Patent ID: 8249084
Filing Date: 2012-08-21
Classification: H04L

Abstract:
1. A ring connection control circuit that connects a subring, wherein a plurality of communication devices is connected in series in ring form, and a switching hub, comprising: a first MAC processing unit, which is connected to one end of the subring and sends and receives MAC frames to and from the communication devices; a second MAC processing unit, which is connected to the other end of the subring and sends and receives the MAC frames to and from the communication devices; an STP processing unit, which is connected to the first and second MAC processing units and performs a redundancy control process on the subring based on a spanning tree protocol; a third MAC processing unit, which is connected to the switching hub and sends and receives the MAC frames; and a transfer processing unit, which transfers the MAC frames received by the first MAC processing unit, the second MAC processing unit, and the third MAC processing unit to any one processing unit from the group consisting of the first MAC processing unit, the second MAC processing unit, and the third MAC processing unit based on destination information that is included in the MAC frames; wherein, if the first and second MAC processing units receive from the subring a MAC frame that includes control information for the redundancy control process related to that subring, then output of the relevant MAC frame to the transfer processing unit is restricted and the MAC frame is output to the STP processing unit.