How Network Time Protocol (NTP) Works: Clock Synchronization Explained
OSTechNix, Friday, July 10th, 2026
An explainer on how NTP synchronizes device clocks across IP networks using timestamps and stratum hierarchy.
This guide explains how the Network Time Protocol synchronizes device clocks over IP networks. NTP uses four timestamps (T1-T4) to estimate network delay, compensate for clock drift, and continuously adjust the local clock, applying small corrections gradually via slewing to avoid clock jumps.
It relies on a hierarchical stratum system, with highly accurate atomic or GPS clocks at Stratum 0 serving as primary time sources. Rather than blindly trusting a single master, NTP combines delay estimation, statistical filtering, multiple time sources, and continuous clock discipline to maintain accurate, common time across participating devices.