As early as 2011, analyst firms such as IDC were documenting the challenges with Wide Area Network (WAN) environments. In its top 10 predictions for 2011, IDC mentioned the WAN was reaching a breaking point due to the pressures of cloud and security requirements. More recently, Gartner said that “by 2021, more than 65% of WAN edge infrastructure refresh initiatives will be based on SD-WAN versus traditional routers, up from less than 30% as of 2Q18”.

Between one prediction and the other, something we’re all familiar with has happened: the number of users, things, connections and clouds has grown at exponential rates. All the while, the WAN architecture remained pretty much unchanged. This is the WAN that was designed to connect a fixed location to a data center, which no longer is the requirement. The requirement is to connect multiple locations and mobile users to multiple clouds – something a traditional WAN can’t ensure without raising bandwidth, user experience, management and security challenges. 

Houston, we have a problem – Start with Hybrid WAN

The first response to the pressures of cloud applications and bandwidth was hybrid WAN. Hybrid WAN augmented an existing WAN link, with an additional (often lower quality, but higher bandwidth) connection. This link was usually encrypted as it was often an internet link.

The remote site was configured to prefer different links for different applications, thereby load balancing across them on a per-application basis. For example, cloud applications could use the encrypted internet link back to the corporate data center, while corporate applications would continue to use the MPLS link.

This simple approach definitely provided more bandwidth and helped with addressing some of the cloud application challenges, but there were still a number of limitations. For example, hybrid WAN did not take into account the dynamic response times of WAN links and the number of links were limited (usually to two). Also, it didn’t offer centralized management nor a distributed security model to avoid backhauling all traffic to a corporate data center to go out to the internet.

Re-imagining WAN Architecture: SD-WAN is born

To address the limitations of hybrid WAN a different approach was required. And the answer was   Software defined WAN, or SD-WAN.  There are three critical aspects that define SD-WAN and positively changed user experience, performance and security.

The first aspect is the control plane. Essentially, a central brain that looks at the WAN as a whole and makes dynamic decisions about which applications should use which links based on the performance of those links. The second one is the ability to offer an overlay, or a way of abstracting physical WAN connections, allowing multiple WAN connections (e.g. internet, cellular and MPLS) to be treated as an aggregated connection, increasing WAN bandwidth and performance. Lastly, SD-WAN architecture offers in-built security that is policy-driven, hence easier to apply and manage.

All of this can be defined, provisioned and monitored through a single pane of glass.

So many SD-WAN options, what sets them apart?

As SD-WAN has matured, the noise and confusion in the market have too with the emergence of so many players. Not just that, some concerns have grown in terms of managing user expectations around cloud applications, increasing WAN performance requirements and coping with an increasingly decentralized security model.

Cisco SD-WAN helps companies address all these challenges in a very unique way, by integrating all the security capabilities, such as segmentation, NG-FW/IDS, URL filtering, DNS protection into the hardware (which by the way you don’t have to replace) to provide companies with an unprecedented level of security. All you need is our single pane of glass to deploy, configure and monitor security in real-time. Cisco is also the only one to provide real-time visibility and 40% better performance of O365, one of the most widely used SaaS application globally.

Cisco was just named a leader in the 2018 Gartner Magic Quadrant for the WAN Edge Infrastructure – possibly the best testament to our market leadership.

So many SD-WAN solutions, what will you choose?

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