Multi-Layer Redundancy with PRP, RSTP & Precision NTP/PTP
INDUSTRY
Power & Energy – 220kV Digital Substation | Vietnam
A 220kV digital substation requires a highly available communication infrastructure to support IEC 61850 protection, control, monitoring, and engineering systems, together with accurate and reliable time synchronization.CHALLENGES
The network must maintain communication even when individual network components fail, while supporting different levels of redundancy across the substation:- Protect critical communication against single link or switch failures.
- Provide seamless redundancy for PRP-capable IEC 61850 devices.
- Maintain resilient Layer 2 connectivity within the network infrastructure.
- Deliver consistent NTP/PTP synchronization across redundant network paths.
- Provide a flexible architecture for future integration of additional PRP and non-PRP devices.
SOLUTION PROVIDED
ATOP designed a multi-layer redundancy architecture combining PRP and RSTP, supported by the NTS8610 NTP/PTP Grandmaster and RHG9728 Managed Rackmount Switches, both IEC61850-3 certified for substation network systemsPRP – Device-Level Redundancy
Critical IEC 61850 devices are connected to two independent networks: PRP LAN A and PRP LAN B. PRP provides two parallel communication paths, allowing PRP-capable devices to continue communication through the healthy LAN without network reconvergence when one path fails.
RSTP – Network-Level Redundancy
Within the individual LAN infrastructure, RHG9728 switches use RSTP to provide redundant Layer 2 paths. RSTP protects the switching infrastructure against link or switch failures while preventing Layer 2 loops. This complements PRP by providing resilience inside each PRP LAN, rather than replacing the PRP mechanism.
This combination creates a layered approach to availability: PRP protects device connectivity, while RSTP strengthens the underlying switching infrastructure.
Precision NTP/PTP Timing
NTS8610 NTP Server & PTP Grandmaster, referenced by GPS, distributes NTP and IEEE 1588 PTP through the redundant network paths. Critical devices receive a common and accurate time reference for event recording, protection coordination, disturbance analysis, and system monitoring.
Future-Ready RedBox Capability
The RHG9728 is planned to support RedBox PRP functionality, providing a future path to integrate non-PRP devices into the PRP architecture without requiring every field device to be natively PRP-capable.
SYSTEM TOPOLOGY
RESULTS
- Multi-layer network redundancy combining PRP and RSTP.
- Seamless device-level redundancy for PRP-capable IEC 61850 equipment.
- Resilient Layer 2 infrastructure through RSTP within each network.
- Reliable NTP/PTP timing from a GPS-referenced NTS8610.
- Reduced impact of link or switch failures on critical substation communications.
- A flexible and scalable architecture for future PRP integration through RHG9728 RedBox functionality.
KEY VALUE
PRP for device redundancy.RSTP for network infrastructure resilience.
NTP/PTP for precision timing.
RHG9728 for a robust, scalable IEC 61850 switching platform.
