Patent ID: 6693908
Filing Date: 2004-02-17
Classification: H04L

Abstract:
A method of evaluating an incoming data packet at a network switch port, the method comprising:storing a plurality of templates for equations configured for identifying respective data formats, each template having at least one min term configured for comparing a corresponding prescribed value to a corresponding selected byte of the incoming data packet, storing header information associated with the min terms, the header information including effect min term fields and a plurality of equation identifiers, each effect min term field specifying which min terms are necessary for comparison with the corresponding selected byte, reading the effect min term to specify which of the min terms are necessary for comparison, simultaneously comparing, to the selected byte, the necessary min terms that correspond to the selected byte as the selected byte is received by the network switch port, identifying an obsolete equation which needs no further evaluation based on a comparison of the necessary min terms with the selected byte, storing, in a content addressable memory (CAM), the obsolete equation, and updating the effect min term fields based on the obsolete equation specified in the CAM.