This read-only Integer32 reports the number of SONET Section-layer Byte Interleaved Parity errors detected on this OC-3 port during the current 15-minute period. It tells an administrator whether the section-layer signal integrity is degrading, an early indicator of a failing optical link before a full loss of signal occurs. For example, an operator seeing this counter climb steadily might schedule a fiber inspection before the link degrades to a hard failure.