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Advancing the Enterprise with SD-WAN: The Basics

Advancing the Enterprise with SD-WAN: The Basics

Software-defined WAN, or SD-WAN, is a dynamic approach to bridging hybrid WAN deployments – a combination of private and public VPNs. While the choice of MPLS networks and Internet-based (IPsec) VPNs has existed in the market for decades now, an SD-WAN solution makes it possible to leverage both public and private circuits simultaneously in a highly agile and intelligent manner.

SD-WAN capability is enabled over a physical or virtual appliance at the customer premises, which is remotely programmed, managed, and customized based on highly specific, pre-defined business policies. The SD-WAN solution uses a network overlay mechanism to abstract the underlying network infrastructure to utilize multiple transport networks (MPLS, Internet, Ethernet, LTE wireless) in an active/active configuration, and dynamically choose the most appropriate link based on application priority and current performance conditions. For example: A major coffee chain with highly distributed locations can define business policies for both POS and Guest WiFi services to get high priority to promote their customer loyalty program. Meaning the controller ensures high QoS on network paths for both of these applications, as opposed to routing guest WiFi traffic on low quality Internet links.

With SD-WAN, the determination of application path across the networks is dynamic in nature as the controller tracks and analyzes the application traffic in real-time so it can route it (and re-route if required) to achieve optimal performance and an improved user/customer experience. The SD-WAN functionality can be compared in a very simple way to the popular GPS application – WAZE – that routes drivers around vehicle traffic congestion in real-time. This approach is highly efficient compared to traditional hybrid WAN deployments, in which application paths are static in nature and do not take into account changes to application flow and performance.

Key features making SD-WAN attractive to enterprises

  • Network Visibility and Analytics – In SD-WAN, the central controller has knowledge of all the customer prem devices and the traffic paths among them. The controller constantly monitors the network paths and its performance characteristics, which are available to network administrators via a graphical user interface approach. In short, SD-WAN management platforms offer the same visibility and analytics into network performance characteristics offered by MPLS VPN solutions.
  • Simplified Network Management – SD-WAN reduces the need for proprietary hardware, allowing your network team to remotely program and quickly and easily manage the system via a centralized software controller. This eliminates the need for network personnel’s physical presence to provision and program CPE at every branch site.
  • Increased operational efficiency – SD-WAN creates an active/active connection, which allows enterprises to efficiently utilize bandwidth across network assets – public, private and wireless networks. Meaning, you can reduce your company’s reliance on expensive private networks, and instead add inexpensive Internet links to run less mission-critical applications. Network administrators can define policies to choose the best performing path for mission critical applications requiring high levels of performance; for example, real-time applications such as voice and video service, while low priority applications run over slower links.
  • Increased deployment speeds – The plug-and-play nature and zero touch provisioning of SD-WAN means you can be up and running in a matter of minutes vs. days, weeks or months (MPLS installs can take 60-90 days). The SD-WAN equipment can be installed by a non-technical person, and a site configured using LTE to start with, if broadband is not immediately available. This is a huge improvement compared to the long provision cycles of MPLS VPNs.

SD-WAN and Cloud Connectivity

As cloud becomes an increasingly integral part of enterprise deployments, the hairpinning model of routing branch sites’ traffic via MPLS hub locations is inefficient and adds to the delay. SD-WAN enables enterprises to keep critical applications on MPLS, and directly connect users to cloud-based applications over cost-effective Internet-based links.  The flexibility to choose different access options is particularly helpful for connecting remote employees and branch sites to cloud-based applications as it improves per site economics.

Moving to an SD-WAN solution can enable organizations to augment MPLS with Internet, and extend its useful life while meeting business demands. Enterprises also get access to newfound power to define performance policies to control, inspect and choose the right path for their applications. For most enterprises, this is far more sensible, easier and less traumatic than the rip and replace alternative.

DIY or work with a Network Service Provider?

As your organization considers embracing SD-WAN, an important question that might come up is whether you should do it all alone (working directly with a hardware/software provider) or work with a network service provider, instead.

There are several benefits to the latter option; one being tapping into the managed services expertise of an experienced NSP as you transition your traditional WAN to SD-WAN. We will discuss the role of Network Service Providers in SD-WAN in part two of this post.

Image Credit: channelbiz.es


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Guest blog post by Roopa Honnachari from Frost & Sullivan, a global consulting firm and a strategic partner to EarthLink. They work with clients to leverage visionary innovation that addresses the global challenges and related growth opportunities that will make or break today’s market participants. This is the first in two-part series on SD-WAN. 


About Roopa Honnachari

Roopa Honnachari
Our guest blogger is Roopa Honnachari of Frost & Sullivan. Roopa leads the Business Communication Services practice at Frost & Sullivan. She is an authority in the wholesale and business network services space, with 14 years of experience spanning market research, growth consulting, and technical marketing in the communication services industry. She monitors market developments in the wholesale and retail network services (MPLS VPN, Ethernet, Waves, etc.), managed network services and cloud networking.