Method and apparatus for classifying Internet Protocol data packets

A method of classifying an Internet protocol packet in a data structure, comprising:

• deriving a first hash key from the packet, by using a first hashing data for obtaining a second hashing data and a pointer from an entry in a level-1 table;
• deriving a second hash key from the packet, by using the second hashing data for designating a hash bin in a level-2 table designated by the pointer;
• and
• obtaining from said hash bin a rule suitable for the packet and processing the packet according to a flow identifier associated with the suitable rule.

A method of associating an initial key to a bin in a level-2 table, comprising:

• hashing the initial key to generate an intermediate key;
• applying a first hashing data to said intermediate key to generate a first hash key for designating an entry of a level-1 table that contains a second hashing data and a pointer;
• and
• applying said second hashing data to said intermediate key to generate a second hash key for designating a bin in a level-2 table designated by the pointer.

An apparatus for generating a data structure and classifying a received Internet Protocol packet by using said data structure, comprising:

• a network processor coupled to a direct memory access engine and comprising a local memory, said network processor being adapted to classify an Internet Protocol packet;
• a control processor adapted to couple to an external memory system, and to generate and update a classification data structure by:
• (1) populating an entry of a level-1 table, which is designated by a first hash key derived from a classification rule by using a first hashing data, with a pointer to a level-2 table and a second hashing data;
• and
• (2) populating a bin in said level-2 table with the classification rule, the bin being designated by a second hash key derived from the classification rule by using said second hashing data;
• wherein said control processor stores said level-1 table in said local memory and said level-2 table in said external memory system.