Ensuring Reliable and Predictable Behavior of IEEE 802.1CB Frame Replication and Elimination

TL;DR

This paper identifies key limitations in the IEEE 802.1CB-2017 standard for frame replication and elimination in TSN networks and proposes solutions to enhance reliability and safety in real-time Ethernet communications.

Contribution

The paper introduces specific solutions to four fundamental limitations of the IEEE 802.1CB-2017 standard, improving its reliability in time-sensitive networks.

Findings

Simulations demonstrate improved reliability with proposed solutions.

Solutions effectively address sequence recovery and burst size challenges.

Guidelines for implementing IEEE 802.1CB enhancements are provided.

Abstract

Ultra-reliable and low-latency communication has received significant research attention. A key part of this evolution are the Time-Sensitive Networking (TSN) standards, which extend Ethernet with real-time mechanisms. To guarantee high reliability, the standard IEEE 802.1CB-2017 Frame Replication and Elimination for Reliability enables redundant communication over disjoint paths. While this mechanism is essential for time-critical applications, the standard contains some fundamental limitations that can compromise safety. Although some of these limitations have been addressed, none of the previous works provide solutions to these problems. This paper presents solutions to four main limitations of the IEEE 802.1CB-2017 standard. These are 1) choosing match versus vector recovery algorithm, 2) defining the length of the sequence history, 3) setting a timer to reset the sequence history, and 4) dimensioning the burst size in case of link failures. We show how these challenges can be solved by using best- and worst-case path delays of the network. We have performed simulations to illustrate the impact of the limitations and prove the correctness of our solutions. Thereby, we demonstrate how our solutions can improve reliability in TSN networks and propose these methods as guidance for users of the IEEE 802.1CB standard.