IEC 62439-5:2016

IEC 62439-5 ®
Edition 2.0 2016-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – High availability automation networks –
Part 5: Beacon Redundancy Protocol (BRP)

Réseaux de communication industriels – Réseaux d'automatisme à haute
disponibilité –
Partie 5: Protocole de redondance à balise (BRP)

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IEC 62439-5 ®
Edition 2.0 2016-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – High availability automation networks –

Part 5: Beacon Redundancy Protocol (BRP)

Réseaux de communication industriels – Réseaux d'automatisme à haute

disponibilité –
Partie 5: Protocole de redondance à balise (BRP)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040; 35.040 ISBN 978-2-8322-3148-7

– 2 – IEC 62439-5:2016  IEC 2016

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 . 11
5.4 Rapid reconfiguration of network traffic . 12
6 BRP stack and fault detection features . 12
7 BRP protocol specification . 14
7.1 MAC addresses . 14
7.2 EtherType . 14
7.3 Fault detection mechanisms . 14
7.4 BRP end device . 14
7.4.1 State diagram . 14
7.4.2 Start-up . 15
7.4.3 Normal operation . 15
7.4.4 Fault detection . 16
7.4.5 State-Event-Action table . 16
7.5 Beacon device . 26
7.5.1 State diagram . 26
7.5.2 Start-up . 27
7.5.3 Normal operation . 27
7.5.4 Fault detection . 28
7.5.5 Changing BRP parameters . 28
7.5.6 State-Event-Action table . 29
8 BRP message structure . 36
8.1 General . 36
8.2 ISO/IEC/IEEE 8802-3 (IEEE 802.3) Tagged common message header . 36
8.3 Beacon message . 37
8.4 Path_Check_Request message . 37
8.5 Path_Check_Response message . 38
8.6 Learning_Update message . 38
9 BRP fault recovery time . 38
10 BRP service definition . 39
10.1 Supported services . 39
10.2 Common service parameters . 39
10.3 Set_Node_Parameters service . 40
10.4 Get_Node_Parameters service . 41

10.5 Get_Node_Status service . 43

11 BRP Management Information Base (MIB) . 44

Bibliography . 47

Figure 1 – BRP star network example . 9

Figure 2 – BRP linear network example . 10

Figure 3 – BRP ring network example . 11

Figure 4 – BRP stack architecture . 12

Figure 5 – State diagram for end device . 15

Figure 6 – State diagram for beacon device . 27

Table 1 – Parameter values for end device . 17
Table 2 – State-Event-Action table for end device . 18
Table 3 – Parameter values for beacon device . 29
Table 4 – State-Event-Action table for beacon device . 30
Table 5 – Destination MAC addresses . 36
Table 6 – Common message header . 37
Table 7 – Beacon message format . 37
Table 8 – Path_Check_Request message format . 37
Table 9 – Path_Check_Response message format . 38
Table 10 – Learning_Update message format . 38
Table 11 – BRP Set_Node_Parameters service parameters . 40
Table 12 – BRP Get_Node_Parameters service parameters . 42
Table 13 – BRP Get_Node_Status service parameters . 43

– 4 – IEC 62439-5:2016  IEC 2016

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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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
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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 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:
a) The protocol is now independent of application (Path_Check_Request is sent periodically);
b) Failure_Notify message has been removed;
c) Frame format had been changed;
d) New MAC address had been added.

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 the 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 publication using a
colour printer.
– 6 – IEC 62439-5:2016  IEC 2016

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 patents 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 single faults in a two-way redundant system. This is given in Clauses 5 and 6.
These patents are listed in the table below, where the [xx] notation indicates the holder of the
patent rights:
US 7,817,538 B2 [RA] Fault-tolerant Ethernet network
US 8,493,840 [RA] Fault-tolerant Ethernet network
IEC takes no position concerning the evidence, validity and scope of these patent rights.
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:
[RA] Rockwell Automation Technologies, Inc.

1 Allen-Bradley Drive
Mayfield Heights
Ohio 44124, 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://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 5: Beacon Redundancy Protocol (BRP)

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 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 singly attached end nodes to be connected on either of
the two networks.
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 62439-1, 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
ISO/IEC/IEEE 8802-3:2014, Standard for Ethernet

ISO/IEC 10164-1, Information technology – Open Systems Interconnection – Systems
Management: Object Management Function
IEEE 802.1D, IEEE Standard for Local and metropolitan area networks: Media Access Control
(MAC) Bridges
IEEE 802.1Q, IEEE Standard for Local and metropolitan area networks: Media Access Control
(MAC) Bridges and 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.
– 8 – IEC 62439-5:2016  IEC 2016

