Software-Defined Networking: Promises & Challenges

By Jim O'Reilly  |  Posted 2014-11-07 Email Print this article Print
Software-defined networking

Software-defined networking has matured to the point where products, designed from the ground up, are being deployed, but not all vendors are at the same level.

Software-defined networking has matured to the point where products, designed from the ground up, are being deployed. Of course, not all vendors are at the same level, and several startups lead in the vision area, while some of the large vendors play catch-up. However, SDN is still in the early-adopter phase, so the players will evolve and consolidate.

Today, SDN is a best fit for larger IT operations. There's a substantial learning effort in getting started, with the need to understand technical offerings, match them to problems at hand and determine the best fit to IT workloads. This situation is evolving in the direction of ease of use, which opens up the mid-market.

Because there are differences in capabilities between the various offerings, IT has to prioritize objectives before committing to a solution. For instance, if self-service network provisioning is a target, it will dictate different choices than if very high security is the primary aim. This type of analysis provides a scorecard to evaluate the alternatives.

Common objectives that drive SDN include:

  • Agility in creating VPNs, allocating bandwidth and tearing down networks
  • Interfaces that allow users to select from standard networking templates
  • Billing systems interfaces
  • Rapid detection and replacement of failed links
  • Strong firewalling between tenants and the external world
  • Substantial reduction in network personnel hours
  • Auto-scaling with workload and traffic levels.

Building an ROI case for SDN is still an art form. Quantifying intangibles, such as better security or faster response to change requests, is tricky. As a result, there tends to be a focus on tangibles, such as lowered network support costs, reduced acquisition costs and so on. The intangibles are probably much higher value than the tangibles, especially if the whole enterprise becomes more agile as a result.

According to Brad Casemore, director of networking at IDC's Toronto office, SDN is being evaluated and installed by IT operations with sufficient resources to handle a large disruptive task.

"Early adopters like Google and financial services companies such as Goldman-Sachs came up against the limits of traditional networking," he says. "With available resources to do the integration, they've made their infrastructures much more agile." He believes this is going to be a complex vendor environment for the next few years.

Casemore reported that where SDN has been implemented, the savings appear to be around 20 percent in both CAPEX and OPEX, with a notable improvement in agility.

Operational agility is a recurring theme for organizations that are evaluating and deploying SDN products. Joe Skorupa, vice president and distinguished analyst at Gartner, feels strongly that "SDN's value is in software and the flexibility to add it to controllers. This will excite a new level of innovation in networking, with software-only companies adding value."

It's still the early days for SDN, and many organizations are taking a wait-and-see approach. However, SDN does seem likely to eventually live up to its promise of agility and cost savings, while opening up networking.


Jim O’Reilly is a freelance writer, covering the software and hardware industries. He has published more than 300 articles on tech topics.


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