This family of standards deals with the Physical and Data Link layers as deÞned by the International Organiza- tion for Standardization (ISO) Open Systems Interconnection (OSI) Basic Reference Model (ISO/IEC 7498- 1: 1994). The access standards deÞne seven types of medium access technologies and associated physical media, each appropriate for particular applications or system objectives. Other types are under investigation. The standards deÞning the access technologies are as follows: ¥IEEE Std 802 Overview and Architecture. This standard provides an overview to the fam- ily of IEEE 802 Standards. ¥ANSI/IEEE Std 802.1B and 802.1k ISO/IEC 15802-2 LAN/MAN Management. DeÞnes an OSI management-compatible architec- ture, and services and protocol elements for use in a LAN/MAN environ- ment for performing remote management. ¥ANSI/IEEE Std 802.1D ISO/IEC 10038 Media Access Control (MAC) Bridges. SpeciÞes an architecture and protocol for the interconnection of IEEE 802 LANs below the MAC service boundary. ¥ANSI/IEEE Std 802.1E ISO/IEC 15802-4 System Load Protocol. SpeciÞes a set of services and protocol for those aspects of management concerned with the loading of systems on IEEE 802 LANs. ¥ANSI/IEEE Std 802.1G ISO/IEC 15802-5 Remote Media Access Control (MAC) Bridging . SpeciÞes extensions for the interconnection, using non-LAN communication technologies, of geographi- cally separated IEEE 802 LANs below the level of the logical link control protocol. ¥ANSI/IEEE Std 802.2 ISO/IEC 8802-2 Logical Link Control ¥ANSI/IEEE Std 802.3 ISO/IEC 8802-3 CSMA/CD Access Method and Physical Layer SpeciÞcations * Formerly IEEE Std 802.1A. DATA LINK LAYER PHYSICAL 802.2 LOGICAL LINK CONTROL 802.1 BRIDGING 802.1 MANAGEMENT 802 OVERVIEW it is only because of such differences that MAC bridge operation is not fully transparent. A bridged LAN can provide for The interconnection of stations attached to LANs of different MAC types. An effective increase in the physical extent, the number of permissible attachments, or the total performance of a LAN. Partitioning of the physical LAN for administrative or maintenance reasons. Local MAC bridges interconnect separate LANs, at geographically close points of attachment. Remote MAC bridges, which can be geographically separated, interconnect LANs sited locally to the individual remote MAC bridges, using non-LAN technologies for communication among the remote bridges. A given piece of equipment can be a local MAC bridge or remote MAC bridge, only, or it can combine the functions of a local MAC bridge and a remote MAC bridge. This International Standard extends ISO/IEC 10038: 1993,1 which specifies the operation of local MAC bridges, by specifying The aspects of operation of remote MAC bridges that are observable on the interconnected LANs, and A protocol for (optional) use between remote MAC bridges, across the non-LAN communications equipment that interconnects them, to configure the remote bridges within the bridged LAN in accordance with the Spanning Tree Algorithm of ISO/IEC 10038: 1993. To this end, it a)Extends the ISO/IEC 10038: 1993 architectural description of the MAC sublayer bridging function to cover interconnection of LANs by remote bridges (5.1). b)States the principles of operation of remote bridges in terms of the support and preservation of the MAC service, and of maintenance of quality of service (5.1, 5.2, 5.3). c)Extends the ISO/IEC 10038: 1993 definition of the MAC Internal Sublayer Service to apply to provision of the service by the non-LAN communications equipment that interconnects remote bridges (in addition to provision of the service by LANs, as covered in ISO/IEC 10038: 1993) (5.4). 1 Copyright © 1998 IEEE. All rights reserved. 1 Information on references can be found in Clause 2. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 07/30/2008 04:18:23 MDTNo reproduction or networking permitted without license from IHS -,-,- LOCAL AND METROPOLITAN AREA NETWORKS ISO/IEC 15802-5 : 1998(E) ANSI/IEEE Std 802.1G, 1998 Edition 2 Copyright © 1998 IEEE. All rights reserved. d)Extends the ISO/IEC 10038: 1993 model of the internal operation of a bridge to apply to remote bridges, and provides a related model for their interconnection (Clause 6). e)Specifies the behavior of remote bridges as observed on the LANs to which they are attached, both in relaying MAC frames between LANs and in supporting the Spanning Tree Protocol (Clauses 7 and 8). f)Specifies the requirements for provision of the MAC Internal Sublayer Service by the non-LAN communications equipment (5.6, Clause 8). g)Identifies managed objects for remote bridges, and defines the management operations on these objects (Clauses 9 and 10). h)Specifies performance requirements for remote bridges, and recommends default values and applicable ranges for operational parameters (7.10, Clause 11). i)Specifies an extension of the Spanning Tree Protocol for optional use over the non-LAN communications equipment that interconnects remote bridges (Clauses 12 and 13). j)Specifies requirements on the non-LAN communications equipment relating to support of the optional Extended Spanning Tree Protocol, in terms of an abstract subnetwork service that is to be provided by the non-LAN communications (12.2). k)Specifies the requirements to be satisfied by equipment claiming conformance to this International Standard (Clause 4). l)Provides the protocol implementation conformance statement (PICS) proforma in compliance with the relevant requirements, and in accordance with the relevant guidance, given in ISO/IEC 9646-7: 1995 (Annex A). Detailed specification of protocols and procedures to support either the MAC Internal Sublayer Service or the subnetwork service for support of the Extended Spanning Tree Protocol, over particular non-LAN communication technologies, is outside the scope of this International Standard. Annex B summarizes the object identifier values allocated by this International Standard. Annex C contains additional explanatory and tutorial material, intended to aid the reader in understanding a number of aspects of remote MAC bridging that were highlighted during the development of this International Standard. Annex D summarizes the relationship of the material in this International Standard to ISO/IEC 10038: 1993. NOTEThis International Standard is closely based upon the specification for local MAC bridging in ISO/IEC 10038: 1993, and the text largely follows the organization of that parent standard. However, dealing with remote bridging introduces the need for a number of new concepts, with associated protocol parameters and mechanisms, etc. Annex D identifiesat clause and subclause level, and occasionally still more preciselythe correspondences and differences between this International Standard and ISO/IEC 10038: 1993. In particular, it lists subclauses that contain significant new or modified requirements specific to remote MAC bridging. 2. References The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards listed below. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 07/30/2008 04:18:23 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE Std 802-1990, IEEE Standards for Local and Metropolitan Area Networks: Overview and Architecture (ANSI).2 IEEE Std 802.1j-1996 (Supplement to IEEE Std 802.1D