IEC 62439-2:2016

Industrial communication networks - High availability automation networks - Part 2: Media Redundancy Protocol (MRP)

IEC 62439-2:2016 is applicable to high-availability automation networks based on the ISO/IEC/IEEE 8802-3 (IEEE 802.3) (Ethernet) technology. This part of the IEC 62439 series specifies a recovery protocol based on a ring topology, designed to react deterministically on a single failure of an inter-switch link or switch in the network, under the control of a dedicated media redundancy manager node.This second edition cancels and replaces the first edition published in 2010. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- adding a protocol extension to select the media redundancy manager automatically;
- adding a protocol to redundantly connect media redundancy protocol rings.
This publication is to be read in conjunction with IEC 62439-1:2010.

Réseaux de communication industriels - Réseaux d'automatisme à haute disponibilité - Partie 2: Protocole de redondance du support (MRP)

IEC 62439-2:2016 concerne les réseaux de haute disponibilité pour l'automation reposant sur la technologie ISO/IEC/IEEE 8802-3 (IEEE 802.3) (Ethernet). La présente partie de la série IEC 62439 spécifie un protocole de reprise reposant sur une topologie en anneau, conçu pour réagir de manière déterministe sur une seule défaillance d'une maille interétage ou d'un commutateur du réseau, sous le contrôle d'un n ud du gestionnaire de redondance du support dédié. Cette deuxième édition annule et remplace la première édition parue en 2010. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- ajout d'une extension de protocole pour sélectionner automatiquement le gestionnaire de redondance du support;
- ajout d'un protocole pour connecter de manière redondante les anneaux du protocole de redondance du support.
Cette publication doit être lue conjointement avec la IEC 62439-1:2010.

General Information

• Status: Published
• Publication Date: 29-Mar-2016
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100.05 - Multilayer applications
• Technical Committee: SC 65C - Industrial networks
• Drafting Committee: WG 15 - TC 65/SC 65C/WG 15
• Current Stage: DELPUB - Deleted Publication
• Start Date: 15-Dec-2021
• Completion Date: 26-Oct-2025

Relations

• Revises: IEC 62439-2:2010 - Industrial communication networks - High availability automation networks - Part 2: Media Redundancy Protocol (MRP)
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62439-2 ®
Edition 2.0 2016-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – High availability automation networks –
Part 2: Media Redundancy Protocol (MRP)

Réseaux de communication industriels – Réseaux d'automatisme à haute
disponibilité –
Partie 2: Protocole de redondance du support (MRP)

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IEC 62439-2 ®
Edition 2.0 2016-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – High availability automation networks –

Part 2: Media Redundancy Protocol (MRP)

Réseaux de communication industriels – Réseaux d'automatisme à haute

disponibilité –
Partie 2: Protocole de redondance du support (MRP)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040, 35.040 ISBN 978-2-8322-3149-4

– 2 – IEC 62439-2:2016  IEC 2016
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 11
2 Normative references. 11
3 Terms, definitions, abbreviations, acronyms, and conventions . 12
3.1 Terms and definitions . 12
3.2 Abbreviations and acronyms . 12
3.3 Conventions . 12
4 MRP Overview . 12
5 MRP Media redundancy behavior . 16
5.1 General . 16
5.2 Ring ports . 16
5.3 Media Redundancy Manager (MRM) . 17
5.4 Media Redundancy Client (MRC) . 19
5.5 Redundancy domain . 19
5.6 Media Link Check . 19
5.7 Application of the Continuity Check protocol . 19
5.7.1 General . 19
5.7.2 Continuity Check Message Interval . 20
5.7.3 Maintenance Domain Level . 20
5.7.4 Maintenance Association ID (MAID) . 20
5.7.5 Maintenance Association End Point ID (MEPID) . 20
5.7.6 Sender ID TLV . 20
5.7.7 Port Status TLV . 21
5.7.8 Interface Status TLV . 21
5.8 Usage with diagnosis and alarms . 21
5.9 Ring diagnosis . 21
5.10 Multiple MRM in a single ring: Manager voting option . 21
5.10.1 General . 21
5.10.2 Basic principle of the manager voting process . 22
5.10.3 The manager voting process . 23
5.11 BLOCKED not supported (Option). 25
5.12 Interconnection port . 25
5.13 Media redundancy Interconnection Manager (MIM) . 26
5.14 Media redundancy Interconnection Client (MIC) . 29
5.15 Interconnection domain . 29
5.16 Interconnection diagnosis . 30
6 MRP Class specification . 30
6.1 General . 30
6.2 Template. 30
6.2.1 Media redundancy template . 30
6.2.2 Media redundancy Interconnection template . 31
6.3 Attributes . 32
7 MRP Service specification . 36
7.1 Start MRM . 36

