Patent ID: 7457292
Filing Date: 2008-11-25
Classification: H04L

Abstract:
1. A packet identification device for identifying contents of an input packet, comprising: a lookup table that stores a plurality of reference data each divided into unit data associated with respective attributes, in a distributed manner in respective storage areas having addresses defined on an attribute-by-attribute basis, and is operable when a reading address is input, to output a plurality of unit data associated with one of the attributes corresponding to the reading address; an analysis circuit that analyzes an attribute of a comparison data item in the input packet; an address control circuit that outputs an address corresponding to the attribute of the comparison data item analyzed by said analysis circuit to said lookup table, as the reading address; and a plurality of unit comparison circuits provided in association with the plurality of reference data, respectively, for each performing comparison between an associated one of the plurality of unit data output from said lookup table and the comparison data item analyzed by said analysis circuit, wherein: when all of comparison data items extracted from the packet match respective unit data of same attributes in the reference data, said unit comparison circuit determines that there is a match between the reference data associated therewith and the packet, said lookup table stores the reference data including comparison result data to be output as the result of comparison, said address control circuit outputs an address of a storage area storing the comparison result data to said lookup table after completion of comparison of all of the comparison data items in the packet, and said unit comparison circuit outputs the comparison result data delivered from said lookup table, as the result of comparison, when there is a match between the reference data associated with said unit comparison circuit and the packet.