Siemens RUGGEDCOM RS950G, Installation Manual

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Chapter 1
Introduction
RUGGEDCOM RS950G
Installation Guide
4 Parallel Redundancy Protocol
requires reconfiguration of the active network topology over redundant physical links, HSR and PRP provide hitless
network recovery through the use of information replication.
CONTENTS
• Section 1.4.1, “Parallel Redundancy Protocol”
• Section 1.4.2, “High Availability Seamless Redundancy”
Section 1.4.1
Parallel Redundancy Protocol
Parallel Redundancy Protocol (PRP) provides hitless network recovery by replicating information over two
physically independent Ethernet networks. The following illustrates a typical PRP network:
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Figure 2: PRP Network Design
1. Sending IED 2. RUGGEDCOM RS950G 3. Network A 4. Network B 5. RS900 6. IED 7. Receiving IED
NOTE
PRP expands the Ethernet frame by 6 octets due to RCT (Redundancy Check Trailer). Generation of PRP
supervision frames also consumes bandwidth. As a result, the network designer should keep in mind
the overhead introduced by the PRP network when calculating the network capacity.
Section 1.4.2
High Availability Seamless Redundancy
The basic principle behind High-availability Seamless Redundancy (HSR) is the replication of frames over both sides
of the HRS ring. The following illustrates a typical HSR network: