Patent ID: 8014302

Claim:
A communication node comprising: a routing information storing unit configured to store, as routing information, node information indicating a succeeding node and a preceding node in a ring network using a distributed hash table; and a routing information updating unit configured to update the node information stored in the routing information storing unit, wherein when the succeeding node becomes inaccessible, the routing information updating unit acquires node information indicating a preceding node from one predetermined node that is made accessible on the network at all times, and based on the acquired node information, the routing information updating unit determines whether or not the node that has supplied the node information satisfies a determination criterion for becoming its succeeding node; the routing information updating unit designates the node that has supplied the node information as its succeeding node if the determination criterion for becoming the succeeding node is satisfied, while the routing information updating unit acquires node information from the preceding node indicated by the acquired node information if the determination criterion for becoming the succeeding node is not satisfied; and the routing information updating unit determines whether or not the node that has supplied the node information satisfies the determination criterion for becoming its succeeding node.