1、IEEE Std 802.1Qau-2010(Amendment toIEEE Std 802.1Q-2005) IEEE Standard forLocal and metropolitan area networks Virtual Bridged Local Area NetworksAmendment 13: CongestionNotificationIEEE Computer SocietySponsored by theLAN/MAN Standards CommitteeIEEE3 Park Avenue New York, NY 10016-5997, USA 23 Apri
2、l 2010802.1QauTMIEEE Std 802.1Qau-2010(Amendment to IEEE Std 802.1Q-2005)IEEE Standard for Local and metropolitan area networksVirtual Bridged Local Area NetworksAmendment 13: Congestion NotificationSponsorLAN/MAN Standards Committeeof theIEEE Computer SocietyApproved 25 March 2010IEEE-SA Standards
3、BoardAbstract: This amendment specifies protocols, procedures and managed objects that supportcongestion management of long-lived data flows within network domains of limited bandwidth-delayproduct. This is achieved by enabling bridges to signal congestion to end stations capable oftransmission rate
4、 limiting to avoid frame loss.Keywords: congestion, congestion notification, LANs, local area networks, MAC Bridges,transparent bridging, VLANsThe Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2010 by the Institute of Electrical and Elect
5、ronics Engineers, Inc.All rights reserved. Published 23 April 2010. Printed in the United States of America.IEEE and 802 are registered trademarks in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educationalclassroom use can also be obtained through
6、 the Copyright Clearance Center.iv Copyright 2010 IEEE. All rights reserved.IntroductionThis standard amends IEEE Std 802.1Q-2005, providing congestion notification capabilities useful toVirtual Bridged Local Area Networks to support congestion management of long-lived data flows withinnetwork domai
7、ns of limited bandwidth-delay product. Congestion notification mechanisms defined in thisstandard include the following:a) The ability of bridges and end stations to create Congestion Notification Domains for certainpriority levels by signaling using the Link Layer Discovery Protocol defined in IEEE
8、 Std802.1AB-2009.ab) The ability for bridges to use priority remapping to automatically defend a Congestion NotificationDomain against sources that are not aware of congestion notification.c) Mechanisms by which bridges detect the congestion state of specified output queues, and sendCongestion Notif
9、ication Messages to the sources of a sampling of the frames in the queue.d) Mechanisms by which an end station responds to Congestion Notification Messages by stopping,increasing, decreasing, or disabling control of the rate of output for frames.e) A set of managed objects to provide controls for th
10、ese capabilities in both bridges and end stations.This standard contains state-of-the-art material. The area covered by this standard is undergoing evolution.Revisions are anticipated within the next few years to clarify existing material, to correct possible errors, andto incorporate new related ma
11、terial. Information on the current revision state of this and other IEEE 802standards can be obtained fromSecretary, IEEE-SA Standards Board445 Hoes LanePiscataway, NJ 08854USANotice to usersLaws and regulationsUsers of these documents should consult all applicable laws and regulations. Compliance w
12、ith theprovisions of this standard does not imply compliance to any applicable regulatory requirements.Implementers of the standard are responsible for observing or referring to the applicable regulatoryrequirements. IEEE does not, by the publication of its standards, intend to urge action that is n
13、ot incompliance with applicable laws, and these documents may not be construed as doing so. aInformation of references can be found in Clause 2.This introduction is not part of IEEE Std 802.1Qau-2010, IEEE Standard for Local and Metropolitan AreaNetworksVirtual Bridged Local Area NetworksAmendment 1
