Patent ID: 6430184
Filing Date: 2002-08-06
Classification: H04L

Abstract:
A method for creating, identifying, retrieving and storing the flow path switching information of a packet of information bytes comprising the steps of:(a) retrieving the header of the packet, (b) selecting a programmable subset of said header bytes, (c) hashing said subset to form a hash result, (d) second hashing of the header to form a signature value, (e) selecting portions of said hash result to form an index into a memory, (f) determining whether there is a valid flow tag at said index, (g) if there is no valid flow tag, then (g) (1) decoding the header of the packet to determine a forwarding flow path, (g) (2) creating a flow tag pointer for the packet, said flow tag pointer having a destination in a flow table, (g) (3) storing the flow tag pointer at said index, (g) (4) storing said signature value at said index, (g) (5) storing said forwarding flow path in said flow table at said flow tag pointer, and (g) (6) forwarding the packet, (h) if there is a valid flow tag, then (h) (1) comparing said signature value to a stored signature value at said index; and, (h) (2) if said signature value matches said stored signature value, following a stored flow tag pointer at said index to stored flow information in said flow table and forwarding the packet according to said stored flow information.