This read-write value, per its NsThreshold syntax, sets the failure threshold used to determine when this candidate timing source is declared unusable. An admin tunes it to control how tolerant the device is of transient timing-source glitches before actually failing that source over to another candidate. For example, an admin on a particularly noisy timing feed might raise this threshold to avoid unnecessary failovers triggered by brief, non-disruptive glitches (illustrative, since the source MIB has no DESCRIPTION text).