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What is SD-WAN and how does it work?
SD-WAN, or Software-Defined Wide Area Network, is an approach to managing and operating wide area networks (WANs) using software-defined networking (SDN) principles. Traditional WANs rely on conventional routing hardware and protocols, but SD-WAN offers a more flexible and cloud-friendly approach, especially useful for businesses that rely heavily on cloud services and SaaS applications.
Here’s a breakdown of SD-WAN and how it works:
Centralized Control: At the heart of SD-WAN is the ability to centralize network control using a software approach. Instead of managing each device and connection individually, network administrators can manage, configure, and optimize the entire WAN through a single dashboard.
Path Selection: SD-WAN can use multiple connections, like MPLS, broadband, LTE, or even satellite links, and then dynamically choose the best path for each application based on policies or real-time network conditions. This ensures optimal performance for critical applications.
Security: SD-WAN solutions often incorporate built-in security features like encryption and firewall, making sure the traffic is secure even over public broadband links. Additionally, the centralized nature of SD-WAN makes it easier to implement and manage security policies across the entire network.
WAN Optimization: SD-WAN solutions can integrate WAN optimization features, such as deduplication, compression, and protocol optimization, to improve application performance across the WAN.
Application-aware routing: SD-WAN can recognize specific applications and then make decisions on how to route that traffic based on predefined policies. For instance, voice traffic might be given priority on a high-quality MPLS link, while bulk data transfers might be routed over a cheaper broadband connection.
Cloud Integration: SD-WAN is designed with cloud-first architectures in mind. It offers a better experience for accessing cloud applications because of its ability to select the most efficient route to the cloud service, avoiding potential traffic bottlenecks.
Simplified Branch Office Networking: Traditional branch office networking requires various devices and complex configurations. With SD-WAN, branch networking can be simplified with a single appliance or even a virtual appliance handling routing, WAN optimization, and security.
Reduced Costs: By using a combination of private MPLS circuits and cheaper broadband internet connections, companies can reduce their reliance on expensive leased lines. This hybrid approach provides both reliability and cost savings.
How it works:
Edge Devices: SD-WAN is implemented using edge devices located at each site. These devices can be physical appliances or virtual ones.
Overlay and Underlay: The SD-WAN creates an overlay network on top of the existing underlay network (which can be any combination of MPLS, broadband, LTE, etc.). The overlay is where the SDN magic happens, with application routing, optimization, and security policies being applied.
Central Controller: SD-WAN systems usually have a central controller that communicates with all edge devices, pushing down policies, and gathering performance data.
Zero-Touch Provisioning: New sites or changes can be added with minimal manual intervention. Once an edge device is installed at a site and connected to the network, it reaches out to the central controller, gets its configuration, and is ready to go.
In summary, SD-WAN is a modern approach to wide-area networking that uses software-defined principles to offer more flexible, cloud-friendly, and cost-effective WAN solutions.