Patent ID: 6633565
Filing Date: 2003-10-14
Classification: H04L

Abstract:
A method of switching data utilize tags for use in a network device, said method comprising the steps of:providing a tag assignment cache for storing previously received flows and tags corresponding thereto; determining a current flow from a header portion of a received frame and comparing said current flow with recently received flows stored in said tag assignment cache; if a match is found, reading a tag from said tag assignment cache corresponding to said current flow, and if a match is not found randomly choosing a tag from a pool of unused tags and associating it with said current flow and storing said current flow and said tag in said tag assignment cache; in the event no unused tags are available, selecting a tag for reuse and setting a new-tag-bit in the received frame only for the first frame of said current flow: appending said tag to said received frame; providing a tag forwarding cache for storing forwarding decisions and corresponding tags; for each new flow received, calculating a forwarding decision and substitute header and storing the results of said forwarding decision, substitute header and the tag associated therewith in said tag forwarding cache; for frames of a flow other than the first, retrieving a forwarding decision and substitute header from said tag forwarding cache based on the tag appended to said received frame; applying said forwarding decision and substitute header to said received frame to produce an output frame; and forwarding said output frame with said substitute header to the appropriate output port in accordance with the forwarding decision corresponding thereto.