This read-create TruthValue controls whether a B2 byte Degraded Signal (B2DEG) indication, a SONET/SDH signal-quality alarm, is a trigger for this MSP group's protection switchover. It lets the operator decide whether a degrading-but-not-failed signal should alone cause the ring to switch protection, rather than waiting for a hard loss of signal. For example, enabling B2DEGTrigger means a slowly rising bit-error condition detected via the B2 byte will trigger a protection switch before the section fails outright.