SDN is evolving out of its classic, capex-saving initial phase into more customer-facing applications and services, and cable operators are figuring out how to best leverage "SDN 2.0."

That was one of the takeaways from last week's Next Gen Technologies & Strategies conference at The Cable Center in Denver. During the "Virtualizing the Cable Architecture" panel, panelists were asked about the next use cases for SDN now that it is out of the hype phase.

Comcast's Nagesh Nandiraju, director, network architecture, said the industry has moved beyond terms such as "white box" and "merchant silicon" to "reality in some form or factor."

"We've been looking at different use cases," he said. "Pretty much every network function can be virtualized. Whether it makes make business sense, or makes technological sense, is where we're evaluating these different functions."

Figure 1: Question Master Light Reading's Carol Wilson poses a question to her panel at the Cable Next Gen Technologies & Services conference in Denver.

One of the key questions facing network operators is whether SDN capabilities are ready to deliver use cases beyond network resource management and be applied to customer-focused applications, such as virtualized CPE.

"It's still early stages of defining which one will come out first," Nandiraju said. "One of the things that we're very well invested in is using NETCONF/YANG models... The concept of delivering services in a programmatic way [is] one of the things that is already happening.”

Nandiraju said Comcast Corp. (Nasdaq: CMCSA, CMCSK) is also looking at both Layer 2 and Layer 3 VPN services using overlay networks. Nandiraju's Comcast colleagues are also examining IPv4-as-a-service in order to make the core network leaner for IPv6.

Michael Heffner, vice president product line management, Ensemble, at ADVA Optical Networking , said there is an increased focus on "getting more agility and efficiency" in delivering high-margin business services to companies of all sizes. "Whether you're virtualizing with white boxes, or merchant silicon, as you go to [DOCSIS] 3.1 there will be a lot of effort in terms of evolving the edge devices and the premises devices to support that. Why not take advantage of putting x86 merchant silicon out there as well so you can host virtual functions in addition to providing connectivity?"

He added: "You have also the option of virtualizing those capabilities in the cloud where it makes sense today. You could have some virtualization at the premises, while some can come back to the data center and central office."

Heffner said there are currently lots of brownfield application use cases around Layer 2 and Layer 3 VPNs, such as being able to inject virtual services in a Layer 3 VPN that is hosted in the cloud on a per-subscriber basis.

He added that ADVA's Ensemble operation (formerly Overture Networks) has had some discussions with cable operators on how virtualization can apply in the consumer space.

"There's a massive amount of investment out there," he said. "How can you do virtual DLNA [services] or virtual media centers? With media centers, you give them the ability to host their content in the cloud. [Customers] get access via their IP and smart devices in the home. There are a bunch of use cases for that."

Adam Grochowski, cable cloud architect at Juniper Networks Inc. (NYSE: JNPR), agreed with Heffner and Nandiraju about virtualizing CPE and adding services for subscribers, such as virtual firewalls. "But I think it's also traditional infrastructure as well, like customers' DVR services on infrastructure-as-a-service," said Grochowski. "Having an SDN controller and overlay brings all of those things together so you can create a more cohesive experience for your customers."

From the security end of the spectrum, Verimatrix Inc. President Steve Oetegenn said virtualization gives service providers the ability to pre-package security in the cloud with the delivery of content.

"We're seeing operators that are now starting to deploy cloud-based security services alongside piracy monitoring analytics capabilities," he said. "They combine OTT and traditional cable into one seamless offering to the customers."

Jeff Templeton, sales engineering director for NetScout Systems Inc. (Nasdaq: NTCT), agreed with the panel in regards to virtualized CPE for businesses. "That piece is accelerating quickly because there's opportunity, there's service velocity and you can turn things up quickly," Templeton said. "We've been working with them on virtualized applications where you can monitor and create KPIs [key performance indicators]."

For Templeton, the attraction of virtualization is a mix of potential cost savings and customer-centric service development. "I think there's a combination of both. I think the simple applications in the core are getting virtualized, but the more exciting ones are moving towards new services at the edge. You can virtualize your DNS and some of those applications in the core, but the more exciting ones are [related to] how you generate more revenue and new services with virtualized CPE."

— Mike Robuck, editor, Telco Transformation