Introduction to time synchronization pt. 3


Maciek Machnikowski


Nuts and Bolts

Session Type




The third part of the “Introduction to time synchronization” trilogy [1][2] introduces the latest advancements in linuxptp 4.0, such as dynamic clock reconfiguration in ts2phc or support for virtual clocks in the tool and the Linux Kernel.

In this episode, we’ll start with a guide to IEEE 1588 profiles - what can you choose from and how will it work under the hood.

This session will explain the fundamental concepts of Precision Time Measurement (PTM), which offers a pathway to enhance the synchronization of time between the Network Interface Card (NIC) and the Central Processing Unit (CPU), and briefly introduce kernel APIs dedicated to supporting it.

The guide will talk about practical techniques for effectively monitoring a PTP-synchronized system and conducting tests on a PTP Hardware Clock (PHC) through the utilization of diverse tools. Notably, tools like “phc_ctl” and “testptp”.

The talk concludes with a practical example of deploying ptp4l and phc2sys in combination with chronyd or ntpd to synchronize the system clock to NTP and PTP time sources using a timemaster tool. This approach can ease the deployment of PTP amongst existing NTP and improve the dependability of time synchronization within a given system.

[1] Part 1: [2] Part 2: