What Is SD-WAN?

SD-WAN (software-defined wide area network) is a type of networking technology that uses software-defined networking (SDN) principles to manage and optimize the performance of wide area networks (WANs). It enables organizations to securely connect users, applications and data across multiple locations while providing improved performance, reliability and scalability. SD-WAN also simplifies the management of WANs by providing centralized control and visibility over the entire network.

How Does SD-WAN Work?

SD-WAN is a virtualized service that connects and extends enterprise networks over large geographical distances. WANs use links such as multiprotocol label switching (MPLS), wireless, broadband, virtual private networks (VPNs) and the internet to give users in branch and remote offices access to corporate applications, services and resources, allowing them to work regardless of location. SD-WAN also monitors the performance of WAN connections and manages traffic in an effort to maintain high speeds and optimize connectivity.

Traditional WANs use legacy routers to connect remote users to applications hosted in data centers. A router is mostly command line interface (CLI) driven. To define where and how the data egresses a branch network utilizing traditional WAN, network engineers and administrators must manually write rules and policies. Such procedures are frequently time-consuming and error-prone.

SD-WAN is designed to solve the multiple challenges associated with traditional WAN, allowing networking professionals a simpler way to optimize and secure WAN connectivity. SD-WAN is based on software rather than hardware and is configured to handle different kinds of traffic and conditions in real-time. It can adapt quickly to changing situations and offer better security and reliability than traditional WANs.

SD-WAN uses a centralized control plane to route traffic, allowing administrators to write rules and policies and deploy them across an entire network at once.

Control is detached from the hardware to simplify network management and enhance service delivery. SD-WAN appliances obey operational regulations passed down from the central SD-WAN controller. This significantly reduces or eliminates the need to manage gateways and routers individually.

SD-WAN gateways support hybrid WAN, which means that each branch appliance can support multiple connections via various means of transport, such as MPLS, broadband internet, LTE and so on. For security reasons, a virtual private network (VPN) is typically installed across each WAN connection.

By allowing the WAN to use a variety of different connection types (including LTE, MPLS, and broadband internet) interchangeably, network bandwidth is increased, as is performance and redundancy, allowing for centralized management and administration. Individual gateway and router management is greatly reduced or eliminated when operational policies and rules are passed down across an entire network at the same time.

What Are the Main Components of SD-WAN?

Flexible WAN Connectivity

Flexible WAN connectivity allows for the efficient use of bandwidth between sites and the data center by reducing latency, increasing throughput and improving reliability, using multiple routes—all of which help reduce costs. This allows companies to access their network from anywhere using any device or operating system with an internet connection. If you're away from your office or on the road and need access to your company's servers or databases, SD-WAN will help you do so securely.

Secure Connectivity

Secure connectivity ensures that traffic is encrypted between sites so no one can eavesdrop on it. This is important because all data transmitted over the internet—even if it's just in an email—is vulnerable to being intercepted and read by someone else, who could use that information against you or your company.

Secure connectivity means that the data you send through your SD-WAN is encrypted in such a way that only you can access it—even if someone were able to intercept it while it travels across the internet. This is particularly important when sending sensitive information like credit card numbers or personal health records over public networks like Wi-Fi hotspots at hotels or cafes where anyone could be listening in on your conversation.

Discover how SD-WAN’s efficient and secure network infrastructure can handle the increasing volume of data generated by IoT devices: How SD-WAN Helps Today’s IoT.

Application Optimization

Application optimization is a key component of SD-WAN. This feature enables you to optimize applications that have been identified as being sensitive to latency and packet loss. For example, if you’re running a VoIP call over the internet, application optimization can help ensure that your calls are always connected and clear.

Application optimization ensures that applications can run smoothly even when they need more bandwidth than normal. That way, users won't experience any issues while they're working remotely from home or while traveling abroad on business trips because their connection isn't reliable enough to handle their needs without slowing down or dropping out altogether.

With application optimization, you can choose whether to optimize all applications or just those that have been identified as sensitive to latency and packet loss. If you choose the latter option, then only those applications will be optimized.

What Are the Benefits of SD-WAN?

Businesses that prioritize the cloud can employ an SD-WAN to give users a better application quality of experience (QoEx). While making sure that apps get the QoS and security policies they require, an SD-WAN gives WAN connections insight. With the greatest levels of cloud performance, secure access to cloud resources is made possible by a working local internet breakout of IaaS and SaaS application traffic from the branch office. While doing so, enterprise networks are kept safe.

SD-WAN technology is ideal for small and mid-size businesses with limited budgets, allowing for access to all of the benefits of a large enterprise network without having to pay top dollar. SD-WAN also offers a number of benefits to large distributed organizations with branch offices located all over the world.

