1、 ANSI/IEEE Std 802.5-1998E(Revision of ANSI/IEEE 802.5-1995)(Adopted by ISO/IEC and redesignated asISO/IEC 8802-5:1995)Information technologyTelecommunications and information exchange between systemsLocal and metropolitan area networksSpecic requirementsPart 5: Token ring access method and Physical
2、 Layer specicationsSponsorLAN MAN Standards Committeeof theIEEE Computer SocietyAdopted by the ISO/IEC and redesignated as ISO/IEC 8802-5: 1998EThe Institute of Electrical and Electronics Engineers, Inc.345 East 47th Street, New York, NY 10017-2394, USACopyright 1998 by the Institute of Electrical a
3、nd Electronics Engineers, Inc.All rights reserved. Published 1998. Printed in the United States of America.ISBN 1-55937-960-XNo 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.26 May 1998 SH
4、94536Abstract:This Local and Metropolitan Area Network standard, ISO/IEC 8802-5 : 1998, is part of afamily of local area network (LAN) standards dealing with the physical and data link layers asdefined by the ISO/IEC Open Systems Interconnection Basic Reference Model. Its purpose is toprovide compat
5、ible interconnection of data processing equipment by means of a LAN using thetoken-passing ring access method. The frame format, including delimiters, addressing, and prioritystacks, is defined. The medium access control (MAC) protocol is defined. The finite state machineand state tables are supplem
6、ented with a prose description of the algorithms. The physical layer(PHY) functions of symbol encoding and decoding, symbol time, and latency buffering are defined.The services provided by the MAC to the station management (SMT) and the services provided bythe PHY to SMT and the MAC are described. T
7、hese services are defined in terms of service prim-itives and associated parameters. The 4 and 16 Mbit/s, shielded twisted pair attachment of the sta-tion to the medium, including the medium interface connector (MIC), is also defined. Theapplications environment for the LAN is intended to be commerc
8、ial and light industrial. The use oftoken ring LANs in home and heavy industrial environments, while not precluded, has not beenconsidered in the development of the standard. A Protocol Implementation Conformance State-ment (PICS) proforma is provided as an annex to the standard.Keywords:data proces
9、sing interconnection, local area network (LAN), medium access control(MAC), token ringivCopyright 1998 IEEE. All rights reserved.ANSI/IEEE Std 802.5, 1998 EditionIEEE Standardsdocuments are developed within the Technical Committees of the IEEE Societies and theStandards Coordinating Committees of th
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21、cting inquiries intothe legal validity or scope of those patents that are brought to its attention.Copyright 1998 IEEE. All rights reserved.vIntroduction to ANSI/IEEE Std 802.5, 1998 Edition(This introduction is not a part of ANSI/IEEE Std 802.5, 1998 Edition or of ISO/IEC 8802-5 : 1998.)This standa
22、rd is part of a family of standards for local and metropolitan area networks. The relationshipbetween the standard and other members of the family is shown below. (The numbers in the figure refer toIEEE standard numbers.)This family of standards deals with the Physical and Data Link layers as define
23、d by the International Organi-zation for Standardization (ISO) Open Systems Interconnection (OSI) Basic Reference Model (ISO/IEC7498-1 : 1994). The access standards define seven types of medium access technologies and associatedphysical media, each appropriate for particular applications or system o
24、bjectives. Other types are underinvestigation.The standards defining the technologies noted above are as follows: IEEE Std 802Overview and Architecture.This standard provides an overview to the fam-ily of IEEE 802 Standards. ANSI/IEEE Std 802.1Band 802.1kISO/IEC 15802-2LAN/MAN Management.Defines an
25、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 802.1DISO/IEC 10038Media Access Control(MAC) Bridges.Specifies an architecture and protocol for the interconnection of IEEE 802 LANs below the
26、 MAC service boundary. ANSI/IEEE Std 802.1EISO/IEC 15802-4System Load Protocol.Specifies a set of services and protocol for those aspects of management concerned with the loading of systems on IEEE 802 LANs. ANSI/IEEE Std 802.1GISO/IEC 15802-5Remote Media Access Control(MAC) Bridging. Specifies exte
27、nsions for the interconnection, using non-LAN communication technologies, of geographically separated IEEE 802 LANs below the level of the logical link control protocol. ANSI/IEEE Std 802.2ISO/IEC 8802-2Logical Link Control ANSI/IEEE Std 802.3ISO/IEC 8802-3CSMA/CD Access Method and Physical Layer Sp
28、ecifications* Formerly IEEE Std 802.1A.DATALINKLAYERPHYSICAL802.2 LOGICAL LINK CONTROL802.1 BRIDGING802.1 MANAGEMENT802 OVERVIEW b) Defines the frame format, including the delimiters, address fields, information field, and frame-check sequence (FCS). Defines the Medium Access Control (MAC) frames, t
29、imers, and errorcounters (clause 3);c) Defines the MAC protocols including finite state machines and state tables (clause 4);d) Defines the system level Physical layer (PHY) signaling specifications that are specific to a ringstation (clause 5);e) Defines the managed objects necessary to manage the
30、service and protocol elements that areinvolved in the management of a token ring station (clause 6);f) Defines the PHY station attachment specification for 4 and 16 Mbit/s operation. This includes thetransmitter, receiver, medium interface connector, and transmission channel for both shieldedtwisted
31、 pair (STP) and unshielded twisted pair (UTP) media (clause 7);g) Defines the concentrator, incorporating multiple trunk coupling units ( TCUs), for the attachmentof a group of stations to the ring (clause 8);ISO/IEC 8802-5 : 1998 (E)ANSI/IEEE Std 802.5, 1998 Edition LOCAL AND METROPOLITAN AREA NETW
