Real-Time Performance of OPC UA

OPC UA is a prevalent communication protocol used in the Industrial Internet of Things and machine-to-machine communication, utilizing time-sensitive networking to guarantee real-time requirements. Linux implements time-sensitive networking through various queueing disciplines (qdiscs), including Time Aware Priority, Multiqueue Priority, Earliest TxTime First, and Credit-Based Shaper. Prior studies on these qdiscs have been limited to a few despite their significance. They have often been confined to point-to-point network configurations using proprietary software or specialized hardware. This study builds upon existing research by evaluating all qdiscs in point-to-point and bridged network configurations using open-source software on commercial off-the-shelf hardware. The study identifies the optimal configuration for each qdisc and compares their jitter, latency, and reliability performance. Our results provide a foundation for future research and practical deployments in real-world industrial applications and show that open-source OPC UA on commercial off-the-shelf hardware can effectively support the real-time demands of many industrial applications.