What might OpenFlow actually open up?

A few weeks ago, I attended the PacketPushers webinar on OpenFlow – a networking technology that, while not seeing widespread adoption as yet, is still creating a buzz on the networking scene.

It certainly busted a lot of myths and misconceptions folks in the audience may have had about OpenFlow, but the big questions it left me with are what OpenFlow stands to open up, and what effect it might have on many well established vendors who currently depend on selling “complete” pieces of networking hardware and software – the classic router, switch or firewall as we know it.

If I think back to my annoyances back in the early 2000’s it was of the amount of feature bloat creeping into network devices, while we still tended to have a lot of monolithic operating systems in use, so a bug in a feature that wasn’t even in use could crash the device, because the code would be running, even if it wasn’t in use. I was annoyed because there was nothing I could do other than apply kludgy workarounds, and nag the vendors to ship patched code. I couldn’t decide to rip that bit of code out and replace it with some fixed code myself. When the vendors finally shipped fixed code, it was a reboot to install it. I didn’t much like being so dependant on a vendor, as not working for an MCI or UUnet (remember, we’re talking early 1999-2001 here, they are the big guys), at times my voice in the “fix this bug” queue would be a little mouse squeak to their lion’s roar, in spite of heading up a high-profile Internet Exchange.

Eventually, we got proper multi-threaded and modular OS in networking hardware, but I remember asking for “fast, mostly stupid” network hardware a lot back then. No “boiling the sea”, an oft-heard cliché these days.

The other thing I often wished I could do was have hardware vendor A’s forwarding hardware because it rocked, but use vendor B’s routing engine, as vendor A’s was unstable or feature incomplete, or vendor B’s just had a better config language or features I wanted/needed.

So, in theory, OpenFlow could stand to enable network builders to do the sorts of things I describe above – allowing “mix-and-match” of “stuff that does what I want”.

This could stand to threaten the established “classic” vendors who have built their business around hardware/software pairings. So, how do they approach this? Fingers-in-ears “la, la, la, we can’t hear you”? Or embrace it?

You should, in theory, and with the right interface/shim/API/magic in your OpenFlow controller, be able to plug in whatever bits you like to run the control protocols and be the “brains” of your OpenFlow network.

So, using the “I like Vendor A’s hardware, but Vendor B’s foo implementation” example, a lot of people like the feature support and predictability of the routing code from folks such as Cisco and Juniper, but find they have different hardware needs (or a smaller budget), and choose a Brocade box.

Given that so much merchant silicon is going into network gear these days, the software is now the main ingredient in the “secret sauce”, the sort approach that folks such as Arista are taking.

In the case of a Cisco, their “secret sauce” is their industry standard routing engine. Are they enlightened enough to develop a version of their routing engine which can run in an OpenFlow controller environment? I’m not talking about opening the code up, but as a “black box” with appropriate magic wrapped around it to make it work with other folks’ controllers and silicon.

Could unpackaging these crown jewels be key to long term survival?