This object reports a numeric threshold value (typically a BER ratio like 1e-5 or 1e-4) for SONET line-layer signal degradation using bit-error-based detection. When the measured bit error rate exceeds this threshold during the standard monitoring period, the system declares signal degradation and may trigger alarms or protection switching. A concrete example would be '1e-5', meaning if the SONET line-layer BER exceeds 1 bit error per 100,000 transmitted bits, degradation is declared.