Packet filtering for data networks
AssigneeGrand Junction Networks, Inc.
InventorsRichard J. Hausman, Lazar Birenbaum
Life of this patent
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Abstract
An improved partial packet filter (10) for filtering data packets (210) in a computer network (12) wherein a candidate field (413) of the data packet (210) is hashed to a plurality of bit-wise subsets (636) each being an independent representation of the candidate field (413). Each of the bit-wise subsets (636) is compared to a reference hash table (644) which has been prepared in a preliminary operation series (514). The preliminary operation series (512) configures a plurality of target fields (714) to set selected memory locations (312) in the reference hash table (644).
Claims17
A method for selectively forwarding a data packet and controlling the distribution of data packets in a computer network system, the data packet having a candidate field containing information about the data packet, the method comprising:
- configuring a target memory of a controller to contain a target hash array in steps including;
- aa determining a target field and extracting a plurality of target indices from said target field, the target indices being a binary number having a value;
- ab setting memory locations in the target memory corresponding to the value of each of the target indices;
- and
- processing the data packet in steps including:
- ba extracting the candidate field from the data packet;
- bb extracting from the candidate field a plurality of candidate field indices;
- bc comparing the values of each of the candidate field indices to the target hash array;
- and
- bd forwarding the packet when each of the values of each of the candidate field indices corresponds to a memory location of the target hash array which was set in step ab.
Dependencies are inferred from the claim text.