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How CableLabs is Using OpenDaylight

Every week we see new stories about how users are integrating OpenDaylight (ODL) into their networks. This new blog series is a look behind-the-scenes at all the ways service providers and enterprises are using ODL and explores the use cases and implementations that we can all learn from.

First up is a look at CableLabs, a non-profit research and development consortium dedicated to creating innovative ideas that significantly impact the business of its members–comprised of major cable operators worldwide. They are prototyping a number of SDN and NFV use cases to help define interoperable solutions among their members and technology suppliers in order to drive scale, reduce costs, and create competition in the supply chain. We spoke with Chris Donley, Director of Virtualization and Network Evolution at CableLabs and OpenDaylight Advisory Board member.

Please describe at a high-level your general network infrastructure.

Chris Donley: MSOs are looking to offer voice, video, and data services over myriad access technologies including DOCSIS, PON and wireless services. Most of the access infrastructure, particularly for residential services, uses the DOCSIS protocol, and PON services are used primarily for businesses.

Operators are now considering network virtualization in an effort to optimize provisioning services on a common platform that will allow them to rapidly deploy new business and residential services, agnostic to the underlying access network. Also, virtualization promises to improve operational efficiency through the use of self-service portals to monitor Service Level Agreements and rapidly adjust service parameters in response to changing business needs.

What are your biggest networking challenges? What are you doing to overcome them?

Donley: One of the biggest challenges we face is offering services consistently across multiple access networks.  This currently requires multiple provisioning servers, and it is difficult to ensure service consistency across platforms.

To that end, CableLabs’ Open Networking focus team has been exploring the use of SDN in cable networks to reduce our provisioning headaches since mid-2012. We’ve identified the need for a protocol to control the DOCSIS access equipment, particularly the Cable Modem Termination System (CMTS). Through use case analysis, we determined that OpenFlow by itself isn’t sufficient (and isn’t supported in existing CMTSs) and started looking at alternatives. We believe that in the end, operators will use several different protocols within their networks under a unified controller architecture. One protocol used in the cable industry for setting up DOCSIS service flows and applying QoS is Packet Cable Multi Media (PCMM), which is based on COPS, and is widely supported on existing CMTS platforms.

PCMM already has the concept of service flows and we wanted to see if we could augment the existing OpenDaylight flow model such that developers would approach managing flows on a CMTS as if it were another OpenFlow-capable switch. In fact, now cable operators can use PCMM service flows in combination with OpenFlow to dynamically control a cable network and prove out the flexible architecture we’ve been developing within our focus team.

How will SDN and NFV impact your business? What are some of the greatest benefits from your perspective?

Donley: SDN and NFV offers cable operators three primary benefits: faster deployment of new services (in terms of both time to market and quote to cash), more flexibility in how they design their networks, and reduced OpEx, primarily through automation.

While either SDN or NFV each can be implemented independent of one another, we believe that combining these two technologies provides the greatest impact. NFV moves functionality from hardware to software and SDN provides the APIs and control protocols to provide operators the ability to cloud-enable their network functions, taking advantage of cloud scale and velocity.

To this end, CableLabs is collaborating with its members and technology partners on our CableCloud™ initiative, using OpenDaylight, OpenStack, and OPNFV to build prototypes demonstrating virtual CPEs using SDN and NFV. One of our first use cases is to use this platform to rapidly provision Metro Ethernet services from a web portal.

Can you talk about some specific applications of SDN and/or NFV that CableLabs plans to utilize? 

Donley: At CableLabs, our Open Networking focus team works with the cable industry developing SDN and NFV solutions through open source projects. We are developing a plugin for the OpenDaylight network controller that allows application developers to create service flows on a CMTS and cable modem data paths and apply a particular QoS in a similar way to application developers who already use the controller to manage flows on an OpenFlow-enabled switch. Operators now can augment their application with end-to-end flows without needing to know the details of how DOCSIS manages traffic. Cisco and Arris demonstrated our plugin controlling their CMTSs at the SCTE CableTec Expo last fall.

We are also working with our Open Networking focus team to develop a rich set of information models and an architecture for virtualizing the CMTS platform, which is our first step towards a unified provisioning platform for MSO-provided services.

Another project involves developing, prototyping and learning about virtualizing Metro Ethernet services on Open Hardware and embedded Linux platforms, including OpenWRT, Raspberry Pis and Cubietrucks.

Recently, we launched a Virtual Home Network project, designed to provide residential services over a virtualized infrastructure.  As we start our prototyping in the next few weeks, we intend to work with Open Daylight and OPNFV

CableLabs is also engaged with the ETSI NFV Industry Specification Group, where Don Clarke chairs the Network Operators Council (NOC), and we joined Open Platform for NFV (OPNFV), where I serve on the Board of Directors.

We also developed an open source implementation of an IPv6 embedded router that automatically provisions multi-router home networks as our members transition to IPv6.

Why are open source and open standards important to network infrastructure? How much value do you place on the openness of networking solutions at your company?

