Patent ID: 7366112

Claim:
A communication network system formed of a plurality of links of different attributes, comprising: means for, when transferring communication data from a transmission source to a destination node by using a first path, at the time of the selection of a route to the destination node conducted by said transmission source node, setting up a data base covering all the links of different attributes and generating information of a route whose metric (cost) is the minimum and in which information link attributes are described by using the data base, and at the time of setting said first path based on the route information, confirming an attribute of a link managed by each node on the first path route and when determining that an attribute of a link managed by a first node is different from an attribute of a link managed by the transmission source node, discriminating a second node which exists closer to the destination node than the first node on the route of the first path and which has the same attribute as the attribute of the link managed by the transmission source node, and means for determining that setting of a second path which can accommodate the first path from said first node to the second node is necessary and setting the second path.