What Software-Defined Networking Means for the Enterprise Cloud

Written by Zeeshan Naseh

A big reason why companies are using virtualization is to make more efficient use of hardware such as servers. So-called “virtual machines” – meaning software programs that emulate how given pieces of hardware work – essentially allow one set of hardware to do several jobs at once on many different machines.  

Now, a relatively new approach promises to bring this same basic idea to networks that carry phone calls, data and video. It is being billed as the largest disruption to the way computer networks are designed and operated since the introduction of TCP/IP paradigm more than two decades ago.

Software-defined networking, or SDN for short, allows a central software program (rather than hardware) control networks that move the data, video and phone calls from one place to another. A somewhat more technical definition is that SDN separates what’s known as the “data plane” – the part of the network that moves data packets – from the “control plane,” which handles jobs like routing traffic and configuring and operating the network.

This is vital for cloud computing because the emerging field of SDN may make it less expensive – and faster – to build networks that carry large amounts of traffic. 

SDN Puts Scalability at Your Fingertips

Perhaps more importantly, SDN should allow these networks to be changed around quickly, easily and inexpensively, along with making them faster and more efficient, according to technology author Brian Proffitt.

That’s because a central software program, in theory, can “see” how the whole of the network, rather than just pieces of it, are functioning at a given time. If one server is overloaded, the controlling software can parcel out its work to nearby devices. And if a given section of the network has more traffic than it can handle, the management software can make adjustments on the fly to ensure data gets to its destination in the fastest and most efficient manner possible.

The result could be wholesale improvements to technology networks. For instance, previous techniques for setting up and managing networks made it tough to use them for research, because of the need to buy and deploy pricey hardware.

Much Still to be Resolved in the SDN World

We’re using a lot of “shoulds” and “mays” and other conditional language because SDN is new. Like any new technology system or approach, there are bugs to be worked out and problems to be resolved. The main issue is a lack of standard “rules of the road” for determining which voice/video/data traffic gets to go where, and how priority is established for traffic within networks.

To paraphrase Proffitt, there at least two efforts underway to establish the SDN equivalent of traffic rules so that software applications and data won’t be left crashing into each other at virtual intersections.

One is the OpenFlow protocol from the Open Networking Foundation (ONF), which describes itself on its web site as a user-driven organization seeking widespread adoption of SDN through open standards development. Initially designed by researchers at Stanford, Berkeley, and MIT in March 2008, members initially included companies (such as Verizon, Google and Microsoft) that were large cloud service providers and looking to reduce costs by building commodity hardware and deploying open-source software.

The second effort is under way at the Linux Foundation through its OpenDaylight Project (ODP) initiative, started on April 2013. This forum is dominated by incumbent vendors such as Cisco, IBM and HP, and there were concerns that the group could be used to stifle innovation and benefit the status quo.  The first code from the OpenDaylight Project (named Hydrogen), however, supported OpenFlow and was released in December 2013.

A third separate effort, called OpenCompute Project (OCP), was initiated by Facebook in July 2011. It sought to build one of the most efficient computing infrastructures (server and storage) at the lowest possible cost. In September 2013, Networking was added to the OCP charter to “forego traditional closed and proprietary network switches in favor of a fully open network technology stack.”

Many Acronyms, One Simple Concept: SDN

The buyer world is divided into two camps: Enterprises and Service Providers. Not surprisingly, they have formed their own consortiums. Financial Services firms led the charge for the Enterprise sector and formed the Open Networking User Group (ONUG), where end users exchanged ideas and benefitted from early innovators’ experiences with SDN. Bank of America, Fidelity Investments and Citigroup, among the pioneers of ONUG in February 2013, agreed on the importance of open networking and the impact on DevOps.

On the Service Provider side, on October 2012 many of the world’s largest carriers banded together with unprecedented collaboration to drive the Network Functions Virtualisation (NFV) initiative. Their main concern was implementing network functions in software that can run on a range of industry standard server hardware, and that can be moved to, or instantiated in, various locations in the network as required, without the need to install new equipment.

In summary, some acronyms to remember: ONF, ODP, OCP, ONUG and NFV. All are used to explain one simple concept – SDN. Clearly, in such a high-stakes game, no one is willing to yield an inch and be judged by Wall Street for their OpEx/CapEx margins falling short relative to their peers. As the Vice President of Business Development, one of the best parts of my job is educating the end customer and persuading them to think differently about their data center, Cloud and IT networking strategy.

Just how all these different initiatives mesh remains to be seen. Assuming they’re successful, they should, according to Proffitt, allow application developers and others to use their tools to quickly and efficiently get data through software defined networks, rather than having to learn the rules of the road themselves.

SDN Ushers in a New Era for Cloud

While all that is being worked out, industry analysts are getting excited about the prospects for SDN to help deliver the self-service private and hybrid cloud options that the marketplace wants and needs.

In one recent publication, Forrester analysts called emerging software-defined approaches to cloud computing “genuinely new and different” and said they will allow enterprises to focus on what’s important: the customer.

“Software-defined infrastructure amplifies consolidation and developer access,” the analysts wrote, adding that SDN “pools compute, storage, and network resources together and makes them accessible through application programming interfaces (APIs) or service catalogs.

Indeed, SDN is a key characteristic of new Cloud Management Platforms that have gained momentum in recent months by virtue of their ability to reduce time to market (months to minutes) and cost while delivering improved performance and security.

Both Forrester and Gartner have noted that the market is poised to embrace this emerging class, which offers enterprises the ability to scale cloud capacity up or down via an intuitive, self-service web interface. (In the next blog, we’ll explore some explicit do’s and don’ts for enterprise cloud computing from Forrester.)

As the promise becomes reality, we can all offer a tip o’ the cap to SDN, which makes it all possible.