Blog post

I hate my WAN…SD-WAN to the rescue

By Andrew Lerner | July 07, 2015 | 1 Comment

WANSD-WANNetworkingJust Published

I’ve yet to run across a Gartner client that loves their WAN. It’s crazy if you think about it:

  • The time to get additional WAN bandwidth is typically measured in weeks/ months.
  • WAN costs are measured in hundreds of (US) dollars p/month p/mbps (for MPLS).

Further, as apps move to the public Internet with increasing frequency, there’s an increasing desire to sprinkle Internet access into the traditional WAN to optimize performance and price. Sounds great, but it can be pretty hard to do with traditional router-based WANs. Ultimately, application performance suffers. This has been the norm in the WAN for years, and most clients have come to expect this.  The general mainstream sentiment is along the lines of “other than cost and performance, my WAN is fine”.  Reminds me of the old line:  other than that, how was the play, Mrs. Lincoln….


However, there is a new technology to the rescue called SD-WAN. SD-WAN dramatically improves the cost and complexity associated with traditional WANs. The key components of an SD-WAN solution include:

  1. A lightweight replacement for traditional WAN routers that are agnostic to WAN transport (i.e., support MPLS, Internet, LTE, etc.) and can physically terminate carrier circuits.
  2. Support for load sharing of traffic across multiple WAN connections in an efficient and dynamic fashion that can be based on business and/or application policies.
  3. SD-WAN solutions dramatically simplify the complexity associated with management, configuration and orchestration of WANs. The level of expertise required to configure the branch is akin to what is required to setup a basic home wireless network with consumer-grade equipment.
  4. SD-WAN solutions must provide secure VPN and have the ability to integrate additional network services (i.e., firewall, Wan Optimization, SWG etc.).

There are further details in the full published research note, but this is the main gist. Right now, it is very early days for SDWAN, and there are several vendors that offer products including both established and newer/smaller players. While it’s early days, we anticipate rapid uptick in adoption (way faster than data Center SDN), so we just published an SD-WAN Tech Overview, in which we define SDWAN and identify key considerations when considering deployment:

Technology Overview for SD-WAN

Summary: SD-WAN is an emerging technology that offers several benefits compared with traditional, router-based WANs. Network decision makers can achieve cost savings, increased agility and simplification with an SD-WAN. This research defines SD-WAN and highlights its benefits, risks and alternatives.

Happy reading


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Leave a Comment

1 Comment

  • Hi Andrew, WAN seems to be the bane of network managers’ lives. I think investment can be easily justified because the productivity of everyone using the network is impacted by the network’s performance. What is more, network functionality as a service reduces the cash outlay. Let’s get on with it.