| 摘要 |
In accordance with a method and apparatus for classifying data packets, a packet classification architecture includes a cached hash table that stores a subset of classification identifiers (i.e. classIDs) for a plurality of data flows. A forwarding engine coupled to the cache receives packets and first attempts to classify the packet by generating a hash key based on header information from the packet and using the hash key to lookup a corresponding entry in the hash table. A hash caching policy according to the invention aims at maintaining high, classification speeds by (1) employing a hash function that evenly distributes hash key indexes, thus reducing the likelihood of collisions and by (2) employing a hash removal scheme that uses Internet traffic statistics and characteristics to improve the likelihood that hash entries corresponding to statistically important flows will remain cached.
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