SD-WAN (software-defined WAN)

This definition is part of our Essential Guide: New WAN tools, techniques and methods you need to know
Contributor(s): Alissa Irei

Software-defined WAN (SD-WAN) is an approach to designing and deploying an enterprise wide area network (WAN) that uses software-defined networking (SDN) to determine the most effective way to route traffic to remote locations.

SD-WAN shifts traffic monitoring and management from physical devices to the application itself, capitalizing on SDN's flexibility and agility. Intelligence is abstracted into a virtual overlay -- enabling a secured pooling of both private and public connections and permitting automation, centralized network control, and agile, real-time traffic management over multiple links. This model enables a network administrator to remotely program edge appliances via a central controller, reducing provisioning times and minimizing or eliminating the need to manually configure traditional routers in branch locations.

SD-WAN products and services vary by vendor, but many enable hybrid WAN -- dynamically routing traffic over both private and public links, such as leased MPLS links and broadband, Long Term Evolution (LTE) and/or wireless. An SD-WAN architecture allows administrators to reduce or eliminate reliance on expensive leased MPLS circuits by sending lower priority, less-sensitive data over cheaper public Internet connections, reserving private links for mission-critical or latency-sensitive traffic like VoIP. The flexible nature of SD-WAN also reduces the need for over-provisioning, reducing overall WAN expenses.

SD-WAN is a compelling early SDN use case, as it has the potential to offer clear cost savings while improving overall connectivity between branch locations, the central office and the cloud. The overlay technology is also relatively easy to implement in pilot testing, making it attractive to decision-makers who might shy away from a rip-and-replace approach.

What is SD-WAN
This was last updated in August 2015

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Good morning to everyone. Please I want to know the difference between the 'characteristics of SD-WAN' and the 'purposes of SD-WAN'. Thanks.


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