Software-defined networking (SDN) is quickly moving from the theoretical realm into the real world. Companies like Google have already launched large-scale deployments across multiple data centers, and other organizations are busy testing SDN-managed environments. At an Open Networking Summit (ONS) gathering in April, user groups, manufacturers, and other industry players showcased the progress made so far, and discussed where SDN is headed.
Rick Bauer is technical programs manager at the Open Networking Foundation (ONF), a group based in Menlo Park, California, that's spearheading much of the standards development work on SDN. Bauer attended the recent ONS event, and he reported seeing a range of organizations, from small companies to large Fortune 1000 firms, beginning to roll out SDN through prudent-minded "phased migrations, test labs, and proof-of-concept activities." Presentations by Goldman Sachs and Microsoft were among those showing that SDN deployments are already powering data centers in multiple sectors.
Start small with SDN, advises NEC exec
As other enterprises contemplate moving toward OpenFlow-based environments, "start small" is the mantra of those who have already launched SDN architectures. Selecting a very finite test bed may yield the best long-term results. Don Clark, director of business development at NEC Corporation of America, headquartered in Irving, Texas, said that success with SDN often begins "in the lab environments, in dev test, and by solving very specific problems that organizations are trying to address." From there, enterprises can better understand how further integration into existing environments will play out.
What "start small" means will depend on the company—Clark pointed to one of their customers who deployed SDN and virtualized the entire environment in their backup data center as their pilot program. Many enterprises will opt for something significantly smaller as a launch pad, but even a modest test bed will enable a data center manager to match their company's larger, longer-range plans with the right components. A thoughtful and well-informed move to a more general type of deployment can then follow.
Big Switch exec recommends platforms that will work today and tomorrow
A primary component in any data center future-proofing plan is the acknowledgement that migrations will continue to happen, and that some components of today's technology may remain effective, even after new platforms have been added. SDN is no different. Andrew Harding, senior director of product marketing at Big Switch Networks in Mountain View, California, encouraged enterprises to keep their current needs firmly in mind as they move forward. "Get a platform that can support the data center, that can work with both physical and virtual systems, and can work with systems that are there today—the legacy systems—in addition to the systems that folks will be picking up tomorrow." Selecting a tunnels-only SDN solution, for example, may leave an enterprise with software on the shelf, and by the same token, a switch that doesn't have a plan for scalable OpenFlow support will likely become surplus gear that doesn't work down the road. Any system should be able to coexist with the network architecture that's in place today, to ensure it's also flexible enough to continue supporting the evolution of the enterprise tomorrow.
Open Networking Foundation manager advocates more education
Education is also critical to success with SDN. Folks should understand what it means—and what will change—when the enterprise moves from a hardware-defined, hardware-dominated networking architecture to one that is managed by software. In most cases, moving forward successfully (read: without a bunch of expenditure and system regrets) requires a different way of thinking. "It takes a fair amount of whiteboard time and good resources to help the people in your organization evolve out of the hardware-dominated kinds of biases that naturally have crept it," Bauer explained. How data plane management happens may not be radically altered, but the control plane will be. "You're evolving to a 'Let's look at how we want the management flow of this application or this particular data center to work,'" Bauer said.
A number of manufacturers are active in the SDN market, some with existing products that have been retooled to fit software-driven fabrics, and others that have introduced components designed expressly for SDN environments. Bauer said several manufacturers "have been in our labs early and often, and they have worked to produce product solutions that were conformant from the very get-go." For data centers interested in additional insight as they review potential solutions, Bauer said that more information on ONF's conformance test program will be released later this year.
SDN products to watch
NEC Corporation is one manufacturer that has released a number of products that target SDN. The company's ProgrammableFlow line includes the PF6800 OpenFlow-based SDN controller, which Clark said is a scalable appliance designed for high availability. There are also several switches in the same product family. The PF5200 series of hybrid switches run traditional Layer 2/Layer 3 protocols and OpenFlow on the same switch, making them ideal for environments mixing SDN and legacy architectures. These hybrid versions also boast very large capacities, supporting up to 160,000 flow table entries. NEC's PF5820 is a high-density, low-latency, dedicated OpenFlow switch. Data centers running Windows Hyper-V environments can opt for the PF1000. "That gives Windows customers the ability to administrate both physical and virtual networks from a single pane of glass," Clark said.
Big Switch also has a suite of products for the SDN sector. Their Big Network Controller is joined by the Big Virtual Switch, a network virtualization application focused primarily on OpenStack environments, but which offers physical and virtual network virtualization through support of both tunnels and OpenFlow ports. The company's unified network monitoring application, Big Tap, enables significant flexibility and visibility into data center networks. "In contrast to traditional port mirroring or tapping solutions, Big Tap can put a layer in front of tap aggregation or other tools that enables users to get a high level of flexibility," Harding said. Going into beta in June is Switch Light, firmware for switching that works in concert with Big Switch's controllers and enables a multipath fabric. Versions of Switch Light will be available for both Broadcom and Linux.
Even as SDN infiltrates the enterprise, Bauer is quick to say that it isn't a magic potion for fixing every networking problem. Transitioning to SDN by investing in a swath of components and implementing a data center-wide forklift upgrade may be a good way to find some of your new equipment gathering dust down the road. Bauer said he believes that maintaining a focus on a vendor-agnostic approach is key, and he encouraged data center managers to ask potential vendors some hard questions about the openness of their solutions. "If I was purchasing hardware equipment, I would want to make sure I wasn't going down a very expensive cul-de-sac and finding that my switch infrastructure is not going to evolve in ways that SDN architecture and OpenFlow are already evolving," he said.
Julie Knudson is a freelance writer whose articles have appeared in technology magazines including BizTech, Processor, and For the Record. She has covered technology issues for publications in other industries, from foodservice to insurance, and she also writes a recurring column in Integrated Systems Contractor magazine. Follow her on Twitter: @julieknudson.