For detailed SD-WAN Vendor and Open Source comparisons, checkout the Virtual Edge Expanding: The 2016 SD-WAN and vCPE Report also available as PDF Download
What’s the Difference Between Hybrid WAN vs SD-WAN?
Hybrid WAN is used to connect two geographically separate WANs to a branch office using two different types of connections to carry the traffic. Software-defined wide area networking (SD-WAN) refers to network operators leveraging software-defined networking (SDN) to deliver services across MPLS, LTE, or broadband.
The two technologies share similarities in that they are both used to make the existing WAN more agile and flexible and to solve problems that exist with outdated WAN technologies.
In fact some, like InfoVista, consider hybrid WAN to be a step toward SD-WAN. For example, a large enterprise uses MPLS from a service provider for its sites, but it often deploys an additional network to off-load some applications to its private data centers and streamline its traffic.
Many believe the reason large enterprises rely on MPLS is because it comes with a service agreement that provides additional services like central billing, help desk services, and more. But hybrid WAN offers analytics, service provisioning, and other services that are worth considering.
SD-WAN involves separating the control plane from the data plan and integrating the WAN and branch networks into a single end-to-end framework that uses policies to manage traffic. It also uses generic data plane devices in the branch.
What makes it appealing to enterprises is that it offers open hardware platforms and standardized network links that can reduce prices for WAN. It also offers hardware that can be managed via the cloud by a service provider, which reduces the need for the customer to manage it. It offers the conveniences like self-service portals and self provisioning. And it also offers cloud services such as WAN optimization and application & policy control for more efficient bandwidth usage.
Virtual WAN and SD-WAN
One area less commonly talked about is the virtual WAN (vWAN), which is considered a part of SD-WAN. vWANs are used by companies to replace their private WAN services with regular broadband connectivity. vWANs are used to secure the connection and encrypt the traffic across public networks providing an additional layer of security through secure socket layer offload.
vWAN also aggregates WAN links like broadband, making multiple dedicated or public network links function as a single large link. This helps with applications. They also are used for load balancing across various communications channels because they can selectively route flows and packets based upon link performance.