Patent ID: 7773600

Claim:
A packet forwarding device for performing forward control on a packet received from one of a plurality of input ports based on forward control information predefined for a packet flow to which the packet belongs and transmitting the packet from one of a plurality of output ports specified by header information of the packet, the packet forwarding device comprising: a flow classifier for classifying the packet received from the one of the plurality of input ports into a packet flow to which the packet belongs, according to the header information of the packet; wherein the flow classifier includes: a flow Content Addressable Memory (CAM) comprising a plurality of memory regions corresponding to formats of search keys, each of said memory regions including a plurality of flow entries each including a plurality of information fields for indicating values of header information items to constitute a flow condition and excluding information fields corresponding to header information item unnecessary for the flow condition, wherein each of said search keys includes at least one header information item selectively extracted from the header information of the packet depending on the flow condition of the packet and the flow entries in said flow CAM as compared with the search key so that an address of one of the flow entries matched with the search key and outputted from the flow CAM is used to specify the forward control information to be applied to the packet.