Patent ID: 9306845
Filing Date: 2016-04-05
CPC Classification: H04L,Y02D

Claim Text:
1. A communication system comprising: a first switching device and a second switching device each having a plurality of ports including a bridging port and a first port, and being connected to each other by a communication line via the bridging port; and a third switching device being connected to the first port of the first switching device and the first port of the second switching device via different communication lines, and setting link aggregation for ports to be connection sources of the communication lines, wherein each of the first switching device and the second switching device has: an address table indicating a relation between the plurality of ports owned by the first switching device and the second switching device and addresses existing ahead of the plurality of ports; and a link table by which the first port of the first switching device and the first port of the second switching device logically function as one port, when the first switching device receives a frame at the first port, the first switching device creates abridging frame containing a transmission source address contained in the received frame and an identifier of the first port, and transfers the bridging frame from the bridging port toward the second switching device, when the second switching device receives the bridging frame at the bridging port, the second switching device detects the identifier of the first port and the transmission source address from the bridging frame, and updates the address table of the second switching device based on the identifier of the first port and the transmission source address, wherein, when the first port receives a first frame from a unicast transmission, the first switching device creates the bridging frame containing a first identifier in addition to the transmission source address and the identifier of the first port, when the second switching device detects the first identifier from the bridging frame received at the bridging port, the second switching device updates the address table and discards the bridging frame, wherein, when the first port receives a second frame from a non-unicast transmission, the first switching device creates a third frame as the bridging frame and transfers the bridging frame from the bridging port, the third frame being obtained by further adding a second identifier to the second frame in addition to the identifier of the first port, and when the second switching device detects the second identifier from the bridging frame received at the bridging port, the second switching device updates the address table and restores the bridging frame to a normal frame, and then, transfers the normal frame from a predetermined port.