Flexibilis Ethernet Switch with HSR

Flexibilis LogoFlexibilis Ethernet Switch with High-availability Seamless Redundancy support (FES-HSR) is a triple speed (10Mbps/100Mbps/1Gbps) Ethernet Layer 2 switch compatible with IEC 62439-3 Clause 5.

High-availability Seamless Redundancy

High-availability Seamless Redundancy (HSR) is an emerging standard (IEC 62439-3 Clause 5) providing redundancy for Ethernet networks. Typical HSR topology is a ring, the source node duplicates all the frames it has to send and sends them using two different paths to their destination. If either one of the paths is broken, due to link failure or node failure, the frames are still able to reach their destination. The benefit of HSR, when compared to Rapid Spanning Tree Protocol (RSTP), is its zero-time recovery – single network faults in the ring will not result in any frame loss.

Originally HSR was targeted for smart grid electrical substation automation, but it can also be employed in other critical networking applications such as industrial automation, motion control and military communication.

Typically HSR rings consist of three kinds of nodes

  • End-nodes
  • RedBoxes
  • QuadBoxes

End-nodes have at least two external Ethernet ports, to connect to one HSR ring. Sensors such as IEDs (Intelligent Electronic Devices) and cameras, and merging units in substation automation are examples of End-nodes.

RedBox (or Redundancy Box) is an entity that has three external Ethernet ports. Two of the ports are connected to an HSR ring and one port is a traditional Ethernet port. RedBoxes are used to connect non- HSR nodes to HSR rings.

QuadBox or Quadruple Port Device is a device connecting two HSR rings to each other. As the QuadBox itself is a single point of failure, two QuadBoxes are typically used between HSR rings.

Built-in Precision Time Protocol Support

Precision Time Protocol (PTP), defined in IEEE standard 1588, enables precise synchronization of device clocks in packet based networks. Devices are automatically synchronized to the most accurate clock in the network. This protocol is used in applications such as test and measurement, power-line management, industrial automation and telecom.

HSR is typically used in applications where time synchronization is also needed. Therefore PTP support is an integral part of FES-HSR IP cores. In all versions of FES-HSR IP cores there is always a transparent clock between the ring ports. When used as an End-node the FES-HSR IP core contains an ordinary clock and when it is used as a RedBox or QuadBox the FES-HSR IP core has a boundary clock between the rings.

When using Gigabit fiber Ethernet FES-HSR IP core is able to achieve nanosecond class accuracy in clock transfer.

For pricing or additional technical information, please contact Flexibilis Oy by visiting www.flexibilis.com.


  • Ethernet Layer-2 switch
  • Wire-speed packet forwarding
  • Non-blocking operation
  • Reliable Store-and-Forward operation with data integrity checking
  • Compatible with IEC 62439-3 Clause 5 “High-availability Seamless Redundancy (HSR)”
  • HSR End-node, HSR RedBox and HSR QuadBox support
  • Time and frequency synchronization using IEEE1588-2008 Precision Time Protocol v2
  • Transparent switch functionality between HSR ring ports
  • Boundary clock functionality between HSR rings in QuadBox
  • Triple-speed (10Mbps/100Mbps/1Gbps), full-duplex operation on all ports
  • All of the ports of FES-HSR can be either copper or fiber Ethernet interfaces, or connected to other FPGA blocks
  • Interface options - MII, GMII, RMII and RGMII
  • Automatic polling of connected Ethernet PHY interface chips

Jump to

Block Diagram

FES-HSR is available in two different configurations:
4-port FES - HSR (End-node / RedBox)
6-port FES - HSR (QuadBox)

Ordering Information

This IP core is supported and sold by Flexibilis, contact Flexibilis at contact@flexibilis.com or visit their website at www.flexibilis.com for more information.


Information Resources
Flexibilis Ethernet Switch IP Core Product Brief
1.0 6/9/2011 PDF 763.8 KB
Flexibilis Ethernet Switch with High-availability Seamless Redundancy (FES-HSR) Product Brief
1.0 6/9/2011 PDF 668 KB

*By clicking on the "Notify Me of Changes" button, you agree to receive notifications on changes to the document(s) you selected.

Like most websites, we use cookies and similar technologies to enhance your user experience. We also allow third parties to place cookies on our website. By continuing to use this website you consent to the use of cookies as described in our Cookie Policy.