A communication apparatus forming a ring network sends a test frame that is not designed to be discarded at a block point in the ring network established to discard the user frame and that is configured to have a data size randomly selected from the data sizes permitted for the user frame, from a first communication port connected to a transfer channel in a first direction in the ring network. The communication apparatus determines that the transfer status of the user frame in the ring network is normal when the sent test frame is received via a second communication port connected to a transfer channel in a second direction in the ring network in a predetermined manner.