14、3: Congestion Notification.Copyright 2010 IEEE. All rights reserved. vCopyrightsThis document is copyrighted by the IEEE. It is made available for a wide variety of both public and privateuses. These include both use, by reference, in laws and regulations, and use in private self-regulation,standard
15、ization, and the promotion of engineering practices and methods. By making this documentavailable for use and adoption by public authorities and private users, the IEEE does not waive any rights incopyright to this document.Updating of IEEE documentsUsers of IEEE standards should be aware that these
16、 documents may be superseded at any time by theissuance of new editions or may be amended from time to time through the issuance of amendments,corrigenda, or errata. An official IEEE document at any point in time consists of the current edition of thedocument together with any amendments, corrigenda
17、, or errata then in effect. In order to determine whethera given document is the current edition and whether it has been amended through the issuance ofamendments, corrigenda, or errata, visit the IEEE Standards Association website at http:/ieeexplore.ieee.org/xpl/standards.jsp, or contact the IEEE
18、at the address listed previously.For more information about the IEEE Standards Association or the IEEE standards development process,visit the IEEE-SA website at http:/standards.ieee.org.ErrataErrata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee
19、.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL forerrata periodically.InterpretationsCurrent interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/index.html.PatentsAttention is called to the possibility that implement
20、ation of this amendment may require use of subjectmatter covered by patent rights. By publication of this amendment, no position is taken with respect to theexistence or validity of any patent rights in connection therewith. The IEEE is not responsible for identifyingEssential Patent Claims for whic
21、h a license may be required, for conducting inquiries into the legal validityor scope of Patents Claims or determining whether any licensing terms or conditions provided in connectionwith submission of a Letter of Assurance, if any, or in any licensing agreements are reasonable or non-discriminatory
22、. Users of this amendment are expressly advised that determination of the validity of anypatent rights, and the risk of infringement of such rights, is entirely their own responsibility. Furtherinformation may be obtained from the IEEE Standards Association.vi Copyright 2010 IEEE. All rights reserve
23、d.ParticipantsAt the time this amendment was submitted to the IEEE-SA for approval, the IEEE 802.1 Working Grouphad the following membership: Tony Jeffree, Chair Paul Congdon, Vice ChairNorman Finn, EditorPatricia Thaler, Chair, Data Center Bridging Task GroupZehavit Alon Ting Ao Siamack Ayandeh Jan
24、 Bialkowski Jean-Michel Bonnamy Paul Bottorff Rudolf Brandner Craig Carlson Weiying Cheng Rao Cherukuri Don Connor Diego Crupnicoff Claudio Desanti Zhemin Ding Linda Dunbar Donald Eastlake, III Janos Farkas Donald Fedyk Robert Frazier John Fuller Geoffrey Garner Anoop Ghanwani Franz Goetz Eric Gray
25、Craig Gunther Mitch Gusat Stephen Haddock Asif Hazarika Charles Hudson Romain Insler Pankaj Jha Abhay Karandikar Hal Keen Yongbum Kim Philippe Klein Michael Krause Vinod Kumar Bruce Kwan Kari Laihonen Ashvin Lakshmikantha John Lemon Marina Lipshteyn Yuanqiu Luo Ben Mack-Crane Menucher Menuchery John
26、 Messenger Gabriel Montenegro John Morris Eric Multanen Paul Nikolich Kevin Nolish David Olsen Vijoy Pandey Donald Pannell Glenn Parsons Joseph Pelissier David Peterson Hayim Porat Karen Randall Josef Roese Derek Rohde Dan Romascanu Jessy Rouyer Ali Sajassi Joseph Salowey Panagiotis Saltsidis John S
27、auer James Scott Michael Seaman Koichiro Seto Rakesh SharmaTaeshi Shimizu Nurit Sprecher Kevin Stanton Robert Sultan Muneyoshi Suzuki Michael Johas Teener Paul Unbehagen Manoj Wadekar Yuehua Wei Brian Weis Martin White Bert Wijnen Robert Winter Chien-Hsien Wu Ken Young Glen Zorn Copyright 2010 IEEE.
