. There is a lot more information on these parameters and what they mean in Chapter 5, SO if you want to fully understand parts of this chapter, then you should be aware of the basic ideas from Chapter 5. But at a minimum, these are the main metrics you need to be concerned about, SO the rest of the chapter explains them in more detail. The section "Clock Performance" later in the chapter outlines how these timing metrics are applied to each clock type. 9.3.1 Maximum Absolute Time Error As described in Chapter 5, the maximum absolute time error, or max|TE|, is the maximum absolute value of the (unfiltered) time error (TE) observed over the course of a measurement. While TE is a measure of how far apart two clocks are from each other at any one instant, max|TE| is the max- imum value that was reached over the period it was being observed or measured. In shorthand, TE indicates how bad it is now, whereas max|TE| says how bad it ever got. The value for max|TE| is one of the most common values measured during testing for network end- to-end timing. Similarly, when talking about meeting a phase alignment requirement between two points in an application, max|TE| is the metric to be monitoring. But when applied to a standalone clock, max|TE| represents the maximum amount of noise that a clock generates during a test run when given ideal inputs. Theoretically, the value of max|TE| could vary over time, and some unwanted noise might intervene to cause it to move more than expected. It is possible that if this state persists only for a short dura- tion, it might not be an issue for the end application. Many times, this value is averaged over a longer period (typically 1000 s) to give an expected long-term average. This averaged value is known as the constant TE (cTE), and dynamic TE (dTE) is the short-term variation of the TE. When the clock is functioning normally, the time output of the T-BC and the T-TSC should be ac- curate to within the max|TE| limits. This value includes all the noise components, which means the cTE 