This counter records the number of background errored blocks (BBE) accumulated during the current 15-minute interval on the local DS1 line, where a block is a 1-byte unit and BBE counts blocks with errors that occur in non-errored seconds. Background errors are less severe than those occurring in errored seconds, but they still represent data integrity issues that monitoring systems should track. Network engineers use BBE to gauge overall line health and to trend whether the line is gradually degrading.