Having designed and implemented many Wide Area Networks throughout my 20 years in the infrastructure delivery industry, I have seen many changes and developments in the types of technologies used.  I still remember installing my first WAN using ISDN2 and Kilo Streams circuits, and for those customers that had a bigger budget, we would use ISDN30 PRI, utilising PPP Multilink to give them 30 x 64Kpbs and the potential of 2Mbps bandwidth.

Now, fast forward 10 years to the around 2005 the focus shifted to MPLS and LES circuit connectivity, the carriers really had their cake and were definitely eating it.  The benefit of being able to use VRFs providing multi-tenancy over the same infrastructure gave huge profit margins and the ability to create their own pricing structure.  The evolution of the MPLS footprint and infrastructure also provided the benefit of full mesh connectivity, bigger bandwidth with higher throughput and data speeds.

So let’s now look at the present day.  The internet is God; connectivity is cheap and available globally.  Companies have been using IPsec VPNs over the Internet to provide their data connectivity requirements for years. However, due to the lack of QoS, the cost of additional hardware, the extra administration and the technical knowledge required to run a pure IPsec WAN solution was the reason this was not embraced, which is why we predominantly see IPsec VPNs as a WAN backup option or small branch connectivity method.

About 18 months ago, service providers such as BT, Verizon and AT&T to name a few, started to realise that SD-WAN was a real threat to their private circuit offering and therefore changed business focus.  SPs knew that the shift to the Internet to provide data connectivity was coming and therefore, they started to plan partnerships with Software-Defined WAN providers. In forming these partnerships, service providers were now able to offer hybrid Software-Defined WAN solutions while continuing to maintain circuit contracts.  The downside to this, is that SP’s will only offer a solution that uses their incumbent partner and not the Software-Defined WAN vendor that provides features and services specific to the customer’s data traffic and application needs.  It is important to mention that not all Software-Defined WAN vendors provide the same functionality.

Before I continue, let me highlight a couple of points, all of which are common knowledge and no secret!

  • Internet circuits are cheap
  • MPLS and private circuits are expensive
  • Bandwidth is bandwidth regardless of the underlying infrastructure
  • By using Software-Defined WAN, QoS is possible over internet circuits and therefore, Voice/Video can be passed over the internet and can still maintain good quality
  • Data passed over the internet can be secure
  • Full mesh connectivity is also possible over the internet
  • Cloud hosted services are becoming more common

So, taking the above into account, why would Software-Defined WAN not be a consideration?

Software-Defined WAN not only creates an overlay network that can be tailored to the customers’ requirements, it also offers optimum path selection, QoS, traffic optimisation, cost-effective, secure connectivity and the ability to bundle together multiple types of connectivity methods and mediums.  Don’t get me wrong; I am not saying that a true Software-Defined WAN solution must be used and MPLS should not be used, but the customer’s connectivity requirements and needs must be considered before making that selection.

So, my question is, why are Systems Integrators and Solution Providers still proposing and selling expensive private circuits to their customers? Surely, it’s the duty of these businesses to offer the best and most cost effective solution to their clients that is future proofed!

Many times over the last 12 – 18 months, WhiteSpider have provided strategic direction to customers, helping them plan for the time that Software-Defined WAN becomes a real contender to provide their connectivity needs.  When deciding the next evolution and development of the WAN connectivity, it’s important to understand the following:-

  • What are the contract end dates of the current private circuits?
  • Replacement WAN costs – expect the year one investment in Software-Defined WAN to be significantly higher than your current year on year WAN costs! Software-Defined WAN is a long-term investment, and if advised correctly savings should be seen from year 2 and beyond.
  • The business strategy, requirements and planning is key to success! Do not just consider the WAN replacement costs and savings.  Consider the option that an Software-Defined WAN solution can remove an existing WAN optimisation solution, and therefore, potentially saving huge costs on hardware maintenance and licensing requirements.
  • Don’t think that Software-Defined WAN can only use DSL, think wider, think about all mediums, including Cellular.
  • Do not just concentrate on a single Software-Defined WAN provider, set out a list of your requirements and perform a technical assessment of what each vendor can provide. Not all Software-Defined WAN vendors will provide what you need! Some do things better than others.
  • Do not think that an Software-Defined WAN solution must be performed by a big service provider, think of the DIY possibility. Once the initial setup has been performed the Orchestration policies are defined, administration and management is massively simplified.
  • Consider any cloud requirements; some Software-Defined WAN solutions can be deployed within the cloud; some can be deployed as virtual or physical appliances.
  • And finally speak to an independent, knowledgeable company that has experience and knowledge in both the Architectural approach and delivery.

Cost Saving Example
During a recent assessment that was performed, WhiteSpider identified the following yearly cost savings that could be made by migrating just Seven of Twenty sites to an SD-WAN solution.

*Costs are realistic.  However, are only provided as an example, specific cost savings can only be provided following a cost analysis exercise.

Final Thoughts
The increasing availability, reliability and low cost of Internet connectivity means that by migrating WAN connectivity to incorporate a mixture of Public and Private connectivity could offer significant CapEx and OpEx cost savings.

By implementing an SD-WAN solution, it is possible to smoothly migrate to a simple, manageable and cost-effective WAN infrastructure over a period of time. Planning the implementation correctly will remove the risk of a big bang approach, and by understanding the costs of current WAN circuits and contracts lengths, a planning phased migration can be performed quickly.

Considerations that should be taken when thinking about your WAN Evolution.