A. signal fail, signal degrade, manual switch
B. signal degrade, signal fail, manual switch
C. protection lockout, manual switch, path AIS
D. forced switch, manual switch, signal degrade
E. protection lockout, manual switch, forced switch

A. Switch times would exceed 50 ms for an OC-3 BLSR ring.
B. An equal amount of working and protect bandwidth is required.
C. DCC bandwidth is not large enough to handle K1/K2 processing.
D. There is not enough bandwidth in an OC-3 ring to justify BLSR protection.