How are Traditional WANs Different from SD-WANs

Enterprise Security Magazine | Friday, January 14, 2022

Analyzing SD-WAN architecture can be challenging, especially in the expanding market for these services.

FREMONT, CA: SD-WAN solutions and services share the following capabilities: virtualization of the wide-area network connection, centralized policy management, orchestration, and the ability to control traffic dynamically.

Vendors may claim to offer SD-WAN products when they only support a subset of the technology's standard features, a practice known as SD-WAN washing.

Much of an IT professional's grasp of SD-WAN design will come from familiarity with the technology's most frequently used buzzwords. A controller is one such phrase; it refers to a hardware or software client that controls data flow between two places and delivers network and security policies to connected devices. As mentioned previously, another critical SD-WAN term is overlay, which refers to how the SD-WAN architecture sits atop the network. This SD-WAN glossary defines the words used by vendors and service providers to describe SD-WAN.

When considering SD-WAN adoption, enterprises should weigh the benefits of SD-WAN. Once IT teams have verified a sufficient number of benefits, the decision to use the technology becomes evident. For example, suppose an enterprise has accepted the high cost of MPLS to meet mission-critical traffic requirements. In that case, SD-WAN architecture enables the usage of lower-cost links, such as internet circuits.

SD-WAN provides redundancy for WAN connections, automatically switching to a backup path if the primary fails or becomes unavailable. SD-WAN can also optimize application and network performance by balancing several connections.

With the maturation of SD-WAN, many vendors have provided cloud-based SD-WAN alternatives, in which the controller is hosted in the cloud. Extending the controller's reach beyond the data center should offer greater network flexibility and scalability, as well as improved management, and several firms are already doing so.

SD-WAN offers numerous features to help companies manage and maintain their WAN configuration.

SD-WANs provide real-time, automatic, and standardized configuration updates, decreasing the likelihood of human mistake that frequently occurs with traditional WANs' manual programming requirements. Traditional WANs include several characteristics that SD-WANs do not, such as load balancing and disaster recovery. However, adding these capabilities to typical WANs can be time-consuming, complex, and clumsy.

Virtualization's adaptability is critical for addressing corporate expectations. SD-WAN architecture is based on virtualized overlays that simplify the process of redistributing and replicating policies across distributed edge devices. As a company grows, it may leverage existing WAN connections to connect to the SD-WAN device, and IT can administer site policies remotely via the centralized controller.

When comparing SD-WANs to VPNs, significant disparities emerge. For example, while traditional VPNs perform well for enterprises with a single IP backbone, they fail when audio and video are added or when the network becomes congested.

Due to SD-granular WAN's level of support, it is far more advanced in terms of quality of service (QoS) than standard internet VPNs. It's also worth noting that VPNs are not always capable of providing the optimized internet connectivity and improved security that cloud-based applications require.

Perhaps most significantly, SD-WAN automatically detects and visualizes network problems, ensuring a predictable level of performance.