SIST EN 62439-5:2010
(Main)Industrial communication networks high availability automation networks - Part 5: Beacon Redundancy Protocol (BRP) (IEC 62439-5:2010)
Industrial communication networks high availability automation networks - Part 5: Beacon Redundancy Protocol (BRP) (IEC 62439-5:2010)
The IEC 62439 series is applicable to high-availability automation networks based on the ISO/IEC 8802-3 (IEEE 802.3) (Ethernet) technology. This part of the IEC 62439 series specifies a redundancy protocol that is based on the duplication of the network, the redundancy protocol being executed within the end nodes, as opposed to a redundancy protocol built in the switches. Fast error detection is provided by two beacon nodes, the switchover decision is taken in every node individually. The crossnetwork connection capability enables single attached end nodes to be connected on either of the two networks.
Industrielle Kommunikationsnetze - Hochverfügbare Automatisierungsnetze - Teil 5: Funkbaken-Redundanz-Protokoll (BRP) (IEC 62439-5:2010)
Réseaux de communication industrielle - Réseaux d’automatisme à haute disponibilité - Partie 5 :Protocole de redondance à balise (BRP) (CEI 62439-5:2010)
La CEI 62439-5:2010 concerne les réseaux d'automatisme à haute disponibilité reposant sur la technologie (Ethernet) de l'ISO/CEI 8802-3 (IEEE 802.3). La présente partie de la série CEI 62439 porte sur un protocole de redondance reposant sur la duplication du réseau, ce protocole étant exécuté dans les noeuds d'extrémité, par opposition à un protocole de redondance intégré aux commutateurs. La détection rapide des erreurs est assurée par deux noeuds balise, la décision de basculement étant prise dans chaque noeud individuellement. La capacité de connexion inter-réseau permet à des noeuds d'extrémité à une seule association d'être connectés sur l'un ou l'autre des deux réseaux. La présente norme annule et remplace la CEI 62439 publiée en 2008. Cette première édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes:
- ajout d'une méthode de calcul pour le protocole RSTP (Rapid Spanning Tree Protocol, IEEE 802.1Q),
- ajout de deux nouveaux protocoles de redondance: HSR (redondance transparente de haute disponibilité) et DRP (protocole de redondance distribuée),
- déplacement des Articles 1 à 4 (Introduction, Définitions, Aspects généraux) et des Annexes (Taxinomie, Calcul de disponibilité) dans la CEI 62439-1, qui servent à présent de base aux autres documents,
- déplacement de l'Article 5 (MRP, Media Redundancy Protocol) dans la CEI 62439-2 avec peu de modifications éditoriales,
- déplacement de l'Article 6 (PRP, Protocole de Redondance Parallèle) dans la CEI 62439-3 avec peu de modifications éditoriales,
- déplacement de l'Article 7 (CRP, Protocole de Redondance Transréseau) dans la CEI 62439-4 avec peu de modifications éditoriales, et
- déplacement de l'Article 8 (BRP, Protocole de Redondance à Balise) dans la CEI 62439-5 avec peu de modifications éditoriales,
- ajout d'une méthode de calcul du temps de reprise maximal du protocole RSTP dans une configuration restreinte (anneau) dans la CEI 62439-1 (Article 8),
- ajout de spécifications du protocole HSR, qui partage les principes du protocole PRP dans la CEI 62439-3 (Article 5), et
- introduction du protocole DRP (CEI 62439-6).
La présente version bilingue (2012-04) correspond à la version anglaise monolingue publiée en 2010-02.
Cette publication doit être lue conjointement avec la CEI 62439-1:2010.
Industrijska komunikacijska omrežja za avtomatizacijo z visoko razpoložljivostjo - 5. del: Protokol redundance Beacon (BRP) (IEC 62439-5:2010)
Serija IEC 62439 velja za omrežja za avtomatizacijo z visoko razpoložljivostjo, osnovana na ISO/IEC 8802-3 (IEEE 802.3) (eternet) tehnologiji. Ta del serije IEC 62439 določa redundančni protokol, osnovan na podvajanju omrežja, kjer se redundančni protokol izvaja znotraj končnih vozlišč, v nasprotju z redundančnimi protokoli, vgrajenimi v stikala. Hitro zaznavanje napak je zagotovljeno z dvema vozliščema-oddajnikoma, odločitev za preklop pa se izvede na vsakem vozlišču posebej. Med-mrežna sposobnost povezave omogoča enojnim priključenim končnim vozliščem, da so lahko povezana na obeh omrežjih.
