Patent ID: 7257590

Claim:
A method for classifying a binary string, comprising: searching for a plurality of classification fields for said binary string in respective search trees based on a matching procedure in which an index value is obtained in a leaf node of a respective search tree for each classification field found during said searching; deriving from index values obtained in said searching a policy configured to be applied to said binary string; reducing a number of index values by combining intermediate results of said searching or said deriving and mapping the number of index values onto one value by use of a knowledge of searches; incorporating said one value into said knowledge of searches to use said one value during a next search; storing an index value of a first classification field in a list attached to the leaf node of a second classification field, when a policy exists for a combination of the index values of said first and second classification fields; searching for said index value of said first classification field in said list attached to said leaf node of said second classification field when the search for said second classification field has reached said leaf node of said second classification field, deriving a classification for the binary string, and outputting the classification.