This read-only PerfTotalCount reports the count of receive frames discarded for lack of available buffers on the DSL port, scoped to one specific 15-minute bucket out of the 96 stored for that DSL port. Operationally, buffer exhaustion causes silent frame loss even when the physical line itself is clean, pointing to a resource or congestion issue rather than a wiring fault. For example, an admin who sees buffer-exhaustion counts recurring in the same 15-minute slot across multiple days would suspect a scheduled batch job on the customer's network causing a predictable traffic surge.