7.2 Stop MRM . 38
7.3 State Change . 38
7.4 Start MRC . 39
7.5 Stop MRC . 41
7.6 Read MRM . 41
7.7 Read MRC . 43
7.8 Start MIM . 45
7.9 Stop MIM . 46
7.10 Interconnection State Change. 47
7.11 Start MIC . 48
7.12 Stop MIC. 49
7.13 Read MIM . 50
7.14 Read MIC . 52
8 MRP protocol specification . 54
8.1 PDU description . 54
8.1.1 Basic data types . 54
8.1.2 DLPDU abstract syntax reference . 54
8.1.3 Coding of the DLPDU field SourceAddress . 54
8.1.4 Coding of the DLPDU field DestinationAddress . 55
8.1.5 Coding of the field TagControlInformation . 55
8.1.6 Coding of the field LT . 56
8.1.7 MRP APDU abstract syntax . 56
8.1.8 Coding of the field MRP_TLVHeader . 57
8.1.9 Coding of the field MRP_SubTLVHeader . 58
8.1.10 Coding of the field MRP_Ed1Type and MRP_Ed1ManufacturerData . 58
8.1.11 Coding of the field MRP_Version . 59
8.1.12 Coding of the field MRP_SequenceID . 59
8.1.13 Coding of the field MRP_SA . 59
8.1.14 Coding of the field MRP_OtherMRMSA . 59
8.1.15 Coding of the field MRP_Prio . 60
8.1.16 Coding of the field MRP_OtherMRMPrio . 60
8.1.17 Coding of the field MRP_PortRole . 60
8.1.18 Coding of the field MRP_RingState . 60
8.1.19 Coding of the field MRP_Interval . 61
8.1.20 Coding of the field MRP_Transition . 61
8.1.21 Coding of the field MRP_TimeStamp . 61
8.1.22 Coding of the field MRP_Blocked . 61
8.1.23 Coding of the field MRP_ManufacturerOUI . 62
8.1.24 Coding of the field MRP_IECOUI . 62
8.1.25 Coding of the field MRP_ManufacturerData . 62
8.1.26 Coding of the field MRP_DomainUUID . 62
8.1.27 Coding of the field MRP_InState . 62
8.1.28 Coding of the field MRP_InID . 63
8.2 Protocol machines . 63
8.2.1 MRM protocol machine . 63
8.2.2 MRC protocol machine . 74
8.2.3 MRA protocol machine . 80
8.2.4 MRA, MRM and MRC functions . 100
8.2.5 FDB clear timer . 105

