"SDN is ready to go," says Kaoru Yano, chairman of the Japanese tech giant NEC to his audience at the Open Networking Summit in Silicon Valley this week. At a conference last fall on software-defined networking (SDN), many presenters spoke of the promise of SDN to bring the same type of virtualization to the network that has made server and storage IT resources more efficient. This time, presenters such as Yano described actual implementation of SDN in production data centers. Although SDN has a long way to go before it’s anything approaching mainstream technology--and many cautions about it remain--it is making demonstrable progress.
Yano explains that the push for SDN is being driven by the explosive growth of network traffic from video, machine-to-machine communication and smart devices. "The SDN industry grows explosively, [and it is] time for network users to be prepared for building the instant network to take advantage of SDN."
SDN is being developed to eliminate the bottleneck that occurs when increasing amounts of data in virtualized servers and storage hits the legacy network. Although there is some automation technology already available, such as virtual LANs, SDN decouples the control plane from the data plane. Network intelligence is centralized, and the physical network infrastructure is abstracted from the applications. That means that software in the controller plane augments the intelligence in the physical network to make it more efficient.
The Open Networking Summit is hosted by the Open Networking Foundation, which is promoting the OpenFlow protocol that enables SDN. At this second ONS in just six months, speakers such as Yano detailed case studies of how OpenFlow-enabled SDN is working in production. Yano explained how two NEC customers benefited from SDN implementations.
The first was Genesis Hosting Solutions, a virtual infrastructure company based in Chicago that found its network structure incredibly complex and difficult to scale. The company was also running out of IP addresses. Genesis deployed a number of NEC ProgrammableFlow Controllers, a switch and a management console. The result was that it reduced network administration by 100 hours a week with improved automation, reduced IP consumption by up to 60% and was able to reach its goal of five-nines network availability.
In another example, NEC brought SDN to Nippon Express, a global logistics company based in Japan. Nippon found it had limited flexibility for modifying networks in virtual environments and sought to create a private cloud by 2014. With SDN, the company reduced the amount of switch rack space it needed by 70%, reduced power consumption by 80%, reduced failure recovery time by 98% and reduced network outsourcing costs by 100%.
"In the traditional tiered hierarchical model of network deployments, we have equipment tiered to provide the kind of resiliency that the data center would expect," says Donald Clark, director of corporate business development for NEC. "With the software-defined model, the resiliency is logically assigned in software and then deployed throughout the switches. So we don’t need the same level of physical redundancy in order to get the level of resiliency required for services."
NEC also realized the benefits of SDN for itself in converting some of its own data centers, Yano said, adding that immediately after the earthquake and tsunami that devastated Japan in March 2011, the company had to scramble to transfer workloads from a data center near the epicenter of the quake to one on the western side of the island, a task that would have been easier if SDN had been enabled.
Representatives of Google also presented case studies on SDN projects at some of its data centers, and other presenters shared their success stories.
Yet in spite of those successes, there is still reason to think through an SDN project. "SDN is perhaps a decade-long journey," said Geng Lin, CTO of networking business at Dell.
While citing some low-hanging-fruit for SDN, Lin said SDN needs to be evaluated as part of an "ecosystem" and a "business value chain" of related technology that has to be considered, from the hardware and the merchant silicon within it to the programming language that would be used to provide intelligence to control the routers and switches.
"Each player in the value chain has a role to play in order to achieve the full benefits of SDN. Everyone needs to evolve and needs to evolve collaborate," he said.
SDN is certainly maturing, notes Eric Hanselman, research director for networks at The 451 Group. "People are actually starting to apply software-defined networking broadly, and OpenFlow [specifically], to solve some real-world problems," he says. "There are real applications where SDN provides some specific benefit.”
To Lin’s point about looking at SDN in the context of the broader ecosystem, Hanselman says there has to be some integration with management,the orchestration system and other elements. But a company the size of Google can make SDN work because it "has legions of of development staff to make that happen." At the same time, he acknowledges, for many other organizations an SDN project has to be managed carefully.
