Patent ID: 8179904

Claim:
A packet transfer device comprising: a sorting processor unit that sorts a received packet; a bandwidth controller that controls a network bandwidth for receiving a packet; a transfer processor that processes a transfer of the received packet of a protocol requiring an acknowledgment; a storage unit that stores the received packet according to results of the sorting; and a transmitter/receiver that makes a first proxy acknowledgment for the packet stored in the storage unit and sends the first proxy acknowledgment to a source of the received packet, and that re-sends the packet to a destination of the received packet before a second acknowledgment for the packet is received from the destination of the received packet, wherein the sorting processor unit decides if the first proxy acknowledgment is required or not based on network bandwidth conformance flow identification results in the bandwidth controller if the second acknowledgment is not received within a specified time, and the transmitter/receiver makes the first proxy acknowledgment for the received packet when the sorting processor unit decides that the first proxy acknowledgment is required, and sends the first proxy acknowledgment to the source of the received packet before the second acknowledgment is received.