Ring connection control circuit, ring switching hub, ring ethernet system, and ring connection controlling method

摘要

Problems Solved The present invention solves the problem of how maintain data communication with a normal subring even if a failure occurs in an arbitrary subring. Solution If either of the MAC processing units 11, 12 in one of the ring connection control circuits 10 receives a MAC frame that includes control information for the redundancy control process related to one of the subrings 50 from that subring 50, then output of the relevant MAC frame to the transfer processing unit 15 is restricted and the relevant MAC frame is output to the STP processing unit 13.