Packet exchange device and packet exchange method

A packet exchange method at a packet exchange device which executes routing processing on a packet basis to transfer a packet in a packet communication network, wherein

• a first path unit of said packet exchange device outputs, to an output port having an output port number which is registered at a flow cache table and corresponds to a transmission source address and a transmission destination address of a received packet, said packet,
• said first path unit of said packet exchange device executes routing processing of determining an output port number for said packet, and
• said first path unit of said packet exchange device executes exception processing for said packet, and wherein
• when said output port number is not registered at said flow cache table, said first path unit transfers said packet to said middle path unit without outputting said packet to said output port, and
• when said packet from said first path unit is not a target of exception processing, said middle path unit executes said routing processing and when said packet is a target of exception processing, transfers said packet to said slow path unit.

A program executed on a packet exchange device which executes routing processing on a packet basis to transfer a packet in a packet communication network, comprising the functions of:

• a function of a first path unit of said packet exchange device to output, to an output port having an output port number which is registered at a flow cache table and corresponds to a transmission source address and a transmission destination address of a received packet, said packet,
• a function of said first path unit of said packet exchange device to execute routing processing of determining an output port number for said packet, and
• a function of said first path unit of said packet exchange device to execute exception processing for said packet, wherein
• when said output port number is not registered at said flow cache table, said first path unit executes said function of transferring said packet to said middle path unit without outputting said packet to said output port, and
• when said packet from said first path unit is not a target of exception processing, said middle path unit executes said routing processing and when said packet is a target of exception processing, executes said function of transferring said packet to said slow path unit.