It will be revolution by evolution as the new software and new hardware emerge in a chicken-and-egg dance.
The current 1.x versions of OpenFlow represent a compromise. “Ideally we would have started it as a generic match-and-action flow, but it had to be mapped on to existing chips—the next generation will be more protocol independent,” McKeown said.
Last year, the Open Networking Foundation (ONF) that oversees OpenFlow engaged ASIC makers in a so-called Forwarding Abstractions working group. It aimed to narrow the gulf between what OpenFlow wants to enable and what existing and planned ASIC do.
Now ONF is starting a new effort it calls a chip advisory board. “We will learn from them what’s possible [in silicon], and out of that will emerge what’s possible for the next generation of OpenFlow,” he said
OpenFlow began using content-addressable memories as an intermediary to interface to router and switch ASICs, but the approach limited its functionality. More recently it has used a technique of matching multiple tables.
“The protocol independent version [of OpenFlow] will take awhile,” McKeown said.