Packet routing apparatus and a method of routing a packet

A routing apparatus provided with a plurality of ports, for transmitting a packet received from one of the ports to another port, comprising:

• one or plural routing units connected to at least one port, for routing the packet received from the at least one port to the other port;
• a coupling unit for mutually connecting the respective routing units;
• and
• at least one function unit connected to the coupling unit, which receives the packet from the respective routing units, executes a predetermined processing for the packet, and transmits the packet to the respective routing units;
• wherein each of the routing units comprises:
• a reception unit for receiving the packet from the at least one port;
• an addition unit for adding an identifier to a head portion of the packet;
• a first lookup unit which uses first information contained in the packet to acquire first route information corresponding to a destination routing unit, and stores the first route information into the identifier;
• a second lookup unit which uses second information contained in the packet to judge whether the packet should be transmitted to the function unit, acquires second route information corresponding to the function unit in a case where the packet should be transmitted to the function unit, and stores the second route information into the identifier;
• a storage unit for storing the plurality of pieces of first route information corresponding to the respective routing units and the at least one piece of the second route information corresponding to the function unit;
• a relay unit for transmitting the packet added with the identifier to the coupling unit and receiving the packet from the coupling unit in accordance with the first route information contained in the identifier;
• and
• a transmission unit for transmitting the packet to one of the ports in accordance with the first route information contained in the identifier.

A router provided with a plurality of ports, for routing a packet received from each of the ports to another port, comprising:

• a plurality of routing modules connected to at least one port, for mutually transmitting a packet received from the at least one port;
• a transmission unit for connecting the respective routing modules to each other and transmitting the packet;
• and
• at least one function module connected to the transmission unit, which receives the packet from the transmission unit, executes a predetermined processing for the packet, and transmits the packet to the transmission unit;
• wherein each of the routing modules receives the packet from the at least one port, uses header information contained in the packet to judge whether the packet should be transmitted to the function module, adds a first label to the packet in a case where the packet should be transmitted to the function module, adds a second label to the packet in a case where the packet is not transmitted to the function module, and transmits the packet to the transmission unit.