Patent ID: 8769157

Claim:
A communication apparatus constituting a ring network where a block point that disconnects the relay of a data frame is set to at least one of a plurality of communication apparatuses that are connected in a ring shape, the communication apparatus comprising: a first relay unit operative to perform a relay process of a data frame in a first direction of the ring network; a second relay unit operative to perform a relay process of a data frame in a second direction, which is different from the first direction, of the ring network; a monitoring unit operative to monitor the internal communication status within the communication apparatus, from the first relay unit to the second relay unit by internally transmitting a supervisory frame between the first relay unit and the second relay unit within the communication apparatus; a block control unit operative to set a new block point inside the communication apparatus to either the first relay unit or the second relay unit when the communication status is abnormal; and a notification unit operative to notify other communication apparatuses that constitute the ring network of information for notifying the switching of a block point in the ring network, which indicates that the new block point has been set.