A method of operating a root node in which the root node transmits/receives traffic with a plurality of leaf nodes through a plurality of working paths is disclosed, the method including receiving, from a first leaf node, a first signal failure (SF) message indicating an occurrence of a failure on a first working path of the first leaf node, receiving traffic from the first leaf node by switching the first working path to a first protection path, and receiving traffic from remaining leaf nodes aside from the first leaf node while maintaining the working path.