Patent ID: 8339950

Claim:
A router, comprising: a first cache configured to store flow information of received packets each time a packet is received in a queue; a second cache configured to store flow information of received packets if a number of the received packets in the queue exceeds a rising threshold; and a packet processor to discard a received packet by applying a high drop probability if flow information of the received packet is stored in the second cache and if the number of the received packets in the queue exceeds the rising threshold, and the packet processor to update the second cache by storing the flow information of the received packet in the second cache if the second cache is not full and if the number of packets in the queue exceeds the rising threshold, wherein the flow information comprises: IP address and port number associated with the received packet; and a hit count of the received packet having the IP address and the port number, wherein if the second cache is full and if the number of the received packets in the queue exceeds the rising threshold, the packet processor deletes a flow information stored in the second cache, which has a hit count smaller than a hit count of the received packet and then stores the flow information of the received packet in the second cache, and wherein the packet processor discards the received packet by applying a low drop probability if the flow information of the received packet is not stored in the second cache and if the number of the received packets in the queue exceeds the rising threshold.