Toward a Practical Deterministic Datapath for 6G End Devices

6G networks aim to achieve seamless integration of wireless and wired technologies through deterministic, end-to-end communication and processing across diverse technological domains (e.g., edge, cloud). While standards like 5G, Time Sensitive Networking (TSN), and Deterministic Networking (DetNet) have introduced significant advancements in predictable communication, much less attention has been given to ensuring deterministic packet processing on end devices. In many cases, especially in data centers, processing remains a primary source of unpredictable jitter since current datapaths - intended as packet processing software layers - focus heavily on optimizing common case latency and throughput, not considering the full tail latency spectrum. This paper provides the first comprehensive end-to-end latency characterization of high-performance packet processing technologies, highlighting their insufficient support for determinism. We propose a high-level design to address this issue and move towards a deterministic datapath for end devices employed in future 6G networks.