NTP uses a hierarchical, semi-layered system of time sources. Each level of this hierarchy is termed a stratum and is assigned a number starting with zero for the reference clock at the top. A server synchronized to a stratum n server runs at stratum n + 1. The number represents the distance from the reference clock and is used to prevent cyclical dependencies in the hierarchy. Stratum is not always an indication of quality or reliability; it is common to find stratum 3 time sources that are higher quality than other stratum 2 time sources. A brief description of strata 0, 1, 2 and 3 is provided below.
ntp uses a hierarchical semi-layered system of time sources each level of this hierarchy is termed a stratum and is assigned a number starting with zero for the reference clock at the top a server synchronized to a stratum n server runs at stratum n + 1 the number represents the distance from the reference clock and is used to prevent cyclical dependencies in the hierarchy stratum is not always an indication of quality or reliability; it is common to find stratum 3 time sources that are higher quality than other stratum 2 time sources a brief description of strata 0 1 2 and 3 is provided below