| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To efficiently find a loop which is required, when constituting a redundant multicast tree. <P>SOLUTION: In a network system in which a plurality of nodes are connected through a link, such a loop as an originator node acts as both a base point, an end point is configured, and a path is configured in forward and reverse directions of the loop, which procedure is repeated to calculate two multicast trees containing all the modes. Such a method is applied to a multicast-tree calculation device. The multicast-tree calculation device includes a node grouping part which classifies, for grouping, nodes in lower stream for each next transfer destination node of the originator node, and an inter-group link extracting part which extracts a link whose nodes at both ends belong respectively to a different group as a candidate of the link used for constituting a loop, using the groups classified by the node grouping part. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
