| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve accuracy of normality confirmation to a ring network. <P>SOLUTION: A communication device 10 constituting a ring network transmits a test frame, which is excluded from disposal targets at a block point 106 where a user frame is discarded, and which has a data length that is set at random from data lengths that can be assumed by the user frame, via a first communication port connected to a transmission path in a first direction of the ring network. The communication device 10 determines that a transmission state for the user frame in the ring network is normal in the case that the transmitted test frame is acquired in a predetermined form via a second communication port connected to a transmission path in a second direction of the ring network. <P>COPYRIGHT: (C)2012,JPO&INPIT |
