SDN—Not Just Another IT Buzz Word

Software Defined Networking (a.k.a SDN)

Most people know what the terms removable storage, virtualization, mobile, and social media mean. In IT, we refer to these as disruptive technologies, or technologies that, over time, will create new markets and make existing technologies and ways of doing things obsolete. Email and paperless technologies (social media, mobile phones, and virtualization) are all disruptive technologies that have happened in a short period of time and are being used by the general populous. Another technology about to emerge from the pipeline is software defined networking, or SDN in geek speak.

Most technology analysts agree that SDN will become both a disruptive technology and a technology used by the general populous. At a very high level, an SDN is a network that has the ability to dynamically configure itself to optimize a network user’s experience. No, the network engineers of the world haven’t been working on piecing together a sentient being in their spare time, rather they’ve been listening to their users. In order to get a handle on how an SDN works, here are some high-level concepts one must understand in order to grasp the power of a SDN architecture:

1. 1. Data to be sent from one computer to another has information added to it so that it can traverse a network. One piece of data traversing a network can have three different headers added to it; each header contains information relevant to the communicating computers and different devices within a network. These headers are like a fingerprint and will uniquely identify source and destination computers and the application sending the data.

1. 2. Quality of Service (QoS) is a term used in networking to define how an administrator controls what network traffic is prioritized within a network. Currently, QoS runs local to a network device, and is applied to each device by a network engineer. Often times when QoS is applied in a large organization, there are unintended consequences for certain types of traffic. Most network engineers will attest that defining a good QoS strategy for a large network takes time to fine tune and is constantly changing as more types of traffic and devices are coming across a network.

1. 3. Network traffic needs to be handled differently based on the type of traffic it is. For instance, if someone is watching a video across a network, the time parameters for a streaming video are much tighter than they are when a user clicks a button to refresh their email. Even though we are dealing in just milliseconds, how the traffic is handled can greatly impact the user’s experience on a network.

Now, let’s pretend that I’ve just hooked my computer up to a SDN and I try to communicate with another computer; we’ll call them Host X. How is my experience going to be different than the last network that I was on? When my computer starts sending data to Host X, the SDN-capable networking device will read the headers off of my data and send that information to an SDN controller. The controller, acting like the brains of the SDN, is able to determine where my computer is on the network, where Host X is on the network, all the networking devices in between, and the application we’re using. If there is a definition for said application in the controller, the controller can dynamically send out QoS statements to every network device between my computer and Host X. These statements will tell the networking devices how to prioritize the traffic to optimize the network user’s experience.

Often times a network engineer’s ability to please all the people all the time is compromised by lack of time and resources. When faced with the dilemma of making their bosses look good to company executives or having the general network user enjoy their experience, they side with the individual signing their paycheck. Often times, this results in executives disbelieving complaints about network issues and performance. (Why would they? They’re having an optimized network experience.) SDN will allow network engineers to dynamically optimize their network environment so that everyone’s experience is optimized.

While SDN standards, controllers, and hardware are seemingly slow to hit the market, smart decision makers are investing in network hardware companies that are currently selling open standards SDN-capable equipment. This gives them the ability to roll into a software defined network with the purchase of a controller versus having to rip and replace an entire network to implement a disruptive technology they didn’t adopt early on.

About Dan Hutchings
Dan Hutchings is a senior network engineer working in VLCM’s engineering group. In his role, Dan architects solutions for customers, plans and implements network deployments, and works as a consulting engineer.

VLCM, HP, and SDN
HP has been a leader in the SDN space since its inception in 2007. Today, HP is leading the creation of an open SDN ecosystem that is significantly innovative to the world of networking. VLCM partners with HP at the highest level in order to bring such expertise and innovation to its customers. Celebrating 30 years of service in 2013, VLCM is one of the largest technology resellers in Utah. VLCM succeeds because they bring technology into the business planning process and align their customers’ vision with the right technologies and professional on-site service. With a team of more than 25 local engineers, they assess, plan, implement, and service critical business technologies with leading brands such as HP, VMware, and Barracuda.