How virtual, hybrid and SD-WANs compare and contrast

Different WAN technologies

Software-defined networking (SDN) has played a major role in reshaping wide-area networks (WANs). So much so that other WAN technologies, such virtual WAN and hybrid WAN, are often mistakenly conflated with SD-WAN. While virtual and hybrid WAN technologies share similar goals with SD-WAN, there are important differences to bear in mind when choosing a solution.

SD-WAN

SD-WAN is based upon the principles of SDN, which is a kind of architecture that allows network behavior to be centrally controlled using application program interfaces (APIs). Applying the principles of SDN to WAN technology can help connect enterprise networks by determining the optimal way to route traffic to and from data centers and branch offices. It also provides an affordable alternative to expensive routing hardware.

vWAN

vWAN is a branch of SD-WAN. The technology is geared toward businesses that want to substitute their private WAN with broadband connectivity. vWANs serve as on-premises products, consisting of a mix of physical and virtual appliances launched at the WAN nodes.

In addition to providing broadband connectivity, vWAN traffic is secured using encryption, which involves converting text into code to thwart unauthorized access. Moreover, the technology aggregates WAN links, including broadband, allowing multiple public network links to work as one big link. vWAN can also load balance over multiple communication channels, depending on the status of the links that make up the big link.

Hybrid WAN

Hybrid WAN, on the other hand, is used to connect two distant WANs to a single branch office leveraging various connections to route the traffic. The technology uses a combination of multi-protocol label switching (MPLS), carrier Ethernet and T3 links. Routing traffic with multiple links can provide network engineers with sufficient bandwidth as needed and help ensure application performance.

Hybrid WAN differs from SD-WAN in that it routes traffic with various connections based on policies and available bandwidth. In theory, hybrid WAN is a stepping stone toward SD-WAN, where path selection and configuration are controlled by policies. Although several hybrid WANs include a SDN component, it is not essential to the technology.