Donley: The pace of change in the industry is increasing. In order to develop interoperable equipment, it used to be sufficient to discuss the matter in a standards organization until you were able to reach consensus, which may have taken two years or more. Today, that’s too slow.

As the industry moves to software, open source offers a new paradigm that can move much faster.  Now, someone can develop interoperable interfaces in software in a matter of months, and if the interfaces fit other people’s needs, they can be adopted much faster.  In this way, the industry can work together on the 80% of software that delivers 20% of value, and allow vendors to focus more of their developers on their proprietary 20% that delivers most of the value. Artifacts from open source projects can then be brought back into open standards as they become more stable so they can be more readily used by others.

Also, opening up the ecosystem through open source and open standards helps to expand the marketplace (and the development pace) for network application innovations, allowing us to do things that were not possible with closed network stacks.

At CableLabs, open source and open standards are a key aspect of our CableCloud strategy. We’ve been active in organizations such as IETF, ETSI, and MEF for quite some time, and have recently become more active with OpenDaylight and OPNFV.

What is the biggest problem you’ve run into for implementing SDN and/or NFV? How did you solve it?

Donley: The back office (OSS/BSS) is a major consideration and a possible barrier to deploying NFV and SDN. CableLabs is making a significant investment in defining APIs and data models for NFV and SDN-based services, which we believe will help with the OSS/BSS integration.  Short-term, we are starting with virtual CPE solutions, which reduce the integration needs

What are some of the biggest roadblocks to widespread SDN and/or NFV adoption?

Donley: We need a clear migration strategy from today’s network to get us to SDN and NFV.  We also need to maintain the levels of performance and reliability that our customers have come to expect.  Operators want to make sure that the rapid innovation benefits of cloud networking don’t come at the expense of meeting existing Service Level Agreements. I think that the industry is working on these problems, but the solutions will still take some more time to mature.

Why is NFV so important?

Donley: NFV is the first step towards cloud networking.  By moving functions out of the hardware and into user-space software (even if the functions are on the same device), NFV opens the door to innovation and offers the promise of allowing operators to select best-of-breed applications without regards to the underlying software. Also virtualizing network functions decouples feature enhancements from the hardware development cycle, allowing for more rapid development of new services that will delight our subscribers..

What does the industry need to do to speed SDN availability and adoption?

Donley: For service providers, I think there are two key needs. First is a migration path for legacy hardware.  Not all devices support OpenFlow, but we need a common platform to manage them, regardless of which protocol they support.  This is why the OpenDaylight SAL is so important – it allows different southbound plugins for different types of equipment, but can tie them together with common northbound interfaces to allow service creation on whatever devices have been deployed.

The second need is for a richer policy or intent language.  Many existing SDN solutions are focused on data center use cases – how can a web server communicate with a database server?  Service providers are also concerned about what tier of service a customer has selected, or what devices are subject to parental control, for example.

Do you think interoperability is important for SDN to flourish? How do we achieve it?

Donley: Absolutely.  It’s one of the big drivers behind our SDN involvement.  We need a common configuration and management platform for myriad devices, regardless of the vendor or access technology. We can achieve interoperability through well-defined open data models and APIs that provide developers with a stable platform to prototype their ideas. OpenDaylight is a great starting point. We were able to develop the first version of our PCMM plugin in only six weeks.

What is the greatest benefit to having an open source SDN solution in the market? 

Donley: Many hands make light work. Having a common open source SDN solution in the marketplace allows us to focus more on services than on devices. OpenDaylight as a platform allowed us the ability to repurpose a pervasive CMTS protocol and integrate it into a SDN environment alongside other protocols such as OpenFlow and OVSDB. The SAL allows us to SDN-enable existing CMTS platforms while we work with the vendor community to consider support for newer protocols such as NETCONF and RESTCONF in the future.

OpenDaylight as a project allows CableLabs to float ideas as software and bring a slide deck proposal to life quickly. But what I value the most about open source projects like this is that we can collaborate with really smart network and application engineers to shape an SDN concept so operators can deploy and use them.

What do you think are the greatest benefits open source presents to SDN?

Donley: People often say that open source provides “increased quality and reduced cost” making it sound like it is virtually free.  It’s not free, but we can share the cost, and benefit everyone in the end. For instance, 80 percent of the controller code delivers 20 percent of the value. In this environment, it makes sense for the community to jointly develop the common platform so that companies can focus their time on the 20 percent of the network function code that drives 80 percent of the value.

Over the last 10 years cloud innovation took off, based on Agile, DevOps, and Lean Startup methodologies. Open source offers us a way to innovate, prove out concepts, and either fail fast or extend good ideas. The lessons we learned from being part of a community and submitting code to open source projects has helped us galvanize the community around our CableCloud initiative, and directly translates into solutions that our members can apply to their services. These are potentially costly lessons learned at a fraction of the price.


If you’d like to participate in our user series, please contact or give us a shout-out using the #OpenSDN hashtag.

OpenDaylight is building a bridge to SDN for service providers and enterprises. Images of bridges from Environmental Services, Oregon Department of Transportation: Oregon City Bridge (1922), Sellwood Bridge (1925).