Packet switching apparatus

A packet switching apparatus connected to a first network transferring packets using a first access method and a second network transferring packets using a second access method, said packet switching apparatus for forwarding packets received from a terminal connected to the first or second network to their destination based on a session as a point-to-point connection set up between the terminal and a destination network, the packet switching apparatus comprising:

• a plurality of input line interface units, each connecting to at least one input line and carrying out protocol processing in compliance with the OSI Reference Model, at least Layer 1, for packets input through said input line, the plurality of input line interface units including a first interface unit for receiving packets transferred from the first network using the first access method and a second interface unit for receiving packets transferred from the second network using the second access method, each received packet transferred from the first network providing route information including at least one of an input line on the first interface, an identifier of an input tunnel of the received packet, and an identifier of an input session of the received packet, each received packet transferred from the second network providing route information including at least one of an input line on the second interface, an identifier of an input tunnel of the received packet, and an identifier of an input session of the received packet;
• a plurality of output line interface units, each connecting to at least one output line and carrying out protocol processing in compliance with the OSI Reference Model, at least Layer 1, for packets to be output over said output line;
• a plurality of input session processing units, each connecting to at least a plurality of input line interface units and carrying out session or tunnel processing for packets received from the input line interface units;
• a plurality of output session processing units, each connecting to at least a plurality of output line interface units and carrying out session or tunnel processing for packets to be transferred to the output line interface units;
• a switch unit that carries out packet switching from the plurality of input session processing units to the plurality of output session processing units;
• a control unit connecting to said plurality of input line interface units, said plurality of output line interface units, said plurality of input session processing units, said plurality of output session processing units, and said switch unit and has control over them;
• a pathfinding table having corresponding information relating input information including at least each input line connected to the first interface and each input line connected to the second interface to associated output information for sending an output packet out from the packet switching apparatus toward the destination including an identifier of an output port of the plurality of output ports for outputting packets from the packet switching apparatus, an identifier of an output tunnel from the packet switching apparatus toward the destination for the output packet, including a bundle of a plurality of sessions through which packets are logically passed to a point in the destination network, and an identifier of an output session of the output packet;
• and
• a processing unit which, upon receiving a packet from the first or second network, searches said corresponding information to locate the output information corresponding to the input information specified by the route information included in the packet received, performs processing of the received packet, according to the output port, the output tunnel, and the output session located, and sends out the processed packet through the output port identified by the output port identifier of said corresponding output information to transmit the packet to a destination using the identifier of the output session and the identifier of the output tunnel.