Sometimes our technologies are more defined by the stories told about them than about their realities. SDN and NFV are no exceptions, and the full scope of mythology for either would take a lot more than a single article to cover. Fortunately we can narrow the scope of myths (and blogs) by focusing on what operators think are myths. I’ve culled through the views of service planners in the operator world and collected what they say are the SDN/NFV tales they think are the tallest.
Number one on all the lists is the myth of the five nines. We’d have SDN and NFV coming out our pores if we could only get them to five nines. Some operators think this is funny/silly and others think it’s destructive, but service planners agree it’s a myth. They make two critical points to validate their view.
First, the network business has for years demonstrated that buyers will trade off reliability for price, at least up to a point. According to the planners, the actual target for future services is only three nines, which is where their own research say buyers will draw the line.
Second, the notion that the nine-count for SDN or NFV is somehow holding up deployment is nonsense. The problem with both technologies is simply one of proving a business case, which in the service planners’ experience is mostly relating to proving a radical improvement in operations efficiency is possible. They don’t think SDN hardware is any less reliable than current network devices. They have not planned to replace major transport/connection devices with NFV functions. Counting nines isn’t the problem, it’s counting incremental return on investment.
The second myth the service planners listed seems to come out of frustration with some aspects of both SDN and NFV standardization. Call this one the myth of the perfect resource. According to this myth, we have to be able to define the resource needs of a given service with great precision. The greater the better, because if we could find that perfect match the service would be more profitable.
Wrong, say the planners. The fact is that “perfect routes” differ only a little in cost from imperfect ones, in the scope of services being considered for SDN. In NFV, a lot of attention to the precise resource needs of a given virtual function means that the effective size of the resource pool is much reduced, which means less economy of scale and more overprovisioning. A highly detailed assessment of deployment needs would also be more operationally complex to administer.
Myth number three is new revenue is going to come from shortening time to revenue. We hear all the time about service agility, but when you dig into the comments you find that the talker means “provisioning in hours rather than weeks”. That shortening is a limited benefit because most service delays are caused by access provisioning, which can be solved only by prepositioning capacity (and that can be done without either SDN or NFV).
The longest provisioning times today are for business data services, and these services tend to get provisioned when new sites are added. That happens relatively rarely; sites turn over at an average rate of less than 2% per year. In any event, planners say, you can’t necessarily run glass to every building hoping a customer will pop up there, and without access you can’t change provisioning times meaningfully.
The one area of exception to this is the area of feature hosting for add-on features like firewalls, NAT, DNS/DHCP, etc. which we’ve come to associate with virtual CPE. Planners admit that there’s likely a benefit to being able to sell users add-on connection features, but they also say that within a year or two nearly all connections have been equipped with the features they will need in the long term. Smart planners are asking what the cost of ownership will be when the dynamic period has passed.
The fourth myth service planners cite is controversial even among the planners. That one could be called the operations-business-as-usual myth. According to both SDN and NFV advocates within the operators’ business, SDN and NFV can be managed in the same way as the traditional devices could have been managed. No changes to either OSS/BSS or NMS practices will be required. Planners divide on this one, not based on whether there’s a myth here but based on why and how it would be dealt with.
A slight majority of planners believe that it is possible that “virtual device” management practices that made SDN or NFV look like traditional equipment could work. The problem for this group is that the qualifier is unacceptable because the consequences of being wrong would be truly dire. This group wants to see specific service trials to prove out the model, and they don’t see results they can bank on as yet.
The remainder of planners think it would be a waste of time to try to prove the point because it’s invalid on the face. An SDN enclave or a bunch of hosted functions are not traditional devices. Under the skin, they cannot be managed in the same way at all. SDN is not adaptive, it relies on setting failure modes and changing network configuration if something goes wrong. NFV substitutes servers and virtual connections for a physical appliance, and you have to manage what you really have not what it looks like or you’ll never fix anything.
One of the most interesting things that comes out of the service planner views isn’t their myth concept but the source of the myths. It’s become the norm to divide operators into three groups—Tiers One through Three. While the boundaries here are soft, they do roughly correlate with the SDN and NFV socialization that’s happening. The smaller an operator is, the more targeted the operator’s service set, the more likely it is that the operator has broadly socialized network technology changes and has hammered out an accommodation.
Service myths have the greatest impact on the Tier One operators, because those operators are the most likely to have largely independent standards and CTO processes that are budgeted and can go on for quite some time on their own, bereft of any broad support. Tier One planners say that a lot of the mythology of SDN and NFV comes not from the vendors but from their own people, who are looking to justify (to the rest of the company) a technology they’ve been advocating.
We’ve seen some pretty interesting NFV deployments from Tier Twos, and I think that the lesson of NFV mythology is that we’ll see the light in smaller operators first, ones who have better internal cooperation. The bigger ones should think about that one.
