Discuss how it is possible to compensate for clock drift between synchronization points by observing the drift rate over time. Discuss any limitations to your method.

What will be an ideal response?

If we know that the drift rate is constant, then we need only measure it between synchronization points with an accurate source and compensate for it. For example, if the clock loses a second every hour, then we can add a second every hour, in smooth increments, to the value returned to the user. The difficulty is that the clock’s drift rate is liable to be variable – for example, it may be a function of temperature. Therefore we need an adaptive adjustment method, which guesses the drift rate, based on past behaviour, but which compensates when the drift rate is discovered to have changed by the next synchronisation point.