SD-WAN is an enterprise technology that simplifies branch office connectivity, optimizes application performance, and improves security. To do this, it automates traffic steering based on preconfigured application policies and real-time network conditions.
It also enables enterprises to utilize diverse network circuits like MPLS, broadband Internet, and cellular options for network connectivity. It provides transport independence, allowing IT teams to prioritize and route applications based on business needs.
Network Topology
A network topology defines the way data transmission flows among the devices that form the network. You can create the logical topology that best suits your needs using a network diagram. For example, a ring topology works well for networks that use redundancy so that a single point of failure does not disrupt the entire system. A tree topology is more efficient for network traffic traveling up and down multiple levels.
SD-WAN enables enterprises to optimize applications for performance and user experience. It converges networking and security services into a software-delivered service model that reduces deployment costs, speeds up time to value, and improves IT operations.
The centralized control function of an SD-WAN prioritizes and steers traffic securely across the Internet or a private wide area network connection. By ensuring consistent application performance and resiliency, enabling secure connections to cloud vendors, and automating traffic steering in an application-driven manner based on business intent, an SD-WAN provides a high-quality user experience and increases productivity.
In contrast to traditional networking approaches, in which backhaul traffic is created at branch offices to a centralized IT network in the headquarters, SD-WAN allows branch office users to exit directly to the public Internet. By doing so, an organization avoids expensive MPLS circuits while retaining advanced security for branch office users. The cost savings come from eliminating the need for a costly MPLS circuit and reducing ongoing operating costs from offloading access to the public Internet.
Network Routing
The basics of SD-WAN route application traffic directly from the WAN Edge to the Internet as an alternative to backhauling all traffic from branch offices to a central security point in the data center. It lowers network latency and enhances the functionality of applications. Additionally, SD-WAN can significantly reduce networking costs because Internet connectivity is less expensive than MPLS circuits.
An SD-WAN’s centralized controller uses policy to determine how each site’s connections are routed using the overlay and underlay networks. The edge routers send connection requests to the controller to check policy, then make connections locally. SD-WAN software running on CPE (customer premises equipment) also analyzes the characteristics of each public or private data service, like MPLS, broadband Internet, 4G LTE wireless, and more, to decide which one will provide optimal performance for each application.
Unlike traditional WANs, an SD-WAN provides complete visibility into network usage. IT professionals can see how applications perform between sites, the cloud, and data centers. Vendor-specific flow fields exported by SD-WANs like Silver Peak, Cisco, and VMware — along with Kentik’s real-time telemetry — give NetOps a holistic picture of the entire network. Using this information, they can change the SD-WAN fabric to improve application performance and increase bandwidth utilization. For example, suppose the MPLS link to a particular site becomes congested. In that case, the SD-WAN will redirect that traffic to an alternate path, such as a private data service or an affordable broadband Internet connection.
Network Security
The business demands of today and tomorrow make the ability to connect users to cloud applications critical securely. Yet, traditional WAN technology is built for linking physical locations, creating expensive global connectivity and costly topologies to maintain. It’s also an easy target for attackers who leverage misconfigurations, software vulnerabilities, and other attack surfaces.
With an SD-WAN, you can centrally configure security policies that apply to all devices simultaneously. These policies can be changed quickly based on the needs of the business. As a result, you can avoid the expense of deploying and maintaining point products across the network and ensure consistency and accuracy of security settings across the LAN-WAN-data center and LAN-Internet connections.
In addition, an SD-WAN can help ensure secure connectivity. Data is encrypted as it travels over the WAN, protecting against unauthorized access. It is significant for sites that use Wi-Fi hotspots to connect to the Internet or work remotely.
An SD-WAN can also provide more flexible WAN connectivity, providing greater bandwidth between sites and the data center while decreasing costs. It is possible because SD-WAN uses multiple routes to minimize latency, reduce packet loss, and improve reliability. Lastly, an SD-WAN can optimize the performance of specific applications more sensitive to latency and congestion. For example, videoconferencing, VoIP, and other high-performance applications can benefit from low latency and a consistent, stable connection.
Network Management
The management side of SD-WAN connects with the network to manage connections and traffic. This connectivity is managed by an edge appliance that sends connection requests to a central controller, or hub, over a secure and private connection to check the policy before making the connection decision for an end-user. The controller also collects telemetry from the edge appliances and uses this data to improve network performance.
Unlike traditional routers that use a command line interface (CLI) to configure routing protocols, an SD-WAN solution enables networking professionals to create a network policy via a GUI. This approach reduces manual configuration efforts, network complexity, and vulnerability to human error.
An SD-WAN centrally controls overlay and underlay transport services to ensure consistent application performance and resiliency. It also automates traffic steering in an application-driven way based on business intent, which increases user productivity and business agility.
Another benefit is cost savings, as the ability to prioritize cloud access over less expensive public internet links reduces reliance on expensive leased lines for underlay transport. For example, enterprises can use low-cost broadband and wireless (4G/5G) WAN links for backhauling from branch offices to headquarters versus the traditional MPLS option. It simplifies the WAN and improves bandwidth efficiency. Finally, an SD-WAN can ingest the flow and telemetry from various vendors to provide network observability and a single interface for management and reporting.