The Point of Software Defined Networking

Carole Warner Reece

I’ve been thinking about many of the topics that were discussed in the recent Software Defined Data Center (SDDC) Symposium and Networking Field Day (NFD6) meetings I attended last month.

What really stands out for me is that the use case for Software Defined Networking (SDN) is extremely compelling – simplistically stated, SDN is the ability to simplify network operation through automation. But that is not the complete story — SDN provides an opportunity to make the network more transparent, applications more visible, and business requirements more integrated.

Nuage Networks talked about SDN and the importance of abstractions. For example, the abstraction of a network service such as a firewall would be the templates that set policy and resources for the firewall. The network administrator would design and configure the service template, and the users would just permitted or denied access to resources based on the firwall policies.

However, in the near term SDN abstraction of services and network automation simply will not be available pervasively across an organization. So a good question is where can SDN be effectively applied now, is it data centers or the enterprise or with service providers or someplace else?

Many of my customers are enterprise based. They are looking to reduce operational risk (of moves and changes) while supporting business agility. For the enterprise user, I see a couple of questions:

  • What is the timeframe for SDN for the enterprise when they already have an installed base of network gear?
  • Can they connect new SDN technology to existing legacy systems and achieve business benefits?
  • Will the technology threaten people’s jobs? (If so, it will be very hard to bring it into enterprise.)

One underlying IT issue is that compute / storage / network connectivity / network services are often very separate groups in an organization. A specific technology such as SDN is not going to resolve organizational processes or operational issues between separate groups.

Several aspects of cloud based computing have made the SDDC the best fit for the initial focus of SDN:

  • Cloud based computing is an environment where multiple organizations are using shared resources. (They are using the cloud to reduce operational costs/risks and to provide business agility.)
  • The cloud service provider is a new organization. Their business processes have not been entrenched for years.
  • Cloud computing can include compute, storage, and network services. The details of cloud computing are hidden from the end user. The end user just needs to attach to it, and they do not have to completely change their existing business processes to use them.
  • Policy management can centralized to a cloud. For the emerging SDN tools, centralized control is quite helpful. Templates can be centrally developed for the cloud environment, and then applied to diverse user groups.

One speaker from Plexxi said that SDDC can provide a system level perspective of the network based on business requirements.

Will SDN investments meet ROI requirements? Maybe not initially, but eventually SDN will help us model applications across entire system. It will make networks more agile and responsive to business requirements. SDN will make the business perform better when the network is better supporting the applications. I’m looking forward to deploying it.

— cwr

Twitter: @cwreece



This is my first article reviewing the technologies and discussions from NFD6. The Networking Tech Field Day events are organized by Gestalt IT who also select the delegates. Gestalt IT covered most of my travel expenses. (Thanks again Stephen, Tom, and Claire for both putting together the event and inviting me to participate!)

These events are sponsored by networking vendors who therefore indirectly cover the NFD delegate’s travel expenses. In addition to a presentation, vendors may give the delegates shirts, pens, or other promotional items. The vendors sponsoring Tech Field Day events do not ask for, nor are they promised any kind of consideration in articles or blogs by delegates. The time spent in presentations and discussion does get me and the other delegate looking at and thinking about the various vendors’ products, marketing spin, and their points of view. I intend to remain as objective as possible, and all opinions expressed here are my own and not those of sponsoring vendors or my employer.

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