What Are The Requirements For SD-LAN?

Last time, we opined that SD-LAN would need to focus on much more than throughput and related performance metrics alone in order to make a meaningful contribution to the WLAN space. We also offered that WLAN system architecture – again, most often discussed in terms of throughput alone – is the single most important element in establishing the effectiveness of any given SD-LAN implementation.

But, since our industry has primarily defined itself via advances in performance, let’s start there in examining the requirements for successful SD-LAN implementations.

Performance, of course, has become a catchall term, typically, and it’s been primarily applied to the throughput of a given solution.

This definition is also very narrow, so around here we always expand any discussion of performance to include *capacity, support for the time-bounded traffic critical to voice and video, and, yes, security as well –which must be comprehensive, efficient, and easy to use. After all, no other dimension of performance is important if security is in any way compromised. (*the ability of a given solution to meets the needs of a potentially large, concurrent base of users with often widely-differing traffic requirements, but always desirous of and benefiting from latency as minimal as possible.)

One of the key performance challenges we face today is the wide variety of traffic demands seen in essentially every organization – networks are called upon to support a wide range of traffic types, all applications, and geographically- (and temporally-) varying (but always-growing) user demand.

The key, then, is in minimizing any latency users might experience. Also key is delivering the information, without delay, when and where it’s needed. Networks exist, after all, to enhance the productivitySD-LAN should be able to help here by dynamically adjusting internal network settings to meet traffic policies and instantaneous demand – think magic hand on the flow knob. of workers. SD-LAN should be able to help here by dynamically adjusting internal network settings to meet traffic policies and instantaneous demand – think magic hand on the flow knob.

With respect to security, SD-LAN must be able to leverage local authentication mechanisms, which include identity management, and ultimately determine such essentials as authorization (permissions) and (often) encryption keys.

Granularity down to the level of individual users and devices is essential here, along with location, time of day, user role, and other capabilities as may be deemed important in local operational policies, such as BYOD, guest access, and support for IoT (which is going to be very important as Wi-Fi becomes the preferred vehicle here).

SD-LAN also makes it easier to respond to security threats as they materialize, and simplified onboarding is another possible feature as well. Perhaps most important to security, though, is single-point-of-control system-wide uniformity.

Flexibility and dynamic adaptability are often cited as key benefits of and justifications for SDN, and the same is true for SD-LAN. By basing core implementations as well as policies in software, network shops can realize enhanced configurability, scalability, continuity, and the simplified handling of a wide range of error conditions and the rare but still-challenging outright failure.

Reconfigurations to enhance overall performance (say, for end-of-month processing, or switching a radio in an AP from 2.4 to 5 GHz) are similarly policy-driven and transparent. And, finally, we believe that having an API will be an essential feature of any SD-LAN implementation to provide a common, open mechanism for extensibility, customization, and future-proofing. Examples here include APIs for presence, location, configuration, monitoring, identity, and more.

Finally, with respect to cost-effectiveness, SD-LAN must demonstrate that implementations can (really, will) have a positive impact on costs, particularly with respect to labor-intensive OpEx (operating expense) rapidly outpacing CapEx (capital expense.) We don’t, by the way, expect any bumps in cost here due to SD-LAN as the major component in total cost of ownership (TCO).

Let’s face it – operations staffs still require all the productivity they can muster; budgets and staffing levels aren’t going back to the pre-recession days, so this is where SD-LAN could conceivably really close the deal.

Given that SD-LAN implementations must be self-optimizing, self-organizing, self-configuring, and self-reorganizing and reconfiguring in response to changing conditions across the board, operations-staff productivity should be enhanced with day-to-day work largely limited to policy management and occasional troubleshooting and end-user assistance.

Over time, the number of conditions requiring the attention of management staff should decline, as automation capabilities learn the ropes. And, of course, the advent of SD-LAN presents a great opportunity to move to Cloud-based management, which offers lower costs (including Cloud-based licensing models) and maximum visibility with anytime/anywhere convenience.

So there, in a nutshell, are the overarching features of SD-LAN – performance, flexibility, adaptability, and cost-effectiveness. Next time, we’ll look at how these features translate into quantifiable benefits for network managers and end-users alike, and close with why WLAN system architecture is key to SD-LAN success.

All posts in this series

  1. Introducing the Software-Defined LAN: SDN at the Edge, and More (1 of 3 in a series by Craig Mathias)
  2. What Are The Requirements For SD-LAN? (2 of 3 in a series by Craig Mathias)
  3. What Are The Benefits of SD-LAN? (3 of 3 in a series by Craig Mathias)

For More Info on SDN, Read This Series of Articles By Marko Tisler

  1. Software Defined
  2. The Many Colours of SDN
  3. The Coming Age of SDN

For More Info on SDN, Read This Series of Articles By Craig Mathais


Craig J. Mathias is a Principal with Farpoint Group, an advisory firm specializing in wireless networking and mobile IT. Founded in 1991, Farpoint Group works with technology developers, manufacturers, carriers and operators, enterprises, and the financial community. Craig is an internationally-recognized industry and technology analyst, consultant, conference and event speaker, and author. He currently writes columns for Boundless, Connected Futures, CIO.com, and various sites at TechTarget. Craig holds an Sc.B. degree in Computer Science from Brown University, and is a member of the Society of Sigma Xi and the IEEE.

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