Software-defined networking: 'Virtualization's last mile'

Now that server, storage, application, and data virtualization is underway at many organizations, networks are poised as the next great frontier of abstraction. Enter software-defined networking (SDN), which will bring more benefits to organizations than simply more efficient networks.

"The datacenter's resources may be dynamic, but the communications between them are still static and brittle."

That's the word from a recent report (PDF) out of Accenture, which observes that SDN takes two forms — network virtualization and network programmability.

Network virtualization, Accenture explains, "creates a network in the software realm, all the way down to virtual switches and routers. This frees applications from the need to understand the internal intricacies of the physical network". Network programmability, on the other hand, involves "centralizing control of the routers and switches in order to reconfigure them as infrastructure changes".

The market is fragmented, and no single vendor dominates emerging SDN space. The Accenture report cites high-profile examples of SDN at work. Google, for one, has adopted the OpenFlow protocol "to boost utilization on its internal network". Google anticipates that soon it "will approach 100 percent utilization of the company network" with the programmability of SDN — compared to the industry-wide average of 30 percent to 40 percent utilization of networks.

In another instance, Verizon "anticipates using SDN to relieve loads on individual datacenters to redirect traffic to other, less-utilized datacenters in different time zones". Another high-profile operation, eBay, employs SDN "to be innovative faster", the report noted. "Not only can eBay's developers create and test new network-based products and services faster, but eBay can deploy those services faster."

SDN has promise, but Accenture also has some words of caution: "SDN is complex because of all that it touches. It requires tools and frameworks that are still developing. The interim alternative of doing it yourself is time consuming and expensive. There's a difference between virtualizing your datacenter and virtualizing your entire network. But on the former scale, the benefits are too tangible to ignore."