Skip to main content

SD-WAN White paper

Everything you (always) wanted to know about SD-WAN

A technological breakthrough on the same scale as MPLS in the early 2000s, SD-WAN is at the heart of infrastructure transformation. Read on to find out all about this solution of the future, as well as our own experience with some large deployments and an exclusive CASINO Group testimonial.


I – A reminder of the technology
II – What is the purpose of SD-WAN ?
III – An overview of the market players
IV – How to choose your SD-WAN
V – Client case study : CASINO Group
VI – How to deploy SD-WAN


Le SD-WAN is located at the convergence of three worlds:

  • the world of routing
  • the world of security
  • and the world of application QoS (Quality of Service)

The world of intelligent routage : unlike OSPF, RIP and all the other regular protocols, SD-WAN’s intelligent routing is based on performance. This means that decisions are made made based on the quality of the underlying links : if the link, or the main path, is that of the Internet, it will switch to MPLS if the Internet connection fails. This sets it apart from traditional network.

Another thing to remember, is that it is possible to combine overlay and underlay ; overlay allows to tunnel and therefore completely move away from the notion of underlying physical networks. But tunnelling can be resource-intensive, at the expense of a native many-to-any over MPLS. You can therefore choose, particularly on the MPLS component, to favour underlay, i.e., to switch directly to MPLS without tunnels.

Another interesting aspect about SD-WAN is aggregation. Up until now, an MPLS link, for example, could not be aggregated with an Internet link. This is now possible with SD-WAN; links can be aggregated and identified by SD-WAN as one component. Sessions can be set up allowing to go far beyond the size of physical links, something not possible in a traditional network.
This is known as bonding or tunnel bonding.

A additional very interesting and new aspect – that was not possible until now, in a purely MPLS network, for example -, is the local breakout, i.e., the possibility of going straight to the Internet and accessing Office 365 or Salesforce. This is a highly anticipated SD-WAN feature, made possible by a component included in SD-WAN – security.


Public Cloud, migration, technical capabilities, TOM, 6R, Retain, Retire, Rehosting, Replateforming, Repurchase, Refactoring