| 摘要 |
<p>PROBLEM TO BE SOLVED: To omit the management of a data base, a path selection tool, etc., and to attain an economical communication network by sorting the grades of paths according to the reliability and quality of each path and setting a specific path in each ring network for both paths of high and low grades respectively. SOLUTION: The node devices 11 to 19 are connected together in the ring networks 21 and 22, and the node devices 13 and 24 are connected to each other as the bridge nodes. The paths to be set are sorted in classes A to C according to the reliability and quality of each path. Then two paths running opposite to each other are set in each ring network for the path of class A of the highest grade, and a non-short break switching device 31 placed at a receiving terminal selects with no short break one of paths passing through two routes that has higher quality. Meanwhile, the paths running in the single direction are set in each ring network for the paths of classes B and C respectively.</p> |