3.2 Abbreviations and acronyms

For the purposes of this document, the abbreviations and acronyms given in IEC 62439-1, as

well as the following apply:
BRP Beacon Redundancy Protocol

DANB doubly 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 part of the IEC 62439 series 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/IEEE 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 Clause 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.

aggregated links
switch
switch
network network
infrastructure A infrastructure B

interswitch
beacon
switch beacon
switch
node lport
node
edge
ports
interswitch
end end
link end
interswitch
node node
endend
node
link
nodenode
switch
switch switch switch
edge
ports
leaf
end
link
node
leaf
link
leaf
link
end endendend endend end end endend end
node nodenodenode nodenode node node nodenode node

IEC
Figure 1 – BRP star network example

– 10 – IEC 62439-5:2016  IEC 2016

interswitch link interswitch link

switch
switch
interswitch
interswitch
port port
beacon
beacon
node
node
leaf link leaf link
end
node
end end
node node
edge
edge
ports
ports
end end
end end
node node node node
end end end end
node node node node
IEC
Figure 2 – BRP linear network example

switch switch
switch
switch
switch switch
interswitch link interswitch link
switch
switch
interswitch interswitch
port port
beacon
beacon
node
node
leaf link leaf link
end
node
end
end
node
node
edge edge
ports ports
end end
end end
node node
node node
end end end end
node node node node
IEC
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/IEEE 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.
As shown in Figure 1, Figure 2 and Figure 3, two beacon end nodes shall be connected to top
level switches. Beacon end nodes multi/broadcast a short beacon message on the network
switch
switch switch
switch switch
switch
– 12 – IEC 62439-5:2016  IEC 2016

periodically. Similarly to BRP end nodes, a beacon end node at any given point in time

actively communicates through only one of its ports, while blocking all traffic on its other port.

Fault tolerance is achieved by beacon end nodes switching between their ports from inactive

to active mode and vice versa.

Singly attached end nodes may also be connected to BRP network but they do not support the

BRP protocol. A singly attached node can communicate with doubly attached nodes as well as

other singly attached nodes on the network.

Since switches are IEEE 802.1D compliant, they support the RSTP protocol. This eliminates

loop formation in BRP ring networks like in the one shown in Figure 3.

5.4 Rapid reconfiguration of network traffic
For fast reconfiguration, multicast control features in the switches shall be disabled. The
multicast traffic is therefore treated as the broadcast traffic.
Unicast packets are affected by switches learning and filtering features. After end node port
reconfiguration, switches have invalid knowledge. A switch implementing learning shall update
its database when a packet with a learned MAC address in the source field is received on a
different port from the learned port stored in the database.
When a BRP end node switches to the inactive port, its first action is to send a short multicast
message, called Learning_Update message, through its newly enabled port. As this message
propagates through the network, switches update their MAC address database resulting in
rapid reconfiguration of the unicast traffic. This message is of no interest to other end nodes
in the network and is dropped by them.
6 BRP stack and fault detection features
Figure 4 shows the BRP stack architecture. It is applicable to both BRP and beacon end
nodes.
upper layer protocols
UDP
TCP
non-TCP/IP
stack
IP
LRE
link redundancy entity
Management
(Service)
IEEE 802.3 MAC IEEE 802.3 MAC
IEEE 802.3 PHY IEEE 802.3 PHY
Port A Port B
IEC
Figure 4 – BRP stack architecture
The BRP stack contains two identical ISO/IEC/IEEE 8802-3 (IEEE 802.3) ports, identified
here as ports A and B, connected to the network. These ports interface with the MAC sub-
layer compliant with ISO/IEC/IEEE 8802-3 (IEEE 802.3). Though there are two physical ports,
a BRP end node uses only a single MAC address.

The link redundancy entity continuously monitors the status of leaf links between both ports

and corresponding ports on the switches. When a failure of the leaf link between the end node

active port and the corresponding port on the switch is detected, the link redundancy entity

shall reconfigure end node ports, provided the inactive port was not in the fault mode as well.

