PT-7728-PTP: The Key to PRP/HSR Connectivity

Hybrid Redundancy for Scalable Migration

Compliant with IEC 61850 standards, the PT-7728-PTP aims to help both new and existing network infrastructures achieve the highest communication availability required for time-sensitive and mission-critical applications. The PT-7728-PTP provides 24+4G modular connectivity that allows individual and groups of RSTP devices to be connected to PRP/HSR redundant networks over copper, optical fiber, or a mixture of the two.

PRP Redundancy

A PRP Scenario

  • A DANP (dual attached node for PRP) can publish and duplicate packets, and then forward the duplicated packets over two independent LANs.
  • The destination DANP accepts one copy and discards the second copy.
  • Through a RedBox (redundancy box), a SAN (single attached node) can be added to this PRP multipath transmission.

PT-7728-PTP's PRP Redundancy

  • The switch embeds a PRP/HSR module to implement PRP redundancy.
  • Through 24+4G port switching, the PT-7728-PTP can connect numerous SANs to the parallel networks to extend PRP coverage at no extra cost.
  • Leveraging multipath concurrent transmissions, the PT-7728-PHP implements zero-time failover when a single path fails.


HSR Redundancy

An HSR Scenario

  • HSR relies on a ring topology to perform bi-directional transmissions.
  • A SAN can join the HSR by linking a RedBox that duplicates the SAN's packets, transmitting the duplicated packets in both directions and discarding the packets that arrive last.
  • A DANH (DAN for HSR) can either publish or receive redundant packets, the same as DANP.

PT-7728-PTP's HSR Redundancy

  • The switch uses a PRP/HSR module to implement HSR.
  • Leveraging HSR capability, the PT-7728-PTP performs dual-path failover to achieve zero-time redundancy and zero packet loss.
  • The 24+4G switch can connect many SANs for HSR migration, extending the lifetime of legacy devices.




RSTP-to-HSR Coupling

RSTP-to-HSR Coupling

  • Many substations want to add PRP/HSR segments to existing RSTP networks to improve reliability.
  • A single RedBox can be used to couple HSR/PRP to RSTP, but it is risky because of the possibility of single link failures.


  • On the other hand, redundant coupling of HSR and RSTP could result in network failure due to broadcast storms.

PT-7728-PTP's RSTP Grouping

  • The PT-7728-PRP uses a proprietary mechanism to stop broadcast storms, and it enables redundant interconnections between HSR and RSTP segments.



  • The PT-7728-PTP enables multiple interconnections between RSTP and HSR rings, making it easy to migrate groups of RSTP nodes to HSR redundancy.