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Industrijska komunikacijska omrežja za avtomatizacijo z visoko razpoložljivostjo - 5. del: Protokol redundance Beacon (BRP) (IEC 62439-5:2010)Industrielle Kommunikationsnetze - Hochverfügbare Automatisierungsnetze - Teil 5: Funkbaken-Redundanz-Protokoll (BRP) (IEC 62439-5:2010)Réseaux de communication industrielle - Réseaux d’automatisme à haute disponibilité - Partie 5 :Protocole de redondance à balise (BRP) (CEI 62439-5:2010)Industrial communication networks high availability automation networks - Part 5: Beacon Redundancy Protocol (BRP) (IEC 62439-5:2010)35.110OmreževanjeNetworking25.040.01Sistemi za avtomatizacijo v industriji na splošnoIndustrial automation systems in generalICS:Ta slovenski standard je istoveten z:EN 62439-5:2010SIST EN 62439-5:2010en01-maj-2010SIST EN 62439-5:2010SLOVENSKI
STANDARD
SIST EN 62439-5:2010
EUROPEAN STANDARD EN 62439-5 NORME EUROPÉENNE
EUROPÄISCHE NORM March 2010
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: Avenue Marnix 17, B - 1000 Brussels
© 2010 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62439-5:2010 E
ICS 25.040; 35.040 Supersedes EN 62439:2008 (partially)
English version
Industrial communication networks -
High availability automation networks -
Part 5: Beacon Redundancy Protocol (BRP) (IEC 62439-5:2010)
Réseaux de communication industrielle - Réseaux d’automatisme à haute disponibilité -
Partie 5 :Protocole de redondance à balise (BRP)
(CEI 62439-5:2010)
Industrielle Kommunikationsnetze -
Hochverfügbare Automatisierungsnetze - Teil 5: Funkbaken-Redundanz-Protokoll (BRP)
(IEC 62439-5:2010)
This European Standard was approved by CENELEC on 2010-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
SIST EN 62439-5:2010
EN 62439-5:2010 - 2 -
Foreword The text of document 65C/583/FDIS, future edition 1 of IEC 62439-5, prepared by SC 65C, Industrial networks, of IEC TC 65, Industrial-process measurement, control and automation, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62439-5 on 2010-03-01. This EN 62439-5 together with EN 62439-1, EN 62439-2, EN 62439-3, EN 62439-4 and EN 62439-6 supersedes EN 62439:2008. EN 62439-5:2010 includes the following significant technical changes with respect to EN 62439:2008: –
adding a calculation method for RSTP (rapid spanning tree protocol, IEEE 802.1Q), –
adding two new redundancy protocols: HSR (High-availability Seamless Redundancy) and DRP (Distributed Redundancy Protocol), –
moving former Clauses 1 to 4 (introduction, definitions, general aspects) and the Annexes (taxonomy, availability calculation) to EN 62439-1, which serves now as a base for the other documents, –
moving Clause 5 (MRP) to EN 62439-2 with minor editorial changes, –
moving Clause 6 (PRP) was to EN 62439-3 with minor editorial changes, –
moving Clause 7 (CRP) was to EN 62439-4 with minor editorial changes, and –
moving Clause 8 (BRP) was to EN 62439-5 with minor editorial changes, –
adding a method to calculate the maximum recovery time of RSTP in a restricted configuration (ring) to EN 62439-1 as Clause 8, –
adding specifications of the HSR (High-availability Seamless Redundancy) protocol, which shares the principles of PRP to EN 62439-3 as Clause 5, and –
introducing the DRP protocol as EN 62439-6. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop)
2010-12-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2013-03-01 Annex ZA has been added by CENELEC. __________ SIST EN 62439-5:2010
- 3 - EN 62439-5:2010 Endorsement notice The text of the International Standard IEC 62439-5:2010 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 61158 series NOTE
Harmonized in EN 61158 series (not modified). IEC 62439-2 NOTE
Harmonized as EN 62439-2. IEC 62439-3 NOTE
Harmonized as EN 62439-3. IEC 62439-4 NOTE
Harmonized as EN 62439-4. IEC 62439-6 NOTE
Harmonized as EN 62439-6.
SIST EN 62439-5:2010
EN 62439-5:2010 - 4 -
Annex ZA
(normative)
Normative references to international publications with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
NOTE
When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.
