Description: The mandatory operational state of the subsystem. The testing(3) state indicates that no operational functions can be passed. If ctDARegistryAdminStatus is down(2) then ctDARegistryOperStatus should be down(2). If ctDARegistryAdminStatus is changed to up(1) then ctDARegistryOperStatus should change to up(1) if the subsystem is ready to function; it should change to dormant(5) if the subsystem is waiting for external actions; it should remain in the down(2) state if and only if there is a fault that prevents if from going to the up(1) state. The notPresent state is a refinement on the down state which indicates that the relevant interface is down specifically because some component (typically, a hardware component) is not present in the managed system. The lowerLayerDown state is also a refinement on the down state. This new state indicates that this system runs on top of one or more interfaces (see ifStackTable) and that this system is down specifically because one or more of these lower-layer interfaces are down.