1. Optimize Ethernet Communication using PRP and HSR Redundancy Protocols

2. 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
Ring A
Ring B
Optional RedBox

3. HSR or PRP or a mix of?
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 Switch

4. HSR or PRP or a mix of?
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
HSR Rings
HSR is using ring topology thus no need of additional switches
The amount of IED is small* thus no bandwidth issue
PRP network
The amount of IEDs is “not limited”
The amount of switches is optimized
HSR/PRP interconnections
Made with 2 Red Boxes per connection
*: Around 20 for 100Mbit/s

5. Optimised Network Topology
HSR
HSR
Ring A
Ring B
Control
RedBox
RedBox
Network 1
Switch

6. Optimised Network Topology
HSR
HSR
Ring A
Ring B
PRP
RedBox 1
RedBox 2
RedBox 3
RedBox 4
PRP Switch
Network 1
PRP Switch
Network 2

7. HSR or PRP or a mix of? 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
*: Around 20 for 100Mbit/s

8. Future Optimised Network Topology?
100 Mbit HSR
100 Mbit HSR
Ring A
Ring B
1Gbit HSR
With Multicast
filtering
“Smart
QuadBox 1
SQuadBox 2
“Smart“ QuadBox 4
“Smart” QuadBox 3

9. THANK YOU

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

11. PRP Parallel Redundancy Protocol

12. 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…)

13. PRP Network Architecture
PRP “A” frames
PRP “B” frames
standard frames
source
DANP
DANP
= Doubly Attached Node
(PRP)
SAN
= Singly
Attached
Node
switch
switch
Local Area Network A
Local Area Network B
switch
switch
switch
switch
SAN
DANP
DANP
DANP
DANP
DANP
SAN
SAN
destinations
destinations
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.attention
A 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.

14. PRP Network Architecture
PRP “A” frames
PRP “B” frames
standard frames
source
DANP
DANP
= Doubly Attached Node
(PRP)
SAN
= Singly
Attached
Node
switch
switch
Local Area Network A
Local Area Network B
switch
switch
switch
switch
SAN
DANP
DANP
DANP
DANP
DANP
SAN
SAN
destinations
destinations
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.attention
A 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.

15. PRP Network Architecture
PRP “A” frames
PRP “B” frames
standard frames
source
SAN
= Singly
Attached
Node
DANP
DANP
= Doubly Attached Node
(PRP)
= RedBox
(SAN / PRP)
switch
switch
Local Area Network A
Local Area Network B
switch
switch
switch
switch
SAN
DANP
DANP
DANP
DANP
DANP
SAN
SAN
destinations
destinations
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.attention
A 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.

16. Px40 Network Topology example
LAN B of any type
LAN A of any type
Px4x

17. Frame identification PRP HSR
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

18. HSR High-availability Seamless Redundancy

19. 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…)

20. HSR Network Architecture
PRP “A” frames
PRP “B” frames
standard frames
“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.

21. HSR Network Architecture
PRP “A” frames
PRP “B” frames
standard frames
“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.

22. Px40 Network Topology example
Px4x

23. Frame identification PRP HSR
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