What will SDN and NFV be when they grow up? That’s a question we often ask children, but infant technologies ought to be prepared to answer it too. Kids don’t find answering easy nor do they get it right often, and it may be that technologies don’t do any better.
If you define what you are by consensus, then SDN and NFV are doing pretty well. In almost all the surveys, people think they’re revolutionary by more than a 2:1 margin. Fully a third of businesses say they already have SDN (but roughly that same percentage say they have terabit Ethernet and almost that many think they’re descended from royalty). Nearly all the Tier One operators say that NFV plans are well advanced, nearly all network vendors say they can deliver on NFV and SDN right now. Hey, the war’s over folks. Go home.
Where we really are, according to survey results I’ve gotten so far this fall, is a lot less inspiring. SDN has no significant traction outside the data center, and even in the data center the rate of adoption (versus tire-kicking) is less than 2%, which is below statistical significance for my surveys. NFV? Your chances of having it are less than being struck by lightning.
If instead of looking to others for definition we look to formalism, we also get some interesting results. There are now published references or specifications for both SDN and NFV. About half of users say that SDN is fully standardized, and about a quarter say that NFV is. Neither is, of course, and the first specifications for NFV became public only last week. Some insiders in the SDN space told me that there were more standards to be done than there were already completed, and I believe it.
Where are really, though? Or isn’t there any reality to measure? I think that there is an objective state to both SDN and NFV but I don’t think that the current state of either gives us much of a hint as to where the mature version of either technology might go.
We have two issues with our two revolutions. First, both of them are aimed primarily at improving costs and not improving services. Revolutionary cost reduction approaches are kind of oxymoronic because revolution generates enormous risk and buyers apply enormous risk penalties that would make savings very difficult to validate. We would therefore be forced to accept the cost-reducing paradigm as the driver of our technologies, or accept that they are revolutionary, but not both. Second, both of them suffer from what could be called a “lack of holism”.
How much could SDN or NFV save? Buyers say that both are likely to generate a 20% reduction in capital cost (so far; the survey results aren’t all in). How much of that savings would be offset by increased operations costs? The estimates vary from half to levels of opex growth that would be more than 1.5 times the capex savings. Nearly every buyer says that they could accept such savings absent significant adoption risk but remember that most think there is such a risk. You can’t help but recognize that both SDN and NFV stand or fall not on their capex reduction but on their ability to cap or even lower opex.
Which is where our second point comes in. SDN is so far a kind of point technology. You can do itty bitty pockets of SDN or you can do SDN at a thin boundary in your stack, but you can’t to reeeeeallllly big SDN. Most vendors target SDN at the data center only, and most buyers say that their network costs are not even 50% focused in the data center. Further, buyers can’t identify specific equipment from specific sources that would address SDN in a broader context, which means that they don’t see SDN as a replacement for current network equipment in a general sense.
NFV is similarly contained. The specifications for NFV acknowledge an end-to-end service but also acknowledge that parts of it are likely to be outside the domain of hosted virtual functions. That would mean every NFV service is a hybrid of current and NFV technology elements, but how that fusion is created and managed isn’t clear. Would we automate the deployment of virtual functions and fall back to legacy practices to build the non-NFV pieces? Would we manage one piece of a service using NFV principles and the rest based legacy? In fact, could we harmonize NFV management with current operations practices at all?
SDNCentral defines SDN, NFV, and NV with the latter meaning “network virtualization” and I think there’s merit in this. The real transition here is to the notion of as-a-service networking where the “service” is created by something other than a tinker-toy assembly of fixed devices. By, in short virtualization. We need to be thinking about how we’d build a network if we didn’t have device constraints, not thinking about how we’d replicate current devices by creating virtual versions of them. How can we hope to optimize absent an agile service vision to match the agility of our revolutionary technologies?
I’m hoping to see how some of these issues are addressed by the vendors and operators at the SDN World Congress this week. I’ll keep you posted on whether I’m pleased or disappointed.