Software-defined networking has in the past year quickly graduated from geek status to mainstream as both established hardware vendors and startup software developers vie to define the future of networking.
SDN is often thought of as the abstraction of the networking control plane, or the system that decides where traffic flows across a network, from the networking data plane, which is the system that actually forwards traffic to its final destination. By moving the control of where the traffic flows to a separate software layer, applications can directly steer traffic across networks and specify the use of certain networking services without regard to specific interfaces used by the underlying hardware.
However, disagreements over how far SDN will go in terms of removing hardware differentiation from consideration forms a chasm between hardware-focused giants and software-focused startups that is only partially being bridged by the adoption of open-source standards.
On one extreme are software developers such as VMware that think all network functionality will eventually be defined in software and run on any hardware from existing networking gear to generic servers.
On the other side are hardware-focused networking vendors such as Cisco, Juniper, Brocade, Hewlett-Packard and Dell, which argue that hardware-specific features define networking performance and quality of service even as some control moves to the software layer.
The potential growth of the market will help gloss over squabbles about SDN. Research firm IDC in December estimated the enterprise and cloud service provider SDN business market could reach $3.7 billion by 2016, up from $360 million in 2013.
An April survey by Swedish research firm Tail-f found that 89 percent of businesses are at least discussing SDN. Companies are looking to the technology for faster deployment of new apps and services, fewer mistakes when deploying those apps and services, faster provisioning of new users or customers, decreased operating expenses, and avoiding vendor lock-in, according to the survey.
Despite their disagreements about SDN, hardware and software vendors both support a number of open-source initiatives that advance it.
Topping the list is OpenFlow, an open-source standard protocol for letting third-party applications determine how network packets move across heterogeneous networks. Networking hardware vendors are increasingly adopting OpenFlow to work side-by-side with their own proprietary protocols to give customers a choice of how they want to control the traffic.
Also receiving much vendor attention is the Linux Foundation's OpenDaylight Project. OpenDaylight, which was unveiled in April, brings together nearly all the major systems, operating systems, and networking hardware and software vendors to develop a common platform for sending APIs to applications that enable those applications to work with multiple SDN protocols including OpenFlow, other standard protocols, and networking vendor-specific interfaces.
SOLUTION PROVIDERS' TAKE
Solution providers for now are betting that the future of networking lies in more software and less hardware.
Dean Cappellazzo, CEO of Bedrock Technology Partners, a San Diego-based solution provider, said he likes where the concept of SDN is going in part because it allows businesses to use their virtualization experts and administrators to help manage networking traffic rather than rely on Cisco Certified Internetworking Experts (CCIEs) or those with similar certifications from other vendors.
"SDN also makes it look like you can put a dumb switch at the edge to prioritize the network traffic instead of going into the switch to do it," Cappellazzo said. "A lot of people buy switches to do that, but then don't use them."
SDN will hurt hardware vendors like Cisco, but it will take time, Cappellazzo said.
"From an enterprise level, Cisco is important for the IT infrastructure," he said. "Customers are not going to pull out Cisco to replace it with SDN. But I do think if customers start migrating to SDN, they'll see it as a more efficient way to manage networks at a lower cost."
Mark Teter, CTO of Advanced Systems Group, a Denver-based solution provider, said it is important to find a way to sort through all the rhetoric about SDN.
"The networking vendors say there's no way software can compete with high-performance ASICs in switches and routers," Teter said. "But that's not what SDN is about. It's about the traffic and intelligence."
BREAKING HARDWARE DEPENDENCIES
VMware in 2012 grabbed the SDN spotlight with its $1.2 billion acquisition of OpenFlow pioneer Nicira, a significant amount for a startup with no revenue-producing customers.
That investment let VMware do with networking what it did with servers: Break the ties between networking functionality and the underlying hardware.
VMware had its own SDN protocol before the Nicira acquisition, and has since united them in its NSX offering. VMware also supports OpenDaylight.
SDN is all about breaking the networking hardware dependency and freeing customers to choose whatever hardware they want for networking based on their applications, said Hatem Naguib, vice president of networking and security at VMware.
"VMware wants to abstract the functionality so that, from a network perspective, all that is needed is an x86 infrastructure," he said. "We say, all you need is IP connectivity. You can choose any vendor you want, and manage everything as a VM."
Stu Bailey, co-founder and CTO of Infoblox, a Santa Clara, Calif.-based developer of software for automating networks, said the best way to understand software-defined networking is to look at what he called "hardware-defined networking."
"An entire industry is organized according to boxes," Bailey said. "Firewalls, load balancers, switches, routers -- under the cover, the hardware looks similar. The difference is in the software. Software-defined networking is really a market correction where the center of value is shifting from hardware to software."
As networking hardware vendors add more SDN capabilities, their perceptions will change positively in the eyes of analysts and customers, Bailey said.
"[All the vendors] have great software," he said. "But can companies like Cisco and Brocade embrace a software-centered business model?"
HARDWARE SUPPLIERS STRATEGIZE
To hear the network hardware vendors talk, embracing an all-software networking business model is necessary and even desirable.
For Cisco, OpenFlow is only one of several facets to the company's SDN strategy, said Omar Sultan, the company's senior manager for data center and cloud marketing.
The company's ONE (Open Network Environment) Foundation includes platform APIs that allow software developers to directly manipulate routers and switches, agents for OpenFlow and onePK, and overlay networks that sit on top of physical infrastructures, Sultan said. onePK is Cisco's software development kit for its ONE platform, and provides developers the same environment Cisco's own engineers use to access networking functions.
For Brocade, which like Cisco bases its SDN strategy on a combination of networking hardware and software-only solutions, there are four layers to SDN technology from the physical and virtual networking devices to the virtualization layer to the application layer to the cloud management layer, said Ken Cheng, the company's vice president of routing, application delivery, and software networking.
"SDN is not one protocol," he said. "It's not one combination of technology. This enables networks to be programmable, to be automatically configurable, and to virtualize networks so they can be configured without the need to configure the physical infrastructure itself."
Brocade supports OpenFlow and is a member of the OpenDaylight Project. The company late last year also acquired Vyatta, giving it a software-based network operating system for SDN.
For Dell with its networking hardware that supports OpenFlow, SDN provides new opportunities as customers shift their focus to end-to-end solutions and away from the individual components, said Art Fewell, technical marketing engineer for Dell's networking business.
"This can lead to a conversation around cost reduction, or around tailored solutions that help drive business needs," Fewell said.
However, Fewell said, OpenFlow is still not a mature networking technology. "So apps being developed today are using some form of proprietary extension. This is something that needs to be done because the standards are not yet fully developed. But even as OpenFlow matures, this will continue. Vendors will always be looking to keep one step ahead of standards for their differentiation."
VMware's Naguib said the only real losers in the move to adopt SDN are those who do not use some type of open-source SDN technology.
"If you believe your solution needs to be proprietary and closed and mapped to one way of doing things, you will be left behind," he said.
PUBLISHED MAY 13, 2013