Software-Defined Networking has taken the world by storm – if by “world,” we mean telcos, service providers, cloud data centers, backhaul carriers and, of course, equipment vendors.

While most of the rest of the IT world is still grasping with understanding what SDN is, and how to leverage SDN across real and virtual networks, a new acronym has emerged: NFV.

Network Functions Virtualization, defined simply, means talking about abstracting the services provided in traditional network appliance hardware, like routers, load balancers, intrusion detection systems and firewalls, and implementing those services, directly on a network through software.

An interview with a number of leading technology analysts, service providers, equipment makers and platform vendors has revealed the strengths and benefits of SDN and NFV – and also the challenges that customers may face when implementing these new technologies.

“We're in the very early days of NFV. There's going to be a long process,” said Shin Umeda, Vice President with the Dell’Oro Group, a market research firm.

“We're going to see vendors, we're going to see service providers, spending a lot of money and a lot of time trying to figure out what to do. One of the challenges that we all face in this industry is how do we keep this moving?”

Testing and quality assurance are key, according to Bob Mandeville, president of Iometrix, which certified network equipment against standards like CE 2.0, the standard for Carrier Ethernet from the MEF (Metro Ethernet Forum).

“I'll just start by saying very briefly that the MEF has seen testing play a role in bringing Carrier Ethernet to the marketplace and speeding up the adoption in a very significant way through the MEF Certification Program,” said Mandeville.

“There is a sister organization that has been created, the CloudEthernet Forum [CEF], and its focus is the definition -- much like the MEF -- of services, but this time of cloud services” like those defined by NFV, he continued.

Definitions for network services are essential, and NFV is a big part of those definitions, agreed Viral Vimawala, Architect for Virtualization Solutions for test company Spirent Communications.

“There are four aspects, predictability, availability, scale and security, everything that we've been talking about in terms of NFV,” he said, and everything rolls down to those four aspects.

Vimawala continued, “We are talking about interoperability -- there are servers which are virtualized. There are networks, they are being virtualized. What does it mean? Is it the same thing?

"Not really, because these virtualized network functions, are going to be residing on the server which is virtualized, so now your problem became twofold. And that's where the biggest question mark is.”

The questions don’t have to be too difficult to answer around SDN and NFV, says Arpit Joshipura, Vice President at Dell Networks.

“SDN was hard to grasp two years ago. NFV is not hard to grasp because it is a one-line explanation. When you do voice, video, data on your carrier network today, there are about 16 boxes, purpose built, that make that happen.

"We need to move most of those purpose-built boxes to general purpose, what he's showing as NFVI, network function virtualization infrastructure, meaning general-purpose server storage compute,” he said.

“The challenge is to make sure that,” Joshipura added, “as these purpose-built boxes move to general-purpose infrastructure, we are using the same building blocks that have been proven now in the SDN world, server storage compute, orchestration, SDN orchestration, overlay, underlay, OpenFlow, doesn't matter. Use those building blocks and then write the functions on top.” And that’s NFV.

Don McCullough, Director of Strategic Communications for equipment maker Ericsson, insists that the move to NFV is more than technical. “There is a transformation going on. I think it's important to recognize that it's as much a cultural transformation as a technological transformation,” he said.

“It's about changing the culture from selling things that the carrier has to selling and being part of the enterprise tasks. How can network storage compute help different enterprise tasks instead of selling generic products?

"And on the operations side, it's going from a manual process-driven solution to something much more flexible, automated.”

“If you look down into the NFV or SDN, you'll see that these technological things tie back to these cultural changes,” explained McCollough.

“That's all about charging for these new services, and it's all about automating out this OPEX. So I think it's really important to understand that this is as much a cultural change in the carriers globally as it is a technological change in the networks that they run.”

The theme was picked up and amplified by Mike Capuano, Vice President at Infinera, which makes high-capacity optical equipment for service providers.

“Taking the carrier view is the right way to look at it. In addition to focusing on being part of the enterprise service delivery capability, service providers have to scale their networks, and all these boxes that Arpit mentioned cost a lot of money, more bandwidth, more boxes, every box doing a specific function.”

Capuano added, “The ability to kind of take those boxes and write software that just runs on an x86 server can allow that ability to scale more quickly and rip a lot of costs out of the network, which is what they need to do.

"And what we're hearing from carriers, like for example Telefonica, who presented on this recently, is they're looking at taking this as far as they can. And the lines between NFV and SDN sort of blur, because they're saying, hey, I'm not just going to NFV something like a firewall or NFV an evolved packet core. I want to NFV the edge router.

"I want to NFV the B-RAS and get to this place where we've got an optical connection between sites in the metro, an optical connection between cities in the core, and around that we have x86 servers or perhaps white-box switches with software running in the cloud and software running in those servers to deliver the most cost-efficient network possible that can also scale and be flexible.”

That type of scalability is one part of NFV – but only one part, said Doug Wills from Juniper Networks. “One of the big drivers for NFV is about scaling the network, and the other piece to it is just reducing complexity.

To give everyone a picture of what a tier-one carrier network looks like, in addition to routers and switches there are really thousands of special-purpose devices that are just set up to do one thing.”

“What we get constantly back at Juniper as a provider of telco infrastructure and cable infrastructure is, guys, can you do anything to reduce complexity? Because with more complexity, it becomes an OpEx thing, it becomes a CapEx thing. And, frankly, as telcos push into cloud services, this is where the scaling issue becomes a real challenge,” Wills said.

“Carriers, when they look at cloud and they think about providing a cloud infrastructure, either for themselves or for their customers and look at their web service providers, they're saying, hey, these guys are just inherently more efficient and smarter about their network infrastructure. And for us to be competitive in this cloud future, we need to get there,” continued Wills.

“NFV is going to be a big driver for carriers to basically take these dedicated hardware devices that provide layer four through layer seven services and run them on a server. And that will at least put them on a competitive footing with some of these large web service providers.”

Being competitive means more than being a low-cost provider; it also means offering new and unique capabilities to customers. Steve West, CTO of Cyan, which makes an SDN orchestration platform, explained, “What's interesting is NFV, when it was initially positioned, was a cost reduction. It was about taking cost and complexity out of the carrier network.

"When we talk to carriers today, the perspective has broadened. It's not only how do you reduce costs, but how do you also enable revenue? And I hear from some of the carriers that they need both to make the case work. The business case actually requires both.”

“From a business model perspective, one of the biggest challenges that the whole value chain is faced with,” West continued, “is that the business model normally in our industry is around finding some differentiated and defensible position that you can then build on and defend through incremental improvement on that position that you've adopted.”

West explained that the transition to SDN and NFV involves opening up and being open to collaboration with others. “When you have that view of closing things down and defending your business by being closed, this kind of transition is actually quite tough,” he said.

Martìn Casado, CTO, Networking, VMware comments “I think people view SDN and network virtualisation as this existential threat, this thing that's coming and whatever. But largely it's here. We've got the use cases, we've got the proof points.

"And so what's been interesting to me is to watch the evolution of the use of this. You're starting off in provisioning, you're starting off with a simple use case, but more and more, it's become security, actually, that's driving a lot of sales of this.”

Dell’Oro’s Umeda agreed. “In describing or defining NFV, this is a movement that's being driven by the end user, the service providers, and it's not something that some vendor came up with from a technology standpoint and pushing it out into the market and driving demand from that perspective.

So this is really a different approach or different force that is leading this movement, and so I think, as Steve points out, there are numerous incentives for the operators to take on this challenge, so I think that in itself is a great positive for this overall movement of NFV.

"That's something we can take to heart.”

By Alan Zeichick