– 4 – IEC 62439-2:2016  IEC 2016
8.2.6 Topology change timer . 105
8.2.7 MIM protocol machine . 106
8.2.8 MIC protocol machine . 115
8.2.9 MIM and MIC functions . 123
8.2.10 Interconnection Topology Change timer . 127
8.2.11 Interconnection Link Status Poll timer . 127
9 MRP installation, configuration and repair . 128
9.1 Ring port and Interconnection port parameters . 128
9.2 Ring topology parameters . 128
9.3 MRM parameters . 128
9.4 MRC parameters and constraints . 129
9.5 MRA compatibility to earlier Automanager protocol version . 129
9.6 Interconnection topology parameters . 130
9.7 MIM parameters . 130
9.8 MIC parameters and constraints . 130
9.9 Calculation of MRP ring recovery time . 131
9.9.1 Overview . 131
9.9.2 Deduction of formula . 131
9.9.3 Worst case calculation for recovery time of 10 ms . 133
9.9.4 Worst case calculation for 50 devices . 134
9.10 Calculation of MRP Automanager voting time . 134
10 MRP Management Information Base (MIB) . 134
10.1 General . 134
10.2 MRP MIB with a monitoring view . 134
10.3 MRP MIB with a management and monitoring view . 147
Annex A (normative) Optional earlier version of the Automanager protocol . 162
Bibliography . 163

Figure 1 – Two MRP rings redundantly connected via MRP Interconnection . 14
Figure 2 – MRP stack . 16
Figure 3 – MRP ring topology with one manager and clients . 17
Figure 4 – MRP open ring with MRM . 18
Figure 5 – MRP ring with MRA at network startup . 22
Figure 6 – MRP ring after the manager voting process . 22
Figure 7 – Manager voting process . 24
Figure 8 – MRA located outside the MRP ring . 25
Figure 9 – MRP Interconnection topology . 27
Figure 10 – MRP ring interconnection open . 28
Figure 11 – MRP protocol machine for MRM . 63
Figure 12 – MRP protocol machine for MRC . 74
Figure 13 – MRP protocol machine for MRA . 81
Figure 14 – MRP protocol machine for MIM in RC-mode and LC-mode . 107
Figure 15 – MRP protocol machine for MIC in RC-mode and LC-mode . 116

Table 1 – Patent information . 9
Table 2 – Coding of the Maintenance Association ID (MAID) . 20

Table 3 – MRP Start MRM . 36
Table 4 – MRP Stop MRM . 38
Table 5 – MRP Change State . 39
Table 6 – MRP Start MRC . 40
Table 7 – MRP Stop MRC . 41
Table 8 – MRP Read MRM . 42
Table 9 – MRP Read MRC . 44
Table 10 – MRP Start MIM . 45
Table 11 – MRP Stop MIM . 47
Table 12 – MRP Interconnection Change State . 47
Table 13 – MRP Start MIC . 48
Table 14 – MRP Stop MIC . 50
Table 15 – MRP Read MIM . 51
Table 16 – MRP Read MIC . 53
Table 17 – MRP DLPDU syntax for ISO/IEC/IEEE 8802-3 (IEEE 802.3) . 54
Table 18 – MRP OUI . 55
Table 19 – MRP MulticastMACAddress . 55
Table 20 – MRP TagControlInformation.Priority field . 56
Table 21 – MRP LT field . 56
Table 22 – MRP APDU syntax . 56
Table 23 – MRP Substitutions . 57
Table 24 – MRP_TLVHeader.Type . 58
Table 25 – MRP_SubTLVHeader.Type . 58
Table 26 – MRP_Ed1Type and MRP_Ed1ManufacturerData . 59
Table 27 – MRP_Ed1Type and MRP_Ed1ManufacturerData . 59
Table 28 – MRP_Version . 59
Table 29 – Coding of the field MRP_OtherMRMSA . 60
Table 30 – MRP_Prio . 60
Table 31 – Coding of the field MRP_OtherMRMPrio . 60
Table 32 – MRP_PortRole . 60
Table 33 – MRP_RingState . 61
Table 34 – MRP_Interval . 61
Table 35 – MRP_Transition . 61
Table 36 – MRP_TimeStamp . 61
Table 37 – MRP_Blocked . 62
Table 38 – MRP_DomainUUID . 62
Table 39 – MRP_InState . 62
Table 40 – MRP Local variables of MRM protocol machine . 65
Table 41 – MRM State machine . 66
Table 42 – MRP Local variables of MRC protocol machine. 75
Table 43 – MRC state machine . 76
Table 44 – MRP local variables of MRA protocol machine . 82
Table 45 – MRA state machine . 83

