Cisco Technology, Inc.

Daniel Yu-Kwong Ng

Abhijit Patra

Nagaraj Bagepalli

Rina Panigrahy

Sanjay Jain

Jackie Liu

Yung-Chin Chen

Simon Wai-Ming Hsu

The present invention provides a packet processing device and method. A parsing processor provides instruction-driven content inspection of network packets at 10-Gbps and above with a parsing engine that executes parsing instructions. A flow state unit maintains statefulness of packet flows to allow content inspection across several related network packets. A state-graph unit traces state-graph nodes to keyword indications and/or parsing instructions. The parsing instructions can be derived from a high-level application to emulate user-friendly parsing logic. The parsing processor sends parsed packets to a network processor unit for further processing.

Programmable packet parsing processor

A method and apparatus wherein only a partial key is stored in a hashing table is disclosed. By storing a partial key as opposed to storing the entire original key, less data is required to be stored in the hash table. This reduces the attendant memory costs. The reduction in memory requirement does not degrade the hash functionalities whatsoever. Hashing conflicts can be fully resolved by consulting the partial key.

Partial key hashing memory

A method for sampling n-out-of-N packets in a network. Initially, the packet index corresponding to the N packets is pseudo-randomly shuffled. The shuffle function rearranges a set of numbers pseudo-randomly with a one-to-one mapping and no overlap. One way to perform the pseudo-random shuffle function is to use a linear feedback shift register (LFSR). The LFSR supports N being a power of two. However, the LFSR approach can be adapted to support N being any positive integer value. Based on the results of the shuffle function, sampling points are pseudo-randomly selected. By pseudo-randomly selecting the sample points, n-out-of-N sampling greatly minimizes biases.

Pseudo-random n-out-of-N packet sampling

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San Jose, CA, United States of America

Daniel Yu-Kwong Ng