Patent ID: 7054265

Claim:
A communication apparatus connectable to a network which permits communication across a plurality of hierarchical layers, comprising: (i) lower-layer apparatuses which are connected with communication lines of a lower layer and communication lines of an upper layer and have means for line switching in the lower layer, wherein the lower layer is a lower layer as defined by the layer hierarchy of the Open System Interconnection (OSI) reference model as set by the International Standards Organization (ISO) and the upper layer is an upper layer as defined by the layer hierarchy of the OSI reference model as set by the ISO; and (ii) upper-layer apparatuses which are connected with the communication lines of the upper layer and have means for line switching in the upper layer, wherein said communication apparatus detects line failure and coordinates line switching by the line-switching means of the lower and upper-layer apparatuses by using failure information on the lower and upper-layer communication lines.