Abstract: As Internet packet flow increases, the demand for high speed packet filtering has grown. The present invention introduces several methods for a high-speed rule processing. The methods are geared towards Internet Protocol (IP) packet processing.

Abstract: A method and apparatus for performing network address translation is disclosed. The method generates statistically unique port number for each outgoing connection. The statistically unique port numbers are formed from a subset of bits from the source node's IP address and a subset of bits from the port number assigned by the source node. The statistically unique port number is used as an index into a table containing connection information. When a statistically unique port number fails to be absolutely unique, the method uses a secondary fallback system that generates a unique port number by using sequential numbering system. The information about the connections using unique port numbers that were generated sequentially is stored in a secondary connection table. The secondary connection table is organized as a Patricia tree.