Stephen Balbach <stephen@clark.net> writes:

Routes the first packets and switches the rest based on "flows".

How is this conceptually different from cisco fastswitching wherein the slow path is used for the first packet towards a destination and all subsequent packets use a cache-based fast path? In both cases you have a slow cache-set-up path and a finite cache. There are significant disadvantages to using a cache in core routers (look up Dennis Ferguson's comments in your local NANOG archive, nobody I can think of can improve on them). The only principal advantage to cache-based routing is when you haven't got the power to process all packets through the same path without drops or mishandling of things like options and filters, but you do have the power to do some sort of hashed cache lookup. With luck, this will not be the case in future routers. Sean.