The status of Etherring instance. The value 'idle' is initial and normal value. And that means there is no fault on the Ring Network (i.e. the RPL Port is closed). When the RPL port is opened because of the detection of Signal Failure on the Network, the value will change to 'protection'. 'force' and 'manual' shows switch control is performed on the Ring Network. When the switch control is cleared or the Signal Failure is cleared, the value will show 'pending'.