This read-only gauge provides a Cell Error Ratio (CER) measurement for an ATM Virtual Path during a reference period, expressed as a percentage multiplied by 100 (so a value of 1000 represents 10% errors), based on ITU-T Recommendation I.356. The CER is calculated from cells that arrive with bit errors or are corrupted during transmission, and this metric directly reflects link quality on the ATM path. ATM network operators monitor this to track data link reliability and trigger corrective actions (such as rerouting traffic or activating backup circuits) when error rates exceed service level agreements.