This read-only PerfTotalCount reports the count of frames received with CRC checksum errors on the DSL port, scoped to the running total for the current calendar day so far. Operationally, CRC errors are a direct measure of line-quality problems, since they indicate data was corrupted somewhere on the copper loop. For example, an admin polling today's running CRC-error total every hour can watch in near-real-time whether a suspected noise source correlates with specific times of day.