This read-only PerfTotalCount reports the count of frames received with CRC checksum errors on the DSL port, scoped to the DSL port's current, still-accumulating measurement period (not yet rolled into the interval history). 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 can poll this counter every few minutes while a technician wiggles the customer's line connection to see in real time whether CRC errors are tied to that specific point of contact.