Flow identifying device, flow processing device, flow identifying method, and flow processing method

A flow processing device comprising:

• a receiving section for extracting an input logical link number from received data and terminating said received data and creating a received IP packet;
• a packet receiving and processing section for extracting each field of a header as a retrieval key from said received IP packet and extracting a destination address and outputting a packet;
• a retrieval flag table for storing said input logical link number and a retrieval flag in a correspondence relationship, said retrieval flag setting a field to be retrieved among fields of the header of said received IP packet, and for outputting a retrieval flag corresponding to an input logical link number extracted by said receiving section;
• a mask section for masking each field of a header of a received IP packet with said retrieval flag and creating a post-mask retrieval key;
• a flow retrieval table for storing a post-mask key and a flow retrieval as a flow identification result in a correspondence relationship and outputting a flow retrieval corresponding to a post-mask retrieval key output from said mask section, said flow retrieval table being formed of a content-addressable memory;
• a forwarding table for storing a destination address of a header of said received IP packet and a forwarding retrieval in a correspondence relationship and outputting a forwarding retrieval corresponding to a destination address output from said packet receiving and processing section;
• a flow action table for storing a group of said flow retrieval and said forwarding retrieval and flow action information having information setting QoS (quality of services) and an output logical link number in a correspondence relationship and for outputting flow action information and an output logical link number, corresponding to a group of a flow retrieval output from said flow retrieval table and a forwarding retrieval output from said forwarding table;
• a packet transmission and processing section for processing a packet output from said packet receiving and processing section based on flow action information output from said flow action table and for creating a transmission IP packet;
• and
• a transmission section for disassembling said transmission IP packet to create a transmission cell and transmitting said transmission cell to an address indicating an output logical link number output from said flow action table.

A flow identification method comprising the steps of:

• retrieving a retrieval flag corresponding to an input logical link number extracted from received data from a retrieval flag table, said retrieval flag table storing an input logical link number of received data and a retrieval flag setting a field to be retrieved among fields of a header of a received IP packet terminating said received data;
• creating a post-mask retrieval key in a mask section by masking each field of a header of said IP packet with said retrieval flag;
• and
• storing a post-mask retrieval key and a flow identification result in a correspondence relationship and outputting a flow identification result corresponding to a post-mask retrieval key output from said mask section from a flow retrieval table, said flow retrieval table being configured of a content-addressable memory.

A flow processing method comprising the steps of:

• extracting an input logical link number from received data and terminating said received data and creating a received IP packet;
• extracting each field of a header as a retrieval key from said received IP packet while extracting a destination address;
• retrieving a retrieval flag corresponding to an input logical link number extracted from received data from a retrieval flag table, said retrieval flag table storing said input logical link number and a retrieval flag setting afield to be retrieved among fields of a header of said received IP packet in a correspondence relationship;
• creating a post-mask retrieval key in a mask section by masking each field of a header of a received IP packet with said retrieval flag;
• storing a post-mask retrieval key and a flow retrieval as a flow identification result including information for setting QoS (quality of services) in a correspondence relationship and retrieving a flow retrieval corresponding to a post-mask retrieval key output from said mask section from a flow retrieval table, said retrieval table being configured of a content-addressable memory;
• retrieving a forwarding index corresponding to a destination address extracted from a received IP packet from a forwarding table, said forwarding table storing a destination address of a header of said received IP packet and a forwarding index in a correspondence relationship;
• retrieving flow action information and an output logical link number, corresponding to a group of a flow index retrieved with said flow retrieval table and corresponding to a forwarding index output with reference to a flow action table, said flow action table storing a group of said flow index and said forwarding index and flow action information including indication information setting QoS and an output logical link number, in a correspondence relationship;
• processing said received IP packet based on flow action information output from said flow action table to create a transmission IP packet;
• and
• creating transmission data based on said transmission IP packet and transmitting said transmission data to a destination indicating an output logical link number output from said flow action table.