A read-write enumerated value enabling or disabling C-bit parity checking on the DS3-ATM interface, defaulting to enable but recommended disabled when connected to an M23-configured interface. A mismatch between this setting and the far-end DS3 framing format is a common cause of a physical layer that looks up but reports persistent framing or parity errors. When connecting to a carrier's M23-configured DS3 interface, the admin would set cmDS3AtmCbitParityEnable to disable to match the far end's framing format and avoid spurious parity errors.