Time-Sensitive Networking (TSN) enables the transmission of multiple traffic types within a single network. While the performance of high-priority traffic has been extensively studied in recent years, the performance of low-priority traffic varies significantly between different TSN forwarding algorithms. This paper provides an overview of existing TSN forwarding algorithms and discusses their impact on best-effort traffic. The effects are quantified through simulations of synthetic and realistic networks. The considered forwarding mechanisms are Strict Priority (SP), Asynchronous Traffic Shaper (ATS), Credit-Based Shaper (CBS), Enhanced Transmission Selection (ETS), and Time-Aware Shaper (TAS). The findings indicate that ATS, CBS, and ETS can significantly reduce queuing delays and queue lengths for best-effort traffic when compared to SP and TAS. This effect is enhanced when the reserved bandwidth for high priority queues - using CBS, ATS, or ETS - is reduced to the lowest possible value, within the reserved rate and latency requirements. Specifically, the simulations demonstrate that the choice of forwarding algorithm can improve the performance of low-priority traffic by up to twenty times compared to the least effective algorithm. This study not only provides a comprehensive understanding of the various TSN forwarding algorithms but can also serve as guidance at networks' design time to improve the performance for all types of traffic.

翻译：时间敏感网络（TSN）支持在单一网络中传输多种流量类型。尽管近年来高优先级流量的性能已得到广泛研究，但低优先级流量在不同TSSN转发算法下的性能表现差异显著。本文系统综述了现有TSN转发算法，并探讨了它们对尽力而为流量的影响。通过合成网络与真实网络的仿真实验对影响效应进行了量化分析。所考察的转发机制包括严格优先级（SP）、异步流量整形器（ATS）、基于信用的整形器（CBS）、增强传输选择（ETS）以及时间感知整形器（TAS）。研究结果表明，与SP和TAS相比，ATS、CBS和ETS能显著降低尽力而为流量的排队延迟与队列长度。当采用CBS、ATS或ETS的高优先级队列预留带宽在满足预留速率和延迟要求的前提下降至最低值时，这种改善效果更为显著。具体而言，仿真实验表明转发算法的选择可使低优先级流量性能较最低效算法提升最高达二十倍。本研究不仅提供了对各类TSN转发算法的全面理解，还可为网络设计阶段优化全类型流量性能提供指导依据。