– 6 – IEC 62439-2:2016  IEC 2016
Table 46 – MRP functions and macros . 101
Table 47 – MRP FDB clear timer . 105
Table 48 – MRP topology change timer . 106
Table 49 – MRP Local variables of MIM protocol machine . 108
Table 50 – MIM State machine for LC-mode . 109
Table 51 – MIM State machine for RC-mode . 112
Table 52 – MRP Local variables of MIC protocol machine . 117
Table 53 – MIC State machine for LC-mode . 118
Table 54 – MIC State machine for RC-mode . 121
Table 55 – MRP Interconnection functions . 124
Table 56 – MRP Interconnection topology change timer . 127
Table 57 – MRP Interconnection link status poll timer . 128
Table 58 – MRP Network/Connection parameters . 128
Table 59 – MRP MRM parameters . 129
Table 60 – MRP MRC parameters . 129
Table 61 – MRP MIM parameters . 130
Table 62 – MRP MIC parameters . 131
Table A.1 – Compatible mode MRP_Option for MRP_Test Substitutions . 162
Table A.2 – Compatible mode MRP_Option frames MRP_TestMgrNAck and
MRP_TestPropagate Substitutions . 162

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
HIGH AVAILABILITY AUTOMATION NETWORKS –

Part 2: Media Redundancy Protocol (MRP)

FOREWORD
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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 62439-2 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This second edition cancels and replaces the first edition published in 2010. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– adding a protocol extension to select the media redundancy manager automatically;
– adding a protocol to redundantly connect media redundancy protocol rings.

– 8 – IEC 62439-2:2016  IEC 2016
The text of this standard is based on the following documents:
FDIS Report on voting
65C/834/FDIS 65C/841/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 publication has been drafted in accordance with ISO/IEC Directives, Part 2.
This International Standard is to be read in conjunction with IEC 62439-1.
A list of all parts of the IEC 62439 series, published under the general title Industrial
communication networks – High availability automation networks, can be found on the IEC
website.
The committee has decided that the contents of this 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.
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 document using a
colour printer.
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/IEEE 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 the 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 ring
protocol given in Clause 5. Table 1 gives an overview of the relevant patents.
Table 1 – Patent information
No. Status Country Granted Patent Number Title
or
Application Number (if
pending)
1 granted US US 6430151 Local networking with redundancy properties
having a redundancy manager
granted CA CA 2323429
granted CN CN 117195
granted NO NO 330908
granted EP (AT, BE, CH, EP 1062787
DE, DK, ES, FR,
GB, IT, NL, SE)
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:
Siemens Aktiengesellschaft
Otto-Hahn-Ring 6
Munich 81739
Germany
and
Hirschmann Automation and Control GmbH
Stuttgarter Strasse 45-51
– 10 – IEC 62439-2:2016  IEC 2016
Neckartenzlingen 72654
Germany
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://patents.iec.ch/) 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.

INDUSTRIAL COMMUNICATION NETWORKS –
HIGH AVAILABILITY AUTOMATION NETWORKS –

Part 2: Media Redundancy Protocol (MRP)