After reconfiguration, all traffic flows through the newly activated port. Some messages may

be lost during the failure detection and reconfiguration process, and their recovery is

supported by upper layer protocols which also deal with messages lost due to other network
errors.
The link redundancy entity also monitors arrival of beacon messages on both ports. When a
beacon message fails to arrive at the active port for a configured timeout period, the port is

declared to be in the fault mode, and the link redundancy entity shall reconfigure end node

ports, provided the other port was not in the fault mode as well. After reconfiguration all traffic
starts flowing through the newly activated port. Failure of beacon messages to arrive at
inactive ports shall also be detected.
If one of the top switches fails, then all BRP nodes connected directly to it, or to network
infrastructure below it, switch to the other network infrastructure. If, for example, the top
switch of the LAN A fails, then all BRP nodes connected to LAN A switch over to LAN B.
If the fault occurred on a beacon end node, the network continues to operate without any
problems, since the other beacon end node is active. The rate of beacon message arrival
decreases from approximately two messages per beacon timer interval to one.
It is possible for transmit path failures to occur in the opposite direction to the flow of beacon
messages. If such a fault manifests itself in the physical layer, it is detected by end nodes or
switches adjacent to the faulty link. This results in a BRP end node reconfiguring its ports
immediately or results in traffic being blocked on the affected link. The latter event leads to
loss of beacon messages at the downstream end nodes, so that they reconfigure themselves
at expiry of the beacon timeout.
When the faulted port is restored, it shall stay idle until a switchover is initiated or the
currently active port fails. When both ports are operational, the BRP end node shall
periodically switch its message activity from one port to the other. This switchover is
controlled by the Active_Port_Swap timer.
The LRE management entity is used to select an end node type (normal or beacon), configure
protocol parameters (for example, beacon timer) and obtain the end node port status (active,
failed, idle).
All detected failures shall be reported to the LRE management entity to trigger further
diagnosis and repair. Fault diagnostics services shall be provided by LRE management entity

or other accessible entities in the network.
In a case when transmit path faults are not detectable in the physical layer, the following
mechanism is employed by the BRP link redundancy entity to detect them. The BRP end
devices shall send a Path_Check_Request message once every Path Check Request Interval
to one of the currently active beacon devices on their active port in a round robin manner. For
example, if three beacon devices are currently active, a BRP end device shall send a
Path_Check_Request message to beacon device 1 in the first interval, to beacon device 2 in
the second interval and so on. Upon receiving a Path_Check_Request message on its active
port, a beacon device shall respond with a Path_Check_Response message to the requesting
device on its active port.
A BRP end device shall detect transmit path faults in direction opposite to beacon flow
through a timeout on non-reception of Path_Check_Response messages from BRP beacon
devices for repeated Path_Check_Request messages. When a BRP end device detects such
a loss on its active port, it shall immediately switch its active port.

– 14 – IEC 62439-5:2016  IEC 2016

7 BRP protocol specification
7.1 MAC addresses
BRP protocol shall use multicast address 01-15-4E-00-02-01 and 01-15-4E-00-02-02. Both

ports of a BRP node shall have the same MAC address for active communication.

7.2 EtherType
The BRP protocol shall use assigned EtherType 0x80E1.

7.3 Fault detection mechanisms
The following fault detection mechanisms are used:
• Link fault detection
This mechanism covers physical layer failures in transmit and receive directions on a link
directly connected to the end node.
• Receive path fault detection
This is accomplished utilizing the beacon message transmission mechanism.
• Transmit path fault detection
This is accomplished utilizing Path_Check_Request and Path_Check_Response
messages. The periodic switchover between active and inactive ports ensures coverage of
all transmit paths in the network.
7.4 BRP end device
7.4.1 State diagram
Figure 5 shows the State diagram for an end device.

Link is Lost on Port 1/Port 2
or Link is Restored on Port
Power Up
1/Port 2
Beacon Received on
Beacon Received on
Port 2
Port 1
FAULT_STATE
Link is Down on Link is Down on
Both Ports or Both Ports or
Beacon Timed Beacon Timed
Out on Both Out on Both
(Link is Lost on Port 1 or Beacon
Ports Ports
Timed Out on Port 1 or
Path_Check_Response Timed Out
or Active Port Swap Timeout) and
Link is Up Port 2
PORT_1_ACTIVE_STATE PORT_2_ACTIVE_STATE
(Link is Lost on Port 2 or Beacon
Timed Out on Port 2 or
Path_Check_Response Timed
Beacon Received on Port 1/
Beacon Received on Port 1/
Out or Active Port Swap
Port 2 or Beacon Timed Out
Port 2 or Beacon Timed Out
Timeout) and Link is Up Port 1
on Port 2 or Link is Lost on
on Port 1 or Link is Lost on
Port 2 or Link is Restored on
Port 1 or Link is Restored on
Port 2 or
Port 1 or
Path_Check_Response
Path_Check_Response
Received on Port 1 or Path
Received on Port 2 or Path
Check Request Interval
Check Request Interval Timer
Timer Expired Expired
IEC
Figure 5 – State diagram for end device
7.4.2 Start-up
An end device shall start up in FAULT_STATE and when a Beacon message is received on
port 1 or port 2, it shall transition to PORT_1_ACTIVE_STATE or PORT_2_ACTIVE_STATE
respectively. It shall either disable unicast MAC address learning on both BRP ports or shall
flush the unicast MAC address learning table whenever a port is made an active port. It shall
save the beacon device MAC address, IP address and Precedence, and the following
information from the Beacon message as current BRP operational parameters:
• VLAN ID
• Beacon Interval
• Beacon Timeout
• Active Port Swap Interval
Whenever a new port is made an active port, an end device shall transmit a Learning_Update
message as the first message on its new active port to update network topology in
infrastructure switches.
7.4.3 Normal operation
End devices shall support independent mechanisms to receive, track and time out Beacon
messages from up to three beacon devices on each of their BRP ports. When a Beacon
message from a new beacon device is received on a port, an end device shall save the
beacon device MAC address, IP address and Precedence from the Beacon message. If the
Precedence of the new beacon device is higher than that of all beacon devices currently not
timed out on both ports, it shall save the current BRP operational parameters (VLAN ID,
Beacon Interval, Beacon Timeout and Active Port Swap Interval) from the Beacon message.

