This is a read-only gauge, in milliseconds, tracking the lowest playout FIFO delay observed during this voice call. An admin uses this alongside the high-water mark to see the full range of jitter buffer behavior during the call, helping distinguish a consistently high-delay call from one with wide swings between low and high delay. For example, a large gap between the low-water and high-water marks on the same call would indicate highly variable network jitter rather than a steady, predictable delay.