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.

翻译：超可靠低延迟通信已获得广泛研究关注。时间敏感网络（TSN）标准是该演进的关键组成部分，它通过实时机制扩展了以太网功能。为确保高可靠性，IEEE 802.1CB-2017《帧复制与消除可靠性》标准支持通过不相交路径进行冗余通信。尽管该机制对时间关键型应用至关重要，但标准中存在若干可能危及安全性的根本性局限。虽然部分局限已被指出，但此前研究均未提供解决方案。本文针对IEEE 802.1CB-2017标准的四项主要局限提出解决方案：1）匹配恢复算法与向量恢复算法的选择；2）序列历史长度的定义；3）序列历史重置定时器的设置；4）链路故障时突发数据单元规模的配置。我们论证了如何利用网络的最优与最差路径延迟解决上述问题。通过仿真验证了这些局限的影响及解决方案的正确性，从而展示了所提方法对提升TSN网络可靠性的作用，并建议将这些方法作为IEEE 802.1CB标准用户的实践指南。