| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a relay network by which an external device can detect failures of a transmission path in a short period of time. <P>SOLUTION: Ports 21, 22 for external connection are connected with the external device. A port state monitoring part 51 classifies the ports 21, 22 for external connection into groups beforehand, and stores the correspondence between the ports 21, 22 for external connection and the groups. The port state monitoring part 51 detects the change of the states of the ports 21, 22 for external connection. When the change of the state of either of the ports for external connection is detected with the port state monitoring part 51, a group state management part 52 notifies the other nodes constituting the relay network of state information including information of the state of the group corresponding to the port for external connection whose change of the state is detected. When receiving the state information from any one of the other nodes, the group state management part 52 changes the state of the port for external connection belonging to the group corresponding to the state of the group included in the state information. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
