This gauge measures the count of errored seconds at the path level (type A path errors) detected by the remote endpoint during a 15-minute measurement period. A network engineer watches this metric to identify data corruption problems that may be intermittent or environment-related (noise, cross-talk, or signal degradation). For example, a value of 3 means the far-end equipment detected error conditions in 3 separate seconds, which typically requires investigation of line quality.