32、ORKS:2 Copyright 1998 IEEE. All rights reserved.h) Includes the protocol implementation conformance statement (PICS) proforma in compliancewith the relevant requirements, and in accordance with the relevant guidance, given in ISO/IEC9646-2 : 1994 1 (annex A);i) Includes channel design examples and f
33、ormulas for calculating cabling and conc entrator systemconfigur a tions (annex B);j) Describes jitter components and provides an example of jitter buildup using a phase lock looprecovery circuit (annex C);k) Provides informative transmitter filter design example (annex D);l) Provides recommended gu
34、idelines for safety and operating environments (annex E);m) Illustrates the MAC finite state machines in a notation similar to that used in ISO/IEC 8802-5 : 1992 (annex F);n) Describes major improvements made after the first edition of the standard (annex G);o) Provides a sample algorithm for the pa
35、rsing of MAC frames (annex H);p) Provides recommendations for the use of token ring access priorities to support multimedia traffic(annex I);q) Provides bit error rate (BER) criteria for lobe media testing (annex P).A particular emphasis of this standard is to specify the externally visible characte
36、ristics needed forinterconnection compatibility, while avoiding unnecessary constraints upon and changes to internaldesign and implementation of the heterogeneous processing equipment to be interconnected.The applications environment for the LAN is intended to be commercial and light industrial. The
37、 use oftoken ring LANs in home and heavy industrial environments, while not precluded, has not been consi d -ered in the develo p ment of this standard.This standard, the Third Edition of this part of ISO/IEC 8802, provides enhancements and corrections tothe Second Edition. The Second Edition provid
38、ed greater specificity and improved clarity to the FirstEdition (1992-06-12) to ensure interoperability of the various components in the token ring network. Theintent of this edition is to maintain interoperability with stations designed to this specification and stationsdesigned to prior editions o
39、f the standard. However, interoperability with prior implementations (partic u -larly in regard to clause 7) cannot be guaranteed due to nonspecificity within the 1992 edition. Annex Glists the specific differences between the second edition and the first edition.The following items are subjects for
40、 future study:a) Controlled bit altering by any device except a station.b) Methodology to assure handling of joining of multiple rings as may be used by managed conce n -trators to assure normal insertion process protection mechanisms (such as duplicate address test orring parameter server notificat
41、ion).c) Ring data rate determination to allow managed data rate adaptation between stations.d) Alternative active concentrators or repeaters that provide increased cabling distances and /orenhanced operation of rings containing devices built to the first edition of this standard, ISO/IEC8802-5 : 199
42、2.e) Converters that allow the interconnection of stations on different media types.f) Methodologies to provide enhanced transmission reliability over the trunk cable._1 Information on references can be found in 1.2.ISO/IEC 8802-5 : 1998 (E)TOKEN RING ANSI/IEEE Std 802.5, 1998 EditionCopyright 1998
43、IEEE. All rights reserved. 3g) Definition of concentrator managed objects.1.2 Normative referencesThe following standards contain provisions which, through reference in this text, constitute provisions ofthis part of ISO/IEC 8802. At the time of publication, the editions indicated were valid. All st
44、andards aresubject to revision, and parties to agreements based on ISO/IEC 8802-5 : 1998 are encouraged to invest i -gate the possibility of applying the most recent editions of the standards indicated below. Members of ISOand IEC maintain registers of currently valid International Standards.CISPR P
45、ublication 22 : 1985, Limits and Methods of Measurement of Radio Interference Characteristicsof Information Technology Equipment. 2IEC 6073 : 1996, Basic and safe ty principles for man-machine interface, marking and identification Coding principles for indicating devices and actuators. 3IEC 60603-7
46、: 1996, Connectors for frequencies below 3 MHz for use with printed boardsPart 7: Detailspecification for connectors, 8-way, including fixed and free connectors with common mating features,with assessed quality.IEC 60950 : 1991, Safety of information technology equipment.ISO/IEC 7498-1 : 1994, Infor
47、mation technologyOpen Systems InterconnectionBasic ReferenceModel: The Basic Model. 4ISO/IEC 7498-4 : 1989, Information processing systemsOpen Systems InterconnectionBasicReference ModelPart 4: Management framework.ISO/IEC 8802-2 : 1994 ANSI/IEEE Std 802.2, 1994 Edition, Information technologyTele-c
48、ommunications and information exchange between systemsLocal and metropolitan area networksSpecific requirementsPart 2: Logical link control. 5ISO/IEC 8824 : 1990, Information technologyOpen Systems InterconnectionSpecification of AbstractSyntax Notation One (ASN.1).ISO/IEC 9646-1 : 1994, Information
49、 technologyOpen Systems InterconnectionConformance testingmethodology and fram e workPart 1: General concepts.ISO/IEC 9646-2 : 1994, Information technologyOpen Systems InterconnectionConformance testingmethodology and fram e workPart 2: Abstract Test Suite specification.ISO/IEC 10038 : 1993 ANSI/IEEE Std 802.1D, 1993 Edition, Information technologyTele-communication and information exchange between systemsLocal area networksMedia access control(MAC) bridges._2 CISPR and IEC publications are available from the Internation
