Time-Sensitive Networking (TSN) is an emerging real-time Ethernet technology that provides deterministic communication for time-critical traffic. At its core, TSN relies on Time-Aware Shaper (TAS) for pre-allocating frames in specific time intervals and Per-Stream Filtering and Policing (PSFP) for mitigating the fatal disturbance of unavoidable frame drift. However, as first identified in this work, PSFP incurs heavy memory consumption during policing, hindering normal switching functionalities. This work proposes a lightweight policing design called FooDog, which could facilitate sub-microsecond jitter with ultra-low memory consumption. FooDog employs a period-wise and stream-wise structure to realize the memory-efficient PSFP without loss of determinism. Results using commercial FPGAs in typical aerospace scenarios show that FooDog could keep end-to-end time-sensitive traffic jitter <150 nanoseconds in the presence of abnormal traffic, comparable to typical TSN performance without anomalies. Meanwhile, it consumes merely hundreds of kilobits of memory, reducing >90% of on-chip memory overheads than unoptimized PSFP design.

翻译：时间敏感网络（TSN）是一种新兴的实时以太网技术，可为时间关键型流量提供确定性通信。其核心依赖于时间感知整形器（TAS）在特定时间间隔预分配帧，以及基于每流过滤与监管（PSFP）缓解不可避免的帧偏移带来的致命干扰。然而，本工作首次发现，PSFP在监管过程中会消耗大量内存，从而阻碍正常交换功能。本文提出一种名为FooDog的轻量级监管设计，能够以超低内存消耗实现亚微秒级抖动。FooDog采用周期性与流式结构，在保持确定性的同时实现内存高效型PSFP。在典型航空航天场景中使用商用FPGA的测试结果表明：当存在异常流量时，FooDog可将端到端时间敏感流量抖动维持在<150纳秒，与无异常情况下的典型TSN性能相当。同时，其内存消耗仅为数百千比特，相较于未优化的PSFP设计，片上内存开销降低90%以上。