28、 All rights reserved. viiThe following members of the individual balloting committee voted on this standard. Balloters may havevoted for approval, disapproval, or abstention. When the IEEE-SA Standards Board approved this standard on 25 March 2010, it had the followingmembership:Robert M. Grow, Chai
29、rRichard H. Hulett, Vice ChairSteve M. Mills, Past ChairJudith Gorman, Secretary*Member EmeritusAlso included are the following nonvoting IEEE-SA Standards Board liaisons:Howard L. Wolfman, TAB RepresentativeMichael Janezic, NIST RepresentativeSatish K. Aggarwal, NRC RepresentativeMichelle TurnerIEE
30、E Standards Program Manager, Document DevelopmentKathryn CushIEEE Standards Program Manager, Technical Program DevelopmentThomas Alexander Richard Alfvin Butch Anton Khin Mi Mi Aung Tomo Bogataj Edward Carley Juan Carreon Keith Chow Charles Cook Wael Diab Russell Dietz Thomas Dineen Donald Eastlake,
31、 III C. FitzgeraldYukihiro Fujimoto Ilango Ganga Reinhard Gloger Ron Greenthaler Randall Groves C. GuyRainer Hach Stephen Haddock David Hunter C. Huntley Atsushi Ito Tony Jeffree Shinkyo Kaku Stuart J. Kerry Yongbum Kim Bruce Kraemer Li LiWilliam Lumpkins Elvis Maculuba Mark Maloney Arthur Marris Pe
32、ter Martini Gary Michel Jose Morales Joseph Moran Eric Multanen Michael S. Newman Nick S. A. Nikjoo Satoshi Obara Stephen Palm Glenn Parsons Hayim Porat Robert Robinson Jessy V. Rouyer Randall Safier John Santhoff John Sauer Bartien Sayogo Michael Seaman Gil Shultz Amjad Soomro Matthew Squire Manika
33、ntan Srinivasan Kevin B. Stanton Thomas Starai Walter Struppler Joseph Tardo William Taylor Michael Johas Teener Patricia Thaler Mark-Rene Uchida Dmitri Varsanofiev Prabodh Varshney Menzo Wentink Kunpeng Wu Oren Yuen Zhen Zhou John BarrKaren BartlesonVictor BermanTed BurseRichard DeBlasioAndy DrozdM
34、ark EpsteinAlexander GelmanJim HughesYoung Kyun KimJoseph L. Koepfinger*John KulickDavid J. LawTed OlsenGlenn ParsonsRonald C. PetersenNarayanan RamachandranJon Walter RosdahlSam Sciacca Copyright 2010 IEEE. All rights reserved. ixContents1. Overview . 21.1 Scope . 22. References . 33. Definitions 5
35、4. Abbreviations 75. Conformance . 95.4.3 VLAN-aware Bridge requirements for congestion notification . 95.10 End station requirements for congestion notification . 96. Support of the MAC Service in VLANs . 116.10.1 Data indications 118. Principles of bridge operation . 138.6.6 Queuing frames . 1312.
36、 Bridge management 1512.1.1 Configuration management . 1512.2 Managed objects . 1512.17 Congestion notification managed objects . 1512.17.1 CN component managed object 1512.17.2 CN component priority managed object . 1612.17.3 CN Port priority managed object 1712.17.4 Congestion Point managed object
37、 . 1812.17.5 Reaction Point port priority managed object 1812.17.6 Reaction Point group managed object 1917. MIB Modules 2117.1 The Internet Standard Management Framework 2117.2 Structure of the MIB . 2117.2.16 Structure of the Congestion Notification MIB . 2117.3 Relationship to other MIB modules 2
38、317.3.16 Relationship of the Congestion Notification MIB to other MIB modules . 2317.4 Security considerations . 2417.4.16 Security considerations of the Congestion Notification MIB . 2417.7 MIB modules 2517.7.16 Congestion Notification MIB module 2530. Principles of congestion notification 6330.1 C
