09 July 2020

How to make the most of SD-WAN.
BY Brian McElligott

The growth of cloud and online services has made companies increasingly dependent on the quality and capacity of their connectivity, which is why next-generation network technology sparks so much interest. Right now there is lot of talk about SD-WAN, but mixed messages about what it can and can’t do for a business.

Ideal for multi-site enterprises, where different locations have different network requirements, SD-WAN works best as an overlay on existing MPLS infrastructure, as a complementary technology that will make branch locations more agile and efficient.

Understanding the real benefits.

Be wary of hype about swapping out MPLS for SD-WAN to make huge savings, or ‘plug-and-play’ capabilities that supposedly make quick work of connecting remote sites to the internet.  Neither stand up to much scrutiny for a network technology that has to be deployed carefully and strategically, ideally with a Total Communications Service Provider who is willing to take time to understand your business and the role that SD-WAN can play in optimising operational effectiveness.

Claims that SD-WAN can deliver savings of up to 30 percent are predicated on the high cost of MPLS in the US where many of the solutions were developed. In Europe, networking price structures are much more competitive. There are real cost benefits from the technology, but they come from network management efficiencies achieved over time rather than in upfront savings at the point of purchase. 

Using SD-WAN as a straight replacement for robust MPLS networks is not recommended. If you require predictable latency, guaranteed levels of service and reliability, MPLS technology is still the best  way to go. Similarly, implementing  SD-WAN as a quick fix for an internet connection to branch sites needs to be carefully planned. There is a lot of effort required if you are trying to connect multiple sites, which may involve opening up your network to different providers, then managing those relationships and various SLAs.

The upfront design requirements for SD-WAN should be carefully thought through, because you are setting up rules centrally that will be pushed out to different locations.  

Introducing application awareness.

The big benefits of SD-WAN are around application awareness, a hot topic for enterprises that run increasingly bandwidth hungry services across multiple networks. While MPLS provides insights into network traffic, it isn’t great for analysing causes of congestion. SD-WAN provides granular detail of what’s happening and the behaviour of specific applications – invaluable information for ensuring there’s always adequate bandwidth for business critical functions.

So if you are a retailer and credit card transactions are the lifeblood of your branch network, SD-WAN is good fit.  It will let you prioritise traffic, the EPOS connection over a public WiFi service, for example, because it will be better to keep a direct  revenue channel open rather than a ‘nice-to-have’ customer service offering.

SD-WAN makes management of WAN connectivity simpler and strategic and will strike a chord with a range of sectors, from  retail and food production to service industries like construction and waste management, where distributed offices are run from a central hub. Similarly, multinational industries involved in pharma, tech or healthcare will have different sites with distinct connectivity requirements.

Cloud-based SD-WAN solutions also mean less downtime. Last mile connectivity with MPLS is active-passive which means a service like VoIP could suffer downtime while failover occurs. When SD-WAN has two nodes actively running the same kind of service simultaneously, it brings active-active redundancy to the WAN. Failover is seamless and downtime avoided.

Hybrid networks for hybrid services.

Most businesses now take a hybrid combination of IT services – from public and private clouds as well as their own data centres – typically run from virtualised servers. A useful way to understand SD-WAN is to think about it doing something similar for networks.

Because it decouples the network control layer from the hardware, SD-WAN platforms can host a range of virtualised network functions and facilitate hybrid connectivity. It provides an overlay across existing MPLS infrastructure, delivering a combination of devices and connectivity which can all be managed through a ‘single pane of glass’. 

By keeping underlay and overlay networks separate, SD-WAN can be used to significantly enhance existing MPLS networks. Better reporting and visibility help network and operations teams optimise infrastructure. If something or someone hogs more bandwidth than they should, it will come to their attention and they can do something about it.  It’s also a win for the business, because they prioritise critical applications on a site-by-site basis.

Basically, SD-WAN enables organisations to get much smarter about bandwidth and moves network management up the value chain. The sooner your business familiarises itself with the technology, the better the chance of maximising the opportunity it presents.

Find out about Three’s newly launched SD-WAN offering here.