PTPd

PTPd is an open source implementation of the Precision Time Protocol for Unix-like computers.

Derivatives

Accuracy

PTPd accuracy depends on how IEEE 1588 packets are timestamped on the participating machines. Currently, IEEE 1588 packets are timestamped in software in most implementations, i.e., interrupt latency, OS scheduling, and other software issues influence the accuracy of the acquired timestamps, and therefore, the accuracy of time synchronization. However, some hardware supports recording of timestamps in hardware, making it possible to acquire more precise send and receive timestamps. Software supporting this feature is starting to emerge providing increased and load independent accuracy. For example, a modified PTPd is available.

A test in 2010 on an Intel Gigabit Network card noted offset converging to varying between around 1–100 microseconds in a pure software implementation, and to around a microsecond when using hardware assisted PTP.[3]

References

  1. "Precision Time Protocol Daemon - ptpd2". Retrieved 2011-08-23.
  2. "ptpv2d". Retrieved 2010-06-24.
  3. "Hardware assisted PTPd home page". BME-MIT, Hungary. Retrieved 2011-03-20.

External links

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