Delay Analysis and Testing of TAS Mechanism in Time-Sensitive Networks

Time-Aware Shaper(TAS), as an vitally important synchronous scheduling mechanism in Time-Sensitive Networks(TSN), is defined by the IEEE 802.1 Qbv [1] standard. TAS achieves non-waiting transmission of Time-Triggered(TT) streams by using Gate Control List(GCL). This paper analyzes the end-to-end(E2E) latency of time-sensitive flows when using the TAS mechanism. We built a testing platform using TSN switches and a professional tester. In the presence of background flows, we changed some key parameters and conducted multiple sets of tests. The test results indicate that when the TAS mechanism takes effect, it can achieve bounded latency for high priority traffic. In addition, ensuring the match between the arrival of high priority traffic and the GCL is a prerequisite for the high-performance operation of TAS.