10. An apparatus for packet classification comprising: a memory for storing a hash table provided with rules for the packet classification; a tuple generator for determining a matching length of how long each field value of one or more fields in an input packet coincides with a field value of a corresponding field stored in a rule set by performing a field-by-field search on the fields in the input packet, generating a tuple list made up of a combination of one or more of the matching length for the respective fields, and selecting particular tuples existing in the rule set from the tuple list; and a packet classifying control for filtering each of the particular tuples selected by the tuple generator by using a Bloom filter to produce positive tuples, and searching for a best matching rule for the input packet by accessing the hash table based on a search pool including exclusively the positive tuples resulting from the filtering.
18. The apparatus for packet classification in claim 10 , wherein the one or more fields are source port number field and destination port number field.