Packet transferring method and apparatus that employs the same
Every router in a network is provided with flow detecting means that detects a flow from a packet header of a packet so as to perform such packet processings as bandwidth monitoring, priority-based transferring, statistical information collecting with respect to each packet flow. Receiving a packet from a site, an edge router detects the packet flow and writes a flow identifier in the packet. Each flow identifier is uniquely decided in the network. The Internet router performs such packet processings as bandwidth monitoring, priority-based transferring, statistical information collecting with respect to each flow according to the flow identifier. The present invention can thus prevent the network from degradation of transferring performance caused by the flow detecting means of a backbone router.
1. A packet transferring apparatus that outputs an inputted packet to any one of a plurality of output lines and is connected to a node, the apparatus comprising:
a flow detecting unit for deciding a flow ID that is an identifier of a flow bundle to which the inputted packet belongs according to information written in a header of the packet; and
a packet transmitting unit for adding the decided flow ID to the packet and sending the packet to the node, wherein
the node comprises a flow processing unit for performing at least one of packet processings including bandwidth monitoring, statistical information collecting, filtering, and priority-based transferring according to the flow ID,
wherein the flow detecting unit includes
a contents addressable memory having a plurality of flow entries, each including information written in a packet header, the memory being configured to determine a matching/unmatching between the header information of each inputted packet and each of the plurality of flow entries so as to output matching addresses which are addresses of matched flow entries; and
an address translating unit for translating a plurality of the matching addresses to one flow ID.
2. The packet transferring apparatus according to claim 1 , wherein the address translating unit includes:
an address translation table that stores a flow ID for each of the matching addresses; and
an address translation table controlling means for inputting each of the matching addresses as an address for reading the flow ID from the address translation table.
3. The packet transferring apparatus according to claim 1 , wherein each packet is decided with one unique flow ID.
4. The packet transferring apparatus according to claim 1 , wherein the flow detecting unit includes means for deciding a new flow ID according to the flow ID written in the header of the inputted packet so as to identify the new flow ID that is the identifier of the flow bundle to which the inputted packet belongs to write the new flow ID in the header.
5. The packet transferring apparatus according to claim 1 , wherein the node performs said at least one packet processing on all packets that belongs to the flow bundle collectively.
6. The packet transferring apparatus according to claim 4 , wherein the new flow ID is decided by the flow ID in conjunction with source site information included in the header of the inputted packet.
7. The packet transferring apparatus according to claim 4 , wherein each packet is decided with one unique new flow ID.