This read-write Integer32 (1-4095), measured in units of 10 milliseconds, specifies how much variance in the gap duration between sequential tone segments VISM's detector will tolerate, distinct from the tone-duration variance controlled by seqToneDurationDeviation. An admin adjusts this to control how strictly the detector enforces consistent spacing between tone segments in the sequence. For example, an admin dealing with slightly irregular inter-tone spacing on a noisy trunk would raise seqToneGapDurationDeviation to keep valid sequences from being rejected.