Patent ID: 7953220

Claim:
A method of controlling a network switching device, wherein the network switching device comprises an interface block having a plurality of physical interface blocks capable to connect to connection lines, the interface block being capable to send and receive, through the connection lines, packets having associated destination-address information; a first switching block capable to perform a switching-determination process determining a connection line to which the received packets should be outputted, based on the destination-address information that is associated with the received packets; and one or more second switching blocks capable of performing the switching-determination process instead of the first switching block, wherein the first switching block and the second switching block are each provided with a plurality of switchable determination-operation modes as operation modes for the switching-determination process, the plurality of determination-operation modes including a first determination-operation mode and a second determination-operation mode with less power consumption than the first determination-operation mode, and wherein the method comprises; (A) in order to effect a seamless switchover without interruption of the switching-determination process, from the switching-determination process currently effected by the first switching block, to a determination-operation mode that is different from the determination-operation mode of the first switching block, performing a mode-process including setting the determination-operation mode of a target switching block to the determination-operation mode that is different from the determination-operation mode of the first switching block while the first switching block continues handling the switching-determination process on-line, the target switching block being one switching block selected from the second switching blocks, and (B) then performing a seamless switchover process by switching over the switching-determination process to the target switching block effecting the determination-operation mode that is different from the determination-operation mode of the first switching block, instead of the first switching block, after completion of the process of setting the determination-operation mode of the target switching block.