Patent ID: 8848714

Claim:
A packet transfer device that, when a packet is inputted thereinto from an input line, transmit the packet to one or a plurality of output lines, comprising: a power saving control unit for switching the packet transfer device between a sleep mode and a normal mode according to an instruction in the received packet circulating in a network; a receiving/transmission circuit for inputting and outputting the packet; and a packet transfer function unit, including a packet processing unit, a packet transfer switch, and a packet transmitting unit, for transferring an inputted packet to the output line, said packet transfer function unit being located and configured to receive the inputted packet from the packet receiving/transmission circuit, to process the inputted packet receive from the packet receiving/transmission circuit, and to transmit the processed packet back to the receiving/transmission circuit; wherein the power saving control unit halts the packet transfer function unit when the packet transfer device is in the sleep mode, wherein the receiving/transmission circuit is configured to analyze received data to determine whether the received data includes an instruction data of the sleep mode or normal mode or not, and to transfer the received data to the power saving control unit when the received data includes the instruction data, and wherein the receiving/transmission circuit is configured to analyze the received data regardless of whether said packet transfer device is in the sleep mode or not so that said receiving/transmission circuit of said packet transfer device can receive and transfer a sleep mode cancellation signal, even when the packet transfer device is in the sleep mode.