– 16 – IEC 62439-5:2016  IEC 2016

In case of a Precedence tie during comparison between two beacon devices, the device

having the numerically higher MAC address shall be considered to have higher Precedence.

An end device shall send a Path_Check_Request message on its active port once every Path

Check Request Interval, to one of the beacon devices currently not timed out on the active

port, in a round robin manner for each interval. For example, if three beacon devices are

currently active, a BRP end device shall send Path_Check_Request message to beacon

device 1 in the first interval, to beacon device 2 in the second interval and so on.

An end device shall always use a single device MAC address for all traffic sent from/to its

active port. When the active port is switched, the device MAC address shall always be

associated with its current active port.
An end device shall not forward any traffic to/from the CPU on its backup port except for
certain special messages. The special messages to be forwarded from the network to the
CPU on its backup port are the Beacon messages.
An end device shall swap its active port to backup port and vice versa upon expiry of active
port swap interval timer if the backup port is operational.
7.4.4 Fault detection
An end device shall declare a LINK_FAULT on its active or backup port that suffered a
physical layer fault.
An end device shall independently time out non-reception of Beacon message from each
beacon device on each port. It shall declare a BEACON_FAULT on its active or backup port in
which all beacon devices are timed out.
An end device shall declare a PATH_FAULT on its active port, if no Path_Check_Response
message is received for consecutive Path_Check_Request messages exceeding the path
check request retry limit i.e., a Path Check Response message is not received within the Path
Check Retry Limit times the Path Check Request Interval from the first Path_Check_Request
message.
When a fault is declared on the active port, an end device shall swap its active port to backup
port and vice versa, if the backup port is operational. An end device shall transition to
FAULT_STATE if both ports are in some combination of LINK_FAULT and BEACON_FAULT
states.
When both ports are in the PATH_FAULT state, an end device shall try each port in turn, once
every Path Check Retry Limit times Path Check Request Interval from the first
Path_Check_Request message, by transitioning between PORT_1_ACTIVE_STATE and
PORT_2_ACTIVE_STATE, until a valid path to a beacon device is found.
7.4.5 State-Event-Action table
Table 1 lists the parameter values for an end device.

Table 1 – Parameter values for end device

Parameter Value
Port 1 Beacon Device 1 MAC Address Obtained from Beacon message

Port 1 Beacon Device 1 Precedence Obtained from Beacon message

Port 1 Beacon Device 2 MAC Address Obtained from Beacon message

Port 1 Beacon Device 2 Precedence Obtained from Beacon message

Port 1 Beacon Device 3 MAC Address Obtained from Beacon message

Port 1 Beacon Device 3 Precedence Obtained from Beacon message

Port 2 Beacon Device 1 MAC Address Obtained from Beacon message
Port 2 Beacon Device 1 Precedence Obtained from Beacon message
Port 2 Beacon Device 2 MAC Address Obtained from Beacon message
Port 2 Beacon Device 2 Precedence Obtained from Beacon message
Port 2 Beacon Device 3 MAC Address Obtained from Beacon message
Port 2 Beacon Device 3 Precedence Obtained from Beacon message
Current Beacon Interval Obtained from Beacon message
Current Beacon Timeout Obtained from Beacon message
Current Path Check Request Interval 1 times Current Beacon Timeout
Current Active Port Swap Interval Obtained from Beacon message
Current BRP VLAN ID Obtained from Beacon message
Path Check Request Retry Limit 2 (Total number of tries)

The following statements apply to the State-Event-Action table for an end device (see
Table 2):
• Unicast MAC address learning shall be disabled on the two BRP ports or the unicast MAC
address learning tab
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