This read-only Counter reports the number of erred frames received on the data port in this interval. Operationally, erred receive frames indicate corrupted data arriving on the serial link during that window, useful for correlating with a specific time of day. For example, if this interval's error count rises while the DSL-side counters for the same port stay clean, an admin would suspect the fault is specific to the serial interface itself rather than the DSL line.