Editor's Note: With ETSI NFV ISG meeting #4 happening this week in Sunnyvale, Calif., we wanted to bring in a new perspective from the cable operators. We are fortunate to have Chris Donley of CableLabs join us for this fourth installment of our NFV interview series. Be sure to check out our previous interviews in the series, with  Eric Carmès of 6WIND, Margaret Chiosi of AT&T, and Christos Kolias of Orange. And we have more coming!

Chris Donley serves as director of advanced networks and applications at CableLabs. Mr. Donley is leading CableLabs’ research efforts on Software Defined Networking (SDN), Network Functions Virtualization (NFV), Metro Ethernet, and home networking. He has been with CableLabs for seven years. Mr. Donley received a Bachelor's degree in Engineering from Dartmouth College and a Master's degree in Business Administration from the University of Colorado. He holds Cisco CCIE and (ISC)2 CISSP certifications, and has been granted four U.S. patents.

Can you explain the role of CableLabs in the industry?

Donley:  CableLabs is a non-profit R&D consortium supporting the cable industry.  We aim to create new technologies and help our 49 member cable operators integrate them into their businesses.  In this role, we work with our members and technology suppliers to experiment with and build consensus on approaches to emerging technologies.

Many of the founding members of the NFV initiative are non-cable operators. Do you believe NFV is just as relevant to the MSOs, and why?

Donley:  Yes, NFV is relevant to cable operators for many of the same reasons it’s relevant to other service providers.  It offers more flexibility in how equipment is deployed in the network, and faster time-to-market for new services.  CableLabs is a member of [the NFV ISG], and we’ve been looking at the use cases and architecture under development.  Outside of a few areas that are access-network-specific (e.g., for DSL), the use cases also fit cable networks very well.

Are there any differences in the cable business versus, say, a Verizon or AT&T?

Donley:  I’d say that the major differences are in the access network.  Our members typically use Docsis, not DSL, so some of the equipment at the edge is different. Compared to PON architectures, sometimes the main difference is 100 feet of coaxial cable from the node to the side of the house.  Network cores look very similar between North American MSOs and Verizon or AT&T, both from an architectural and equipment perspective.

What's your take on SDN and NFV — how do they play together?

Donley:  To oversimplify a bit, NFV provides the "what" and SDN provides the "how." Let’s take the example of a firewall. If we virtualize it using NFV and run it in a VM on a cloud server, we probably don’t want to route all the subscriber traffic through that VM. Instead, we might want to push the firewall rules down to elements in the forwarding path using SDN techniques.  One of the axioms in security is to filter traffic as close to the source as possible; with this new SDN/NFV firewall, we can now enter rules through a single UI and push them to both edges of the network, instead of only one side, as with a traditional firewall.

In your mind, do SDN and NFV create new services for you, help reduce opex or help reduce capex?

Donley:  The primary driver is opex reduction.  By adding SDN and NFV to the network, we can take advantage of DevOps methodologies and tools such as Puppet and Chef to improve device provisioning, increase automation, and reduce errors. Once SDN and NFV are available in the network, I think the next priority is new service creation.  These platforms allow us to reduce the current waterfall development cycles and adopt newer agile/lean startup methodologies to shorten development intervals.

Based on what you know, where are MSOs today in terms of SDN and NFV deployment? For example, Comcast was an investor in some early SDN companies, do you know how that is going?

Donley:  Several MSOs are speaking with their vendors about SDN and NFV, and are experimenting with the technology in their labs.  I will leave it to the MSOs to provide additional details.

What are key SDN and NFV-enabled applications and services that they are experimenting with or deploying, if any?

Donley:  With our members and the vendor community, we’ve been analyzing SDN and NFV use cases at CableLabs over the past year or so.  Some of the promising SDN use cases include dynamic Metro Ethernet and security (firewall, parental controls, carrier-grade NAT, etc.). On the NFV side, we are experimenting with virtual CPE and are starting to explore architectures for virtualizing the cable modem termination system (CMTS) and converged cable access platform (CCAP).

When do you expect the MSOs will actually benefit from SDN and NFV? Is that an optimistic timeframe?

Donley:  Our members will each make their own deployment plans; I can’t comment on exactly when they will see benefit.  That said, we’re working at CableLabs to accelerate the development of SDN and NFV to make sure the technology is ready when it fits into our members’ plans. Personally, I think we’re currently in an "era of ferment," when the technology evolves rapidly, and that it will take at least a few more years for the technology to mature and become widely available in service-provider networks.

Thank you very much for your time, Chris!