White Rabbit High-availability Seamless Redundancy (HSR)
WR-HSR is a research project to implement the High availability Seamless
Ring (HSR) protocol (IEC 62439-3 Clause 5) on White Rabbit switches and
dual-port end nodes.
The implementation is not part of the roadmap of the White Rabbit
project.
Fig1: HSR typical network topology. (non-wr)
Introduction
HSR guarantees zero-time recovery in case of single point of failure. Including the protocol in WR elements, we could extend HSR features to time and frequency distribution in WR ring networks.
WR-HSR Implementation
Peer-to-Peer Delay Measurement
Fig2: Delay link measurement using Peer Delay mechanisim
Fig3: Peer Delay message exchange diagram
https://www.ohwr.org/project/wr-hsr/uploads/e78e6e4e68ff1a0e61a23e2b04cdc33e/hsr-ring.png
Fig4: Peer-to-Peer Sync/Follow_up message exchange
Fig5: Peer-to-Peer Delay Measurement Flow Diagram
HSR Frame
preamble | destination | source | HSR Ethertype | PathID | LSDU size | Sequence Number | Original Ethertype | payload | CRC |
HSR tag lengh is 6 bytes and is composed of:
- HSR Ethertype: 0x892F
- HSR Path ID: Identifies the path in which a frame was originally injected.
- LSDU size: Payload + HSR tag
- HSR Sequence Number: Sequence number of injected frame
Project information
- Official production documentation: EDMS EDA-02408
- Software
- Frequently Asked Questions
- Users
Contacts
Project
- José Luis Gutiérrez - University of Granada - General questions about the project.
- Javier Díaz - University of Granada - General questions about the project.
Project Status
Date | Event |
01-07-2014 | Start of brainstorming to increase reliability in WR networks. |
01-10-2014 | HSR as first candidate for adding reliability in WR networks. |
12-10-2014 | Starting to study of the HSR protocol and how to implement it for WR |
08-04-2015 | Starting implementation on the WRS |
17-04-2015 | Problem TBD: what about WR syntonization using pure TC? |
Possible solution: fake TC = BC + forwarding sync/follow_up. Problem: switchover will not be 0 time recover | |
20-04-2015 | Porting César's PeerDelay implementation to current version of PPSi |
27-04-2015 | HSR: Adding HSR tag to PTP frames on PPSi |
06-05-2015 | P2P: Starting "TC" implementation (forwarding) |
18-05-2015 | P2P: Residence time for follow_up messages in 2-step implementation |
8 April 2015