Guest Blog – Windstream: Differences in the Details, with SD-WAN and SDN

By Yulia Duryea
Director of Product Management, SD-WAN, Windstream
August 10, 2017

Original post:

With IDC now reporting that the software defined WAN (SD-WAN) market is set to hit $8B by 2021, it’s become to networking what the Cloud has become to infrastructure and applications. Most people now understand what SD-WAN means, but it’s still confused with its technology parent, Software Defined Networking (SDN). In this post, our guest blogger, Yulia Duryea with Windstream, explains the difference.


SD” isn’t the only thing SD-WAN and SDN have in common

Beginning with the separation of the Control Plane and the Data Plane, both SD-WAN and SDN share a common heritage. Designed to run on commodity x86 hardware, they can be virtualized, and support the integration of additional Virtual Network Functions (VNFs) like security or WAN acceleration.

[VeloCloud Note: For more on the alphabet soup that is SD-WAN, SDN, NFV, and VNF, check out our recent blog.]

SDN was built to support the modern computing needs found in Local Area Networks (LANs) as well as in Service Provider networks (at Windstream, to deliver wavelength services), creating dynamic, flexible, and scalable connectivity. SDNs are directly programmable, providing an agile centrally managed platform that decouples the Control Plane – decisions about where traffic is routed – from the Data Plane – which determines how traffic is forwarded.

While SDN and SD-WAN share these underlying principles, they are definitely not the same.


Understanding what makes SD-WAN and SDN different

While SDN and SD-WAN are related, they have different applications and usages.

SD-WAN provides software defined application routing to the wide area network (WAN) and connecting an organization’s geographically distributed locations (headquarters, data centers, branch offices, remote and mobile users).

Alternatively, SDN is primarily focused internally, locally within the LAN or within the Service Provider’s core network.

Other essential differences include:

  • SDN is completely programmable by the customer or user, and allows for efficient change and configuration management. While SD-WAN is built on SDN technology, the programming is handled behind the scenes by the SD-WAN vendor, eliminating the complexity for the end user.
  • SDN is focused on the internal network, be it the LAN or the core service provider network. While SD-WAN is focused on enabling connections between networks and users over the WAN.
  • SDN is enabled by NFV, Network Function Virtualization, providing multiple virtualized network functions via software that until now were previously built into proprietary, closed systems. In contrast, SD-WAN provides software defined application routing that can be virtualized and run either virtually or on an SD-WAN appliance.


SD-WAN takes you beyond packets and apps

SD-WAN changes the paradigm from a packet-based network routing system to an application based routing system. With this type of shift, organizations are able to leverage consumer grade broadband while improving quality and performance. Additionally, the cost per megabyte is significantly reduced from what is available with MPLS.

SD-WAN also offers both flexibility and agilitywhile maintaining centralized, pre-defined business policies controlling the routing of applications. The resulting visibility and control allows the identification of applications running across the WAN and setting policies on their prioritization and use.

SD-WAN uses dynamic multi-path optimization (DMPO) to route those apps over the best performing pathways on the WAN. Additionally, SD-WAN lets you use multiple available links in an “active/active” configuration, providing load balancing and failover, with little-to-no perceived interruption. Traffic between sites travels via dynamic, fully-encrypted tunnels and can be segmented, providing for high levels of security.


Not all “SD” technologies are created equal

As I’ve written about before, SD-WAN takes away the complexity for the end user, providing easy to use tools and analytics to support network management.

That simplicity inevitably leads many organizations to attempt a do-it-yourself (DIY) model. Howver, leveraging an experienced service provider can allow the organization to maximize the benefits associated with the technology. This becomes even more important if the SD-WAN solution has to integrate with an existing private or hybrid network.

Knowledgeable providers can help you quickly understand your network and how associated services (voice, video, WiFi, etc.) are configured, and how they collectively may impact your security model.

Now that we’ve removed some of the mystery from what makes SD-WAN and SDN different, you’ll be more prepared than ever to begin moving your organization towards digital transformation fueled by the power of SD-WAN.



About the Author

Yulia Duryea is Director of Product Management at Windstream, where she is the product lead over the Enterprise SD-WAN portfolio. Prior to joining Windstream, Yulia held a variety of product roles at Level 3 Communications, where she managed the product lifecycle of a number of services, including managed security services, managed router, managed UCC, Ethernet and IP-VPN. Yulia holds an MBA from Oregon State University, and a BS from Université Lyon 3, in Lyon, France.

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