Publication Year Title EN/HD Year
IEC 60050-191 - International Electrotechnical Vocabulary (IEV) - Chapter 191: Dependability
and quality of service - -
IEC 62439-1 2010 Industrial communication networks - High availability automation networks -
Part 1: General concepts and calculation methods EN 62439-1 2010
ISO/IEC/TR 8802-1 - Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Specific requirements -
Part 1: Overview of Local Area Network Standards - -
ISO/IEC 8802-3 2000 Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Specific requirements -
Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications - -
IEEE 802.1D - IEEE Standard for Local and Metropoitan Area Networks - Media Access Control (MAC) Bridges - -
IEEE 802.1Q - IEEE Standard for Local and Metropolitan Area Networks - Virtual Bridged Local Area Networks - -
SIST EN 62439-5:2010
IEC 62439-5Edition 1.0 2010-02INTERNATIONAL STANDARD
Industrial communication networks – High availability automation networks –
Part 5: Beacon Redundancy Protocol (BRP)
INTERNATIONAL ELECTROTECHNICAL COMMISSION XICS 25.040, 35.040
PRICE CODEISBN 2-8318-1081-5
® Registered trademark of the International Electrotechnical Commission ® SIST EN 62439-5:2010 colourinside
– 2 – 62439-5 © IEC:2010(E) CONTENTS FOREWORD.4 INTRODUCTION.6 1 Scope.7 2 Normative references.7 3 Terms, definitions, abbreviations, acronyms, and conventions.7 3.1 Terms and definitions.7 3.2 Abbreviations and acronyms.8 3.3 Conventions.8 4 BRP overview.8 5 BRP principle of operation.8 5.1 General.8 5.2 Network topology.8 5.3 Network components.10 5.4 Rapid reconfiguration of network traffic.11 6 BRP stack and fault detection features.11 7 BRP protocol specification.13 7.1 MAC addresses.13 7.2 EtherType.13 7.3 Fault detection mechanisms.13 7.4 End node state diagram.13 7.5 Beacon end node state diagram.21 8 BRP message structure.27 8.1 General.27 8.2 ISO/IEC 8802-3 (IEEE 802.3) tagged frame header.28 8.3 Beacon message.28 8.4 Learning_Update message.28 8.5 Failure_Notify message.29 8.6 Path_Check_Request message.29 8.7 Path_Check_Response message.29 9 BRP fault recovery time.29 10 BRP service definition.30 10.1 Supported services.30 10.2 Common service parameters.31 10.3 Set_Node_Parameters service.31 10.4 Get_Node_Parameters service.33 10.5 Add_Node_Receive_Parameters service.35 10.6 Remove_Node_Receive_Parameters service.37 10.7 Get_Node_Status service.38 11 BRP Management Information Base (MIB).39 Bibliography.41
Figure 1 – BRP star network example.9 Figure 2 – BRP linear network example.9 Figure 3 – BRP ring network example.10 Figure 4 – BRP stack architecture.11 SIST EN 62439-5:2010
62439-5 © IEC:2010(E) – 3 – Figure 5 – BRP state diagram of end node.14 Figure 6 – BRP state diagram for beacon end node.21
Table 1 – BRP end node flags.16 Table 2 – BRP end node state transition table.17 Table 3 – BRP beacon end node flags.23 Table 4 – BRP beacon end node state transition table.24 Table 5 – BRP common header with ISO/IEC 8802-3 (IEEE 802.3) tagged frame format.28 Table 6 – BRP beacon message format.28 Table 7 – BRP Learning_Update message format.28 Table 8 – BRP Failure_Notify message format.29 Table 9 – BRP Path_Check_Request message format.29 Table 10 – BRP Path_Check_Response message format.29 Table 11 – BRP Set_Node_Parameters service parameters.32 Table 12 – BRP Get_Node_Parameters service parameters.34 Table 13 – BRP Add_Node_Receive_Parameters service parameters.36 Table 14 – BRP Remove_Node_Receive_Parameters service parameters.37 Table 15 – BRP Get_Node_Status service parameters.38
SIST EN 62439-5:2010
– 4 – 62439-5 © IEC:2010(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
INDUSTRIAL COMMUNICATION NETWORKS –
HIGH AVAILABILITY AUTOMATION NETWORKS –
Part 5: Beacon Redundancy Protocol (BRP)
FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. International Standard IEC 62439-5 has been prepared by subcommittee 65C: Industrial Networks, of IEC technical committee 65: Industrial-process measurement, control and automation. This standard cancels and replaces IEC 62439 published in 2008. This first edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 62439 (2008): – adding a calculation method for RSTP (rapid spanning tree protocol, IEEE 802.1Q),
– adding two new redundancy protocols: HSR (High-availability Seamless Redundancy) and DRP (Distributed Redundancy Protocol),
– moving former Clauses 1 to 4 (introduction, definitions, general aspects) and the Annexes (taxonomy, availability calculation) to IEC 62439-1, which serves now as a base for the other documents,
– moving Clause 5 (MRP) to IEC 62439-2 with minor editorial changes, SIST EN 62439-5:2010
62439-5 © IEC:2010(E) – 5 – – moving Clause 6 (PRP) was to IEC 62439-3 with minor editorial changes,
