SD-WAN: What it is and what it isn’t

SD WAN is fast becoming ubiquitous and, at some level, integrated into everything we do.

In its purest sense, Software Defined Wide Area Networks is exactly that, a software defined series of rules that span a diverse series of WANs. Rules that dictate network path selection on a per application basis.

Or put even simpler; your rules, someone else’s network(s)

So, with that incredibly loose definition, we can start to say what does (and doesn’t) fall within this set:

• A hub and spoke network driven by IP SEC tunnels – not SD WAN in the truest sense, but software defined
• An MPLS? Well, no, not a software defined network
• Multiple internet providers with a software overlay defining path selection, failover and application prioritisation? Sounds like SD WAN!
• An Azure based multi-site network? Well.. Yep, it’s SD WAN!

If seemingly anything can fall under the monitor of SD WAN, how then does an astute buyer begin to differentiate between the various options that exist within the marketplace?

Each SD WAN provider will perform one or all of these tasks to varying degrees:

• Centralised visibility of network traffic
• Dynamic network path selection
• Multi-link aggregation and failover control
• Layer 7 application routing and prioritisation
• Performance and network optimisation
• Centralised device management
• SASE integration
• Cloud Onramp
• Flexible commercial models (from PAYG to outright ownership)

To quote “oils ain’t oils” and so it is with SD WAN. To select the one that works best for you, it pays to consider:

• Where you’re headed?
  •  Is Cloud in your future?
  • Are you committed to delivering services on-premises for the foreseeable future?
• How do employees or customers access your IT services?
• Are you moving towards a zero trust model?
• How much equipment do you want at the edge?
• Do you have an existing stack you’re looking to build out or integrate with?
• Is Cloud performance a factor?
• Do you have the internal capability to manage your network?

One thing is for certain however, more and more providers are integrating some form of SD WAN capability into their edge devices and you can only expect to hear more from this space.

So the next time someone hits you up regarding SD WAN, my advice? – 

Get a clear view of where you’re headed in the next 3 years and realise that SD WAN will likely form part of your future in some way.