What do Stratum levels in NTP signify?

Stratum levels in the Network Time Protocol (NTP) indicate the hierarchy of time sources within a time synchronization network. The lower the Stratum number, the closer the time source is to an authoritative reference clock, such as an atomic clock or GPS clock.

For example, a Stratum 0 device is a reference clock, while a Stratum 1 server gets its time directly from a Stratum 0 device. Stratum 2 servers get their time from Stratum 1 servers, and this hierarchy continues with higher Stratum numbers representing servers that are further away from the original reference source. This structure allows NTP to provide reliable and accurate time synchronization across distributed networks.

The other choices do not capture the meaning of Stratum in NTP; rather, they pertain to different aspects of network performance or server configuration unrelated to the timing hierarchy.