– moving Clause 7 (CRP) was to IEC 62439-4 with minor editorial changes, and
– moving Clause 8 (BRP) was to IEC 62439-5 with minor editorial changes, – adding a method to calculate the maximum recovery time of RSTP in a restricted configuration (ring) to IEC 62439-1 as Clause 8,
– adding specifications of the HSR (High-availability Seamless Redundancy) protocol, which shares the principles of PRP to IEC 62439-3 as Clause 5, and
– introducing the DRP protocol as IEC 62439-6. The text of this standard is based on the following documents: FDIS Report on voting 65C/583/FDIS 65C/589/RVD
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This International Standard is to be read in conjunction with IEC 62439-1:2010, Industrial communication networks – High availability automation networks – Part 1: General concepts and calculation methods. A list of the IEC 62439 series can be found, under the general title Industrial communication networks – High availability automation networks, on the IEC website. This publication has been drafted in accordance with ISO/IEC Directives, Part 2. The committee has decided that the contents of this amendment and the base publication will remain unchanged until the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will be
• reconfirmed, • withdrawn, • replaced by a revised edition, or • amended. A bilingual version of this standard may be issued at a later date.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this publication using a colour printer.
SIST EN 62439-5:2010
– 6 – 62439-5 © IEC:2010(E) INTRODUCTION The IEC 62439 series specifies relevant principles for high availability networks that meet the requirements for industrial automation networks.
In the fault-free state of the network, the protocols of the IEC 62439 series provide ISO/IEC 8802-3 (IEEE 802.3) compatible, reliable data communication, and preserve determinism of real-time data communication. In cases of fault, removal, and insertion of a component, they provide deterministic recovery times.
These protocols retain fully the typical Ethernet communication capabilities as used in the office world, so that the software involved remains applicable. The market is in need of several network solutions, each with different performance characteristics and functional capabilities, matching diverse application requirements. These solutions support different redundancy topologies and mechanisms which are introduced in IEC 62439-1 and specified in the other Parts of the IEC 62439 series. IEC 62439-1 also distinguishes between the different solutions, giving guidance to the user. The IEC 62439 series follows the general structure and terms of IEC 61158 series. The International Electrotechnical Commission (IEC) draws attention to the fact that it is claimed that compliance with this document may involve the use of a patent concerning fault-tolerant Ethernet provided
through the use of special interfaces providing duplicate ports
that may be alternatively enabled with the same network address. Switching between the ports corrects for single faults in a two-way redundant system. This is given in Clauses 5 and 6. IEC takes no position concerning the evidence, validity and scope of this patent right. The holder of this patent right has assured the IEC that he/she is willing to negotiate licences either free of charge or under reasonable and non-discriminatory terms and conditions with applicants throughout the world.
In this respect, the statement of the holder of this patent right is registered with IEC. Information may be obtained from:
Rockwell Automation Technologies
1 Allen-Bradley Drive
Mayfield Heights
Ohio
USA Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. IEC shall not be held responsible for identifying any or all such patent rights. ISO (www.iso.org/patents) and IEC (http://www.iec.ch/tctools/patent_decl.htm) maintain on-line data bases of patents relevant to their standards. Users are encouraged to consult the data bases for the most up to date information concerning patents. SIST EN 62439-5:2010
62439-5 © IEC:2010(E) – 7 – INDUSTRIAL COMMUNICATION NETWORKS –
HIGH AVAILABILITY AUTOMATION NETWORKS –
Part 5: Beacon Redundancy Protocol (BRP)
1 Scope The IEC 62439 series is applicable to high-availability automation networks based on the ISO/IEC 8802-3 (IEEE 802.3) (Ethernet) technology. This part of the IEC 62439 series specifies a redundancy protocol that is based on the duplication of the network, the redundancy protocol being executed within the end nodes, as opposed to a redundancy protocol built in the switches. Fast error detection is provided by two beacon nodes, the switchover decision is taken in every node individually. The cross-network connection capability enables single attached end nodes to be connected on either of the two networks.
