TR54017 defined bitmap status for this line interface: Value is 1 if this line is carrying service. Value is 2 if this line is in a failed state. Value is 4 if this line is in an inhibit state. Value is 8 if this line is looped back. Value is 16 if the other line is in a failed state. Value is 32 if the other line is in an inhibit state. Value is 64 if the other line is looped back. Value is 128 if the manual inhibit is active Note that multiple status conditions may exist at the same time.

The failed state is determined when carrier fails, or the ES threshold is reached, or the consecutive SES threshold is reached.

The inhibit state is set when the manual inhibit setting affects this line or the line is inhibited by the remote end.