[1] MTIE measurements can be used to detect clock instability that can cause data loss on a communications channel.
Phase error (usually measured in nanoseconds) is calculated for an observation interval.
This phase shift is known as time interval error (TIE).
Each time the peak-to-peak distance between the largest and smallest TIE in that window is noted.
Plotting MTIE vs. different observation interval duration gives a chart useful for characterizing the stability of the clock.