2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-191, International Electrotechnical Vocabulary – Chapter 191: Dependability and quality of service IEC 62439-1:2010, Industrial communication networks – High availability automation networks – Part 1: General concepts and calculation methods ISO/IEC/TR 8802-1, Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – Specific requirements – Part 1: Overview of Local Area Network Standards (IEEE 802.1) ISO/IEC 8802-3:2000, Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – Specific requirements – Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications IEEE 802.1D, IEEE standard for local Local and metropolitan area networks Media Access Control (MAC) Bridges IEEE 802.1Q, IEEE standards for local and metropolitan area network. Virtual bridged local area networks 3 Terms, definitions, abbreviations, acronyms, and conventions 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60050-191, as well as in IEC 62439-1, apply. SIST EN 62439-5:2010
– 8 – 62439-5 © IEC:2010(E) 3.2 Abbreviations and acronyms For the purposes of this document, the abbreviations and acronyms given in IEC 62439-1, apply, in addition to the following: BRP Beacon Redundancy Protocol DANB Double attached node implementing BRP 3.3 Conventions This part of the IEC 62439 series follows the conventions defined in IEC 62439-1. 4 BRP overview This clause specifies a protocol for an Ethernet network tolerant to all single point failures. This protocol is called Beacon Redundancy Protocol or BRP. A network based on the BRP is called a BRP network. The BRP network is based on switched ISO/IEC 8802-3 (IEEE 802.3) (Ethernet) and ISO/IEC/TR 8802-1 (IEEE 802.1) technologies and redundant infrastructure. In this network, the decision to switch between infrastructures is made individually in each end node. 5 BRP principle of operation 5.1 General Subclauses
5.2 to
5.4 are an explanation of overall actions performed by the BRP state machine. If a difference in the interpretation occurs between these subclauses and the state machines in
7, then the state machines take precedence. 5.2 Network topology The BRP network topology can be described as two interconnected top switches, each heading an underlying topology of star, line, or ring. Beacon end nodes shall be connected to the top switches. Examples of star, linear and ring BRP networks are shown in Figure 1, Figure 2 and Figure 3 respectively. SIST EN 62439-5:2010
62439-5 © IEC:2010(E) – 9 – endnodeendnodeendnodeendnodeendnodeendnodebeaconnodebeaconnodeendnodeendnodeendnodeswitchswitchswitchswitchswitchswitchswitchswitchleaflinkleaflinkleaflinkinterswitchlinkinterswitchlinkedgeportsedgeportsaggregated linksinterswitchlportnetworkinfrastructure Anetworkinfrastructure Bendnodeendnodeendnodeendnodeendnodeendnodeendnodenodeend
Figure 1 – BRP star network example endnodeendnodeendnodeendnodeendnodeendnodeendnodeendnodebeaconnodebeaconnodeendnodeendnodeendnodeswitchswitchleaf linkleaf linkinterswitchlinkinterswitchlinkedgeportsedgeportsinterswitchportinterswitchportswitchswitchswitchswitchswitchswitch Figure 2 – BRP linear network example IEC
385/10 IEC
386/10 SIST EN 62439-5:2010
– 10 – 62439-5 © IEC:2010(E)
endnodeendnodeendnodeendnodeendnodeendnodeendnodeendnodebeaconnodebeaconnodeendnodeendnodeendnodeswitchswitchleaf linkleaf linkinterswitchlinkinterswitchlinkedgeportsedgeportsinterswitchportinterswitchportswitchswitchswitchswitchswitchswitch Figure 3 – BRP ring network example 5.3 Network components The BRP network is built from layer 2 switches compliant with IEEE 802.1D and ISO/IEC 8802-3 (IEEE 802.3). No support of the BRP protocol in switches is required.
Figure 1 shows an example of a BRP star network in the 2-way redundancy mode. It uses two sets of network infrastructure A and B (shown in two different colours). The number of levels of switches and number of switches on each level are dependent only on application requirements. Even with three levels of hierarchy it is possible to construct very large networks. For example, a BRP star network built from switches with eight regular ports and one uplink port can contain 500 nodes maximum. Two switches at the top level shall be connected to each other with one or more links providing sufficient bandwidth. With link aggregation capability, traffic is shared among bundle of links and failure of one link does not bring the network down. With such an arrangement infrastructures A and B form a single network. Two types of end nodes can be connected to the BRP network: doubly attached and singly attached. A doubly attached end node can function as a BRP end node or a BRP beacon end node. A BRP beacon end node is a special case of a doubly attached end node that is connected directly to the top switches. Though doubly attached BRP end nodes have two network ports they use only one MAC address. At any given point in time a BRP end node actively communicates through only one of its ports, while blocking all transmit and receive traffic on its other port, with the exception of received beacon messages and Failure_Notify messages. Fault tolerance is achieved in a
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