Time synchronization in networks is critical for enabling coordination and consistency across distributed systems, especially in industrial control, autonomous systems, and high-frequency trading. This project explores the use of P4-programmable data planes to enhance time synchronization accuracy using the Precision Time Protocol (PTP).
Traditionally, synchronization is managed in software running on control planes. However, the rising demand for nanosecond-level precision necessitates offloading time-critical computations to the data plane itself. In this project, we implemented a P4-based PTP Sync message parser that processes synchronization packets directly in the switch pipeline. A custom extern written in MicroC was used to implement servo computation logic inside the data plane, enabling real-time clock correction.
The approach includes timestamp extraction, clock offset calculation, and slope estimation for skew correction. By using registers to store timestamps and compute delay and offset metrics in-flight, our method significantly reduces jitter and processing delay. The MicroC extern plays a vital role in implementing the linear regression-based servo algorithm, making it efficient and hardware-compatible.
This integration of computation and packet processing in the switch demonstrates a scalable and accurate model for distributed clock synchronization. Compared to software-based implementations, this approach improves determinism and minimizes packet processing delay.
In conclusion, implementing the computation in the data plane using extern MicroC helps increase both the accuracy and precision of clock synchronization, making it a powerful method for next-generation time-sensitive networked systems.