The present invention relates to a ring system, in particular to a ring control node which increases the upper limit of the number of nodes that can be arranged on one ring by a BLSR control and conforms to an increase in line capacity and the scale of a system. The ring control node made of a plurality of nodes for performing ring control, and spans for connecting the plurality of nodes in a ring shape, and each of the nodes detects a fault occurring in a span between itself and another node adjacent thereto, and transmits the fault information to the other node using, as a destination, a span ID assigned to the span.