1 Scope
The IEC 62439 series is applicable to high-availability automation networks based on the
ISO/IEC/IEEE 8802-3 (IEEE 802.3) (Ethernet) technology.
This part of the IEC 62439 series specifies a recovery protocol based on a ring topology,
designed to react deterministically on a single failure of an inter-switch link or switch in the
network, under the control of a dedicated media redundancy manager node.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. 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 61158-6-10:2014, Industrial communication networks – Fieldbus specifications –
Part 6-10: Application layer protocol specification – Type 10 elements
IEC 61784-1, Industrial communication networks – Profiles – Part 1: Fieldbus profiles
IEC 61784-2, Industrial communication networks – Profiles – Part 2: Additional fieldbus
profiles for real-time networks based on ISO/IEC 8802-3
IEC 62439-1:2010, Industrial communication networks – High availability automation networks
– Part 1: General concepts and calculation methods
IEC 62439-1:2010/AMD1:2012
ISO/IEC 10164-1, Information technology – Open Systems Interconnection – Systems
Management: Object Management Function
ISO/IEC/IEEE 8802-3 Standard for Ethernet
IEEE 802.1D:2004, IEEE Standard for Local and metropolitan area networks – Media Access
Control (MAC) Bridges
IEEE 802.1Q:2011, IEEE Standard for Local and metropolitan area networks – Media Access
Control (MAC) Bridges and Virtual Bridge Local Area Network
___________
A consolidated version of this publication exists, comprising IEC 62439-1:2010 and
IEC 62439-1:2010/AMD1:2012.
– 12 – IEC 62439-2:2016  IEC 2016
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, as well as the following, apply.
3.1.1
interconnection port
port of a switch that is used to interconnect two ring topologies
3.1.2
interconnection topology
topology in which two ring topologies are connected
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.
ASE Application Service Element
CCM Continuity Check Messages
CFM Connectivity Fault Management
CFM-MRP Connectivity Fault Management for MRP
CPU Central Processing Unit
FDB Filtering Database
LC-mode Link Check mode
LSB Least Significant Bit
MAID Maintenance Association ID
MD Maintenance Domain
MD Level Maintenance Domain Level
MEP Maintenance End Point
MEPID Maintenance Association End Point ID
MIB Management Information Base
MRA Media Redundancy Automanager
MRC Media Redundancy Client
MRM Media Redundancy Manager
MRP Media Redundancy Protocol
MIC Media Redundancy Interconnection Client
MIM Media Redundancy Interconnection Manager
RC-mode Ring Check mode
3.3 Conventions
This document follows the conventions defined in IEC 62439-1.
4 MRP Overview
This document specifies the Media Redundancy Protocol (MRP), a recovery protocol based
on a ring topology, and the redundant interconnection of MRP rings via the Media
Redundancy Interconnection Protocol as shown in Figure 1.

MRP is designed to react deterministically on a single failure of an inter-switch link or switch
in the ring or interconnection topology.
MRP is based on functions of ISO/IEC/IEEE 8802-3 (IEEE 802.3) and IEEE 802.1Q including
the Filtering Database (FDB) and is located between the Data Link Layer and Application
Layer (see Figure 2).
NOTE Layering is assumed to be according to IEC 61158-1.
A MRP compliant network shall have a ring topology with multiple nodes.
One of the nodes has the role of a Media Redundancy Manager (MRM). The function of the
MRM is to observe and to control the ring topology in order to react on network faults. The
MRM does this by sending frames on one ring port over the ring and receiving them from the
ring over its other ring port, and vice–versa in the other direction.
The other nodes in the ring have the role of Media Redundancy Clients (MRC). An MRC
reacts on received reconfiguration frames from the MRM and can detect and signal link
changes on its ring ports.
Certain nodes or all nodes in the ring may also start as a Media Redundancy Automanager
(MRA). MRAs select one MRM among each other by using a voting protocol. The remaining
MRAs transition to the role MRC.
Each node in the ring is able to detect the failure or recovery of an inter-switch link or the
failure or recovery of a neighboring node.
To redundantly connect two MRP rings, two nodes of each ring are assigned additional roles.
One of the nodes has the role of a media redundancy interconnection manager (MIM), in
addition to the role of a MRC or MRM. The function of the MIM is to observe and to control the
redundant interconnection topology in order to react on interconnection faults. To cover a
maximum of applications, two detection methods are provided by this international standard.
The MIM can observe the interconnection topology by either reacting directly on
interconnection port link change notification messages (LC-mode) or by sending test frames
on the interconnection port over the connected ri
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