Hands up who loves their WAN? I would hazard a guess that there would be very little limb movement at this point!

The Wide Area Network has always been neglected, the unloved one sitting in the corner only getting any attention when it does something wrong. Watching as it’s close relatives, LAN, Firewall and Wi-Fi get all the praise. What people forget is that without the WAN the good stuff quite often just doesn’t happen.

Behind every great transformation is normally a great Wide Area Network. It would be lovely to hear its praise once in a while.

I read a survey recently that said that when asked what CEOs thought of their WAN the most popular response was it’s good enough. This was probably the most damning response possible, even if CEO’s had said it was too costly, or it was too slow, at least there would have been some emotion, some reason to discuss the WAN. So good enough translates as I don’t really care.

But is this about a change?

The marketing would have you believe that SD-WAN is going to transform networking, driving a step change in how we deliver Wide Area Networks by heralding the end for the traditional network provider and retiring some old firm favourites like MPLS.

But is it really this transformational? Or is it more the case that wide area networking has been left alone for 15 years and it is now ripe for a new bit of branding.

Technology moves in cycles and the WAN is no different, back in the 1980’s the first networks were built on packet switching technologies like X.25. Speed 15 years on into the early 1990s and we witnessed the emergence of Frame Relay and

Asynchronous Transfer Mode (ATM) networks, swing a further 15 years forward to the mid 2000s and you saw the introduction of Multiprotocol Label Switching (MPLS). This quickly developed an excellent reputation and became the de-facto standard for secure networking. But, it has been 15 years so it’s probably time for a change.

The History of Networks 1980-2017

So, what is SD-WAN (Software Defined Wide Area Networking)?

Software Defined Networking (SDN) is really about creating agility by controlling the behaviour of physical network components with software. SD-WAN is taking this principle and applying it to Wide Area Networks. In my simple mind I like to think of it as a way, users can maintain the security and reliability of traditional MPLS networks (Underlay) whilst combining the affordability and simplicity of broadband connectivity (Overlay). It’s also about simplifying the edge, a single monoclinous device that can act as switch, router, accelerator or firewall or all of the above. Replacing the need for multiple devices at the edge.

What will be the greatest benefit that SD-WAN will bring to the end customer? 57% said improved network agility and automation.*

The buzz around SD-WAN is everywhere, any Internet search will quickly lead you into the “techsand”* If you listen to the marketing hype then investing in SD-WAN technology today will deliver;

  • Cost savings,
  • Security enhancements,
  • Improvements in network performance & visibility
  • Greater support for real time applications & access to the Cloud
  • Improved network agility & automation

So, let’s look at these claims in a little more detail.

Cost savings

SD-Wan will allow you to balance your connections between the more expensive MPLS connectivity and the more value based broadband services. Consolidating network connections will allow you to “right size” your infrastructure. But in my experience organisations that are using MPLS for reliability and security reasons will continue to use it as part of any SD-WAN solution.

So, a combination of a WAN link (underlay) with a new service (overlay) is unlikely to reduce the network spend. After all the underlay hasn’t changed price. It’s not cheaper because its acting as an underlay as opposed to the primary circuit into a site. In fact, in a recent conversation I had with a leading SD-WAN provider they actually stated that all of their customers now spend more on their WAN since moving to a SD-WAN solution as it drives savings and efficiencies elsewhere in their business.

Security enhancements

For SD-WAN to be successful it needs to be as secure as MPLS. The immediate concerns are focussed around the encryption of the Internet tunnel of the SD-WAN solution. Encryption is sparsely used across MPLS networks as they are inherently secure however people don’t have the same perception of the Internet. The advent of Cloud strategies demand new secure Software Defined Infrastructures. Whatever anyone says to maximise the potential of SD-WAN you will be connecting your edge device to the Internet. This will have to be secured in a more comprehensive way to convince buyers to move away from their traditional trusted networks.

Network performance and visibility

SD-WAN simplifies the management and delivery of corporate networks, increasing reliability by having dual networks and improving application performance, leading to more productive employees and smoother business processes. Silver peak in 2017 stated that “Network organisations can take comfort in knowing that virtually any SD-WAN solution that they implement is likely to make at least a modest improvement in the performance of your network”

Any improvements in network performance are welcome, but I would argue that a well-designed MPLS network with the right management tools will match any SD-WAN advancements. I would also would also worry that the introduction of more noise per frame by the addition of encryption could lead to greater latency and jitter. So, could there be an argument that SD-WAN could introduce network delay.”

SD-WAN adoption will tilt away from an appliance-only model and shift  toward an as-a-service solution.**

Greater Support for real time apps and access to the cloud - SD-WAN allows us to set up rules that monitor the latency of alternate paths connecting a particular site to the cloud, allowing the automatic steering of traffic down the fastest path at any given time. It is argued that publicly accessed cloud computing has rendered traditional WAN architectures suboptimal. Cloud services demand a new generation network like SD-WAN that is more agile and able to support a continually changing set of traffic types and performance requirements.

The counter argument is that MPLS WANs have always supported real-time applications. They also have dedicated pathways to the Cloud across dedicated infrastructure rather than across the Internet. SD-WAN isn’t introducing anything new here. Supporting real-time applications in the overlay is only half the story. If the underlay requires the separation of traffic through the application of different Classes of Services and doesn’t support Quality of Service, you won’t be able to guarantee that you’re able to support real time applications.

Improved network agility and automation

Most companies who are working through a digital strategy are paving a way to automation. Automation is the goal for all new technologies and SD-WAN is no different. The reduction of Wide Area Networking and regional office IT management tasks by using network centralised management and policy-based automation is a fundamental benefit of SD-WAN. SD-WAN makes networks more agile by letting administrators configure them from a central location. The counter argument is that you will still be limited by the physical circuit lead time, especially at the time of the initial installation or when you need to physically upgrade beyond the bearer bandwidth. One of the greatest engineers I have worked with over the years (Ian Hindley) frames it nicely “There is great agility, but it has boundaries”.

What will be the greatest benefit that SD-WAN will bring to the end customer? 17% said improved network performance and visibility.*

In a recent workshop that I run I asked a group of System Integrators, Network Resellers, Communication Service Providers and Wholesale network providers what will the greatest benefit that SD-WAN will bring, their answer was fairly conclusive; 57% said that it was all about creating improved network agility and automation. With cost reduction and increased security not really seen as an initial primary benefit.

This got me thinking, if we take a recent technology development like cloud how do the initial perceived benefits match up to the actual benefits that people are now realising. Interestingly the initial move to Cloud was driven by a perception of cost advantages where the reality it has been about achieving a scalable infrastructure.

I wonder how this will look in the next few years for SD-WAN?

So, If I was going to leave you with some advice it would be this. SD-WAN is an exciting development and will hopefully be a great way to get people talking about their WAN.

The network should be loved and invested in, you need to build the right foundation to allow your business to transform. In many cases SD-WAN will play a part in this foundation but equally it’s not quite time to discard those traditional technologies just yet they will play a fundamental role in the future of next generation networking. If your Network is stopping, you do what you want to do with your business then it’s not right for you. The important thing is that the network should be invisible irrespective of how its built.

Do you want to lay the right foundation to embrace future technological change? Tell us your challenges, so we can find the best solution together. Contact Intercity Technology on 0330 332 7933.

* Source: SD-WAN industry forum 2017
**Source: Forbes - SD-WAN Predictions For 2018

 

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