39、ongestion notification design requirements . 6330.2 Quantized Congestion Notification protocol 6630.2.1 The CP Algorithm . 6630.2.2 Basic Reaction Point algorithm 6730.2.3 RP algorithm with timer . 6830.3 Congestion Controlled Flow .69x Copyright 2010 IEEE. All rights reserved.30.4 Congestion Notifi
40、cation Priority Value 7030.5 Congestion Notification Tag . 7030.6 Congestion Notification Domain 7030.7 Multicast data 7130.8 Congestion notification and additional tags 7131. Congestion notification entity operation . 7331.1 Congestion aware Bridge Forwarding Process . 7331.1.1 Congestion Point . 7
41、331.1.2 Congestion Point ingress multiplexer . 7431.2 Congestion aware end station functions . 7431.2.1 Output flow segregation 7531.2.2 Per-CNPV station function . 7631.2.3 Flow Select Database 7831.2.4 Flow multiplexer . 7831.2.5 CNM demultiplexer 7831.2.6 Input flow segregation 7831.2.7 End stati
42、on input queue . 7931.2.8 Reception selection . 7932. Congestion notification protocol 8132.1 Congestion Notification Domain operations 8132.1.1 Congestion Notification Domain defense . 8132.1.2 Automatic Congestion Notification Domain recognition . 8332.1.3 Variables controlling Congestion Notifica
43、tion Domain defense 8332.2 CN component variables . 8432.2.1 cngMasterEnable 8532.2.2 cngCnmTransmitPriority 8532.2.3 cngDiscardedFrames . 8532.2.4 cngErroredPortList 8532.3 Congestion notification per-CNPV variables . 8532.3.1 cncpDefModeChoice 8532.3.2 cncpAlternatePriority 8632.3.3 cncpAutoAltPri
44、 . 8632.3.4 cncpAdminDefenseMode . 8632.3.5 cncpCreation . 8632.3.6 cncpLldpInstanceChoice . 8632.3.7 cncpLldpInstanceSelector . 8632.4 CND defense per-Port per-CNPV variables . 8732.4.1 cnpdDefModeChoice 8732.4.2 cnpdAdminDefenseMode . 8732.4.3 cnpdAutoDefenseMode 8832.4.4 cnpdLldpInstanceChoice 88
45、32.4.5 cnpdLldpInstanceSelector . 8832.4.6 cnpdAlternatePriority 8832.4.7 cnpdXmitCnpvCapable . 8832.4.8 cnpdXmitReady 8832.4.9 cncpDoesEdge 8932.4.10 cnpdAcceptsCnTag . 8932.4.11 cnpdRcvdCnpv 8932.4.12 cnpdRcvdReady 8932.4.13 cnpdIsAdminDefMode . 8932.4.14 cnpdDefenseMode 90Copyright 2010 IEEE. All
46、 rights reserved. xi32.5 Congestion Notification Domain defense procedures 9032.5.1 DisableCnpvRemapping() 9032.5.2 TurnOnCnDefenses() 9032.5.3 TurnOffCnDefenses() . 9032.6 Congestion Notification Domain defense state machine 9132.7 Congestion notification protocol 9132.8 Congestion Point variables
47、. 9232.8.1 cpMacAddress 9332.8.2 cpId . 9332.8.3 cpQSp 9332.8.4 cpQLen 9332.8.5 cpQLenOld 9332.8.6 cpW . 9332.8.7 cpQOffset 9332.8.8 cpQDelta . 9332.8.9 cpFb 9332.8.10 cpEnqued 9432.8.11 cpSampleBase . 9432.8.12 cpDiscardedFrames . 9432.8.13 cpTransmittedFrames 9432.8.14 cpTransmittedCnms 9432.8.15
48、cpMinHeaderOctets 9432.9 Congestion Point procedures 9432.9.1 Random . 9432.9.2 NewCpSampleBase() 9532.9.3 EM_UNITDATA.request (parameters) 9532.9.4 GenerateCnmPdu() . 9532.10 Reaction Point per-Port per-CNPV variables . 9732.10.1 rpppMaxRps 9732.10.2 rpppCreatedRps 9732.10.3 rpppRpCentiseconds . 97
49、32.11 Reaction Point group variables . 9732.11.1 rpgEnable 9832.11.2 rpgTimeReset 9832.11.3 rpgByteReset . 9832.11.4 rpgThreshold . 9832.11.5 rpgMaxRate 9832.11.6 rpgAiRate 9832.11.7 rpgHaiRate 9832.11.8 rpgGd 9832.11.9 rpgMinDecFac 9832.11.10 rpgMinRate . 9932.12 Reaction Point timer . 9932.12.1 RpWhile 9932.13 Reaction Point variables . 9932.13.1 rpEnabled 9932.13.2 rpByteCount 9932.13.3 rpByteStage . 9932.13.4 rpTimeStage 10032.13.5 rpTargetRate . 10032.13.6 rpCurrentRate 10032.13.7 rpFreeze 10032.13.8 rp
