This read-only PerfTotalCount reports the count of frames truncated because the DSL receiver overran and had to cut a frame short, scoped to the full previous calendar day's totals for the DSL port. Operationally, truncated frames are lost data, and a rising count suggests the receiver is being overwhelmed faster than it can process incoming bits. For example, a support agent handling a first-thing-in-the-morning ticket pulls yesterday's truncated-frame total to see if the issue was present all day yesterday or only just started.