Optimize Ethernet Communication using PRP and HSR Redundancy Protocols.

Optimize Ethernet Communication usingPRP and HSRRedundancy Protocols

Schneider Electric 2- Energy – HSR & PRP – Henri Grasset 22/08/2014

HSR or PRP or a mix of?

Single ring HSR is preferred to connect a small amount of IEDs*● HSR is using single ring topology thus no need of additional switches● Plug & Play● It is not possible to connect a laptop to this network but using a Red Box● The communication bandwidth used is “multiplied” thus the number of IEDs is limited*

● Double (or multiple) rings can not help as the bottleneck(s) would be in the rings interconnection (red/quad box)

*: Around 20 for 100Mbit/s

Optional RedBox

Ring A Ring B



PRP is preferred to connect a big amount of IEDs sharing the same application and with no need of either physical network or sub application segregation*

● It is possible to directly connect a laptop to this network● Plug & Play● The communication bandwidth used is “normal” thus the number of IEDs is “not limited”● PRP is usually using star topology thus additional switches are needed

*: during test for example

PRP

Network 1 Network 2

PRP PRP

PRP SwitchPRP Switch



Mix of single rings HSR and PRP is preferred to connect a big amount of IEDs not sharing the same applications or with a need of either network or sub application segregation

● Plug & Play● It is possible to directly connect a laptop to the PRP network and communicate with all the

IEDs

1. HSR Rings● HSR is using ring topology thus no need of additional switches● The amount of IED is small* thus no bandwidth issue

2. PRP network● The amount of IEDs is “not limited”● The amount of switches is optimized

3. HSR/PRP interconnections● Made with 2 Red Boxes per connection



Optimised Network Topology

RedBox RedBox

Network 1

Ring A

HSR HSR

Ring B

Control

Switch


Optimised Network Topology

RedBox 1 RedBox 2 RedBox 3 RedBox 4PRP

Network 1

Ring A

Network 2

HSR HSR

Ring B

PRP Switch

PRP Switch



Conclusion:

● There is no “fit for all” or “Best” solution

● For small amount of IEDs*:● Single ring HSR is preferred

● For big amount of IEDs:● If there is no need of either physical network or sub application segregation

– PRP is preferred

● If there is a need of either physical network or sub application segregation– Mix of single rings HSR and PRP is preferred



Future Optimised Network Topology?

“SmartQuadBox 1

SQuadBox 2

“Smart” QuadBox 3

“Smart“ QuadBox 4

1Gbit HSRWith Multicastfiltering

Ring A

100 Mbit HSR 100 Mbit HSR

Ring B

THANK YOU

IEC 62439 PRP & HSR(Parallel Redundancy Protocol &High-availability Seamless Redundancy)

PRPParallel Redundancy Protocol


PRP (IEC 62439-3 Clause 4)● Differences (with HSR)

● Allows● Mixing single and double network attachment devices on the same LAN (not

redundant and redundant devices)● Thus connect laptops and workstations to the network with standard Ethernet

adapters (not redundant devices)

● Uses off-the shelf components (network interfaces, controllers, switches…)

● HSR:● Ethernet redundancy method DEPENDENT of the HSR Ethernet protocol● DOES NOT Allow Mixing single and double network attachment devices on the

same LAN (not redundant and redundant devices)● Thus connect laptops and workstations to the network with standard Ethernet

adapters must be done by RedBox

● Uses HSR components (network interfaces, controllers, switches…)


PRP Network Architecture

switch

DANP

switch

Local Area Network B

DANP

switchswitch

switch

SAN

switch

DANP DANP

Local Area Network A

DANPDANP

Two Ethernet networks (LANs) , completely separated, operate in parallel. Each doubly attached node with PRP (=DANP) has an interface to each LAN.A DANP source sends a frame simultaneously on both LANs.attentionA DANP destination receives in normal operation both frames and discards the duplicate.A singly attached destination only receives one.If a LAN fails, a DANP destination operates with the frames from the other LAN.

= Doubly Attached Node(PRP)

DANP SAN

PRP “A” framesPRP “B” framesstandard frames

= SinglyAttachedNode

SAN

SAN

source

destinations destinations



switch

DANP

switch


DANP

switchswitch

switch

SAN

switch

DANP DANP


DANPDANP



DANP SAN



SAN

SAN

source




switch

DANP

switch


DANP

switchswitch

switch

SAN

switch

DANP DANP


DANPDANP



DANP SAN



SAN

SAN

source


= RedBox(SAN / PRP)


Px40 Network Topology example

LAN B of any typeLAN A of any type

Px4x Px4x Px4x


Frame identification

●PRP● PRP “tag” is at the end of the frame in order to be interoperable with today’s (not PRP) switches

●HSR● HSR “tag” is at the beginning of the frame in order to transmit further without delay

HSRHigh-availability Seamless Redundancy


HSR (IEC 62439-3 Clause 4)● Differences with PRP

● DOES NOT Allow Mixing single and double network attachment devices on the same LAN (not redundant and redundant devices)

● Thus connect laptops and workstations to the network with standard Ethernet adapters must be done by RedBox

● Uses HSR components (network interfaces, controllers, switches…)

● PRP:● Ethernet redundancy method independent of any Ethernet protocol● Allows

● Mixing single and double network attachment devices on the same LAN (not redundant and redundant devices)

● Thus connect laptops and workstations to the network with standard Ethernet adapters (not redundant devices)

● Uses off-the shelf components (network interfaces, controllers, switches…)


HSR Network Architecture

“An” Ethernet network Ring(s) connecting each doubly attached node with HSR (=DANH).A DANH source sends a frame simultaneously on both ports and blocks the sent messages.All DANH receive in normal operation both frames and instantaneously forwards them.A DANH destination receives in normal operation both frames, forwards them and discards the duplicate.A singly attached destination only receives one via a RedBox.If a link fails, a DANH destination operates with the frames from the other path.



HSR Network Architecture

“An” Ethernet network Ring(s) connecting each doubly attached node with HSR (=DANH).A DANH source sends a frame simultaneously on both ports and blocks the sent messages.All DANH receive in normal operation both frames and instantaneously forwards them.A DANH destination receives in normal operation both frames, forwards them and discards the duplicate.A singly attached destination only receives one via a RedBox.If a link fails, a DANH destination operates with the frames from the other path.



Px40 Network Topology example

Px4x Px4x Px4x


Frame identification

●PRP● PRP “tag” is at the end of the frame in order to be interoperable with today’s (not PRP) switches

●HSR● HSR “tag” is at the beginning of the frame in order to transmit further without delay

Optimize Ethernet Communication using PRP and HSR Redundancy Protocols.

Documents

prp prp switch slide

energy hsr prp henri

example prp network

limited prp

prp iec

single ring hsr

hsr ring b prp switch

gbit hsr