Operational Simplicity

Because each device is centrally managed, with routing based on application policies, network administrators can create and update security rules in real time as network requirements change. By combining SD-WAN with zero-touch provisioning — which helps automate deployment and configuration processes — organizations can further reduce the complexity, resources and opex required to stand up new sites.

Find out how SD-WAN Automation simplifies network operations.

Carrier-Independent WAN connectivity

SD-WAN allows for use of multiple internet service providers (ISPs) depending on where you are located or the best price available at the time. You can also choose which ISP you want to use in each location, so if one goes down or has problems connecting, your network won't be affected.

Improved Performance

SD-WAN allows automatic provisioning of application policies that align to business intent. Intelligently steering traffic based on service level agreements (SLAs), SD-WAN ensures application performance is maintained, while continuously measuring WAN performance. Such a proactive approach enables SD-WAN to remediate performance degradation by failing over to better-performing WAN links.

Cost Savings

Network administrators can scale up or down their WAN connections based on actual demand. Network administrators can supplement or substitute expensive MPLS with broadband connectivity options. This also reduces the amount of capital expenditure required by eliminating unused capacity at any given time. Because it's easier to manage than traditional networks (since it requires less configuration), there are fewer ongoing costs associated with maintenance and support.

Improved Connectivity

By allowing efficient access to cloud-based resources without the need to backhaul traffic to centralized locations, organizations can provide a better user experience. Static routes are replaced with dynamic ones that adapt to changing network conditions in real time, which means there's no lag between the source and destination when sending files or video streams over long distances.

Increased Security

With software-defined networking, you can protect your network from external threats like DDoS attacks and malware. You can also prevent internal threats like hacking or data theft by only allowing authorized devices onto your network. This means that if someone tries to get into your system from an unapproved location, they'll just be blocked out automatically.

Improved Reliability

With SD-WAN, you can ensure that all of your data stays connected regardless of internet connectivity or physical location. Your employees will always have access to their data no matter what happens with their internet connection or cellular service — and they'll never have to worry about missing important emails or calls because they forgot their phone at home!

SD-WAN vs. MPLS

SD-WAN makes it easier to manage and direct traffic across a network. With traditional networking approaches like MPLS, traffic created in the branch is returned, or “backhauled,” to a centralized internet security point in a headquarters data center. Backhauling traffic can lower application performance, which hinders productivity and the user experience.

Learn more about how SD-WAN differs from traditional MPLS.

Because MPLS networks are private networks built for one given organization, they are considered reliable and secure, but they are expensive. Moreover, MPLS is not designed to handle the high volumes of WAN traffic that result from software-as-a-service (SaaS) applications and cloud adoption.

Compared to traditional WANs, SD-WANs can manage multiple types of connections, including MPLS, broadband, LTE and others, as well as support applications hosted in data centers, public and private clouds, and SaaS services. SD-WAN can route application traffic over the best path in real-time. In the case of cloud, SD-WAN can forward internet- and cloud-bound traffic directly out to the branch without backhauling.

Compare SD-WAN vs MPLS vs Internet: What’s the Difference? Which is Right for Your Organization?

SD-WAN vs. VPN

VPNs are a great cost-effective solution for organizations that support remote working (i.e., work from home). VPNs secure remote workforces by providing a secure connection to the organization’s network. However, VPNs can’t match up to SD-WAN in cost, performance or reliability. When scaling a large remote workforce, the complexity and latency of a VPN outweigh the cost benefits. SD-WAN offers optimized performance features like the quality of service (QoS) and application routing, embracing the cloud in a way that’s impossible with VPN. Whereas VPNs rely on the public internet for speed and bandwidth, SD-WANs offer enterprises the comfort of service-level agreements (SLAs) for performance.

Find out how SD-WAN and SASE Relate.

The Future of Digital Transformation

As IT teams continue to struggle with rapid digital adoption and exponentially more data, SD-WAN solutions with integrated artificial intelligence for IT operations (AIOps) have emerged as the key to automating manual tasks. AIOps can help IT teams with anomaly detection, event correlation and root cause analysis, allowing administrators to easily pinpoint issues and speed up response times for problem remediation. SD-WAN solutions with integrated AIOps capabilities will help organizations continuously scale and simplify operations.

Learn why Machine Learning (ML) and Artificial Intelligence (AI) are key technologies for SD-WAN.

Next-Generation SD-WAN

Legacy SD-WAN solutions struggle with the shift to cloud adoption and high-performance bandwidth. There is a growing need for a next-generation SD-WAN solution that delivers essential branch services — such as networking, security and more — from the cloud.

A next-gen SD-WAN solution should deliver:
- Exceptional user experience
- Simplified operations
- Improved security outcomes

Find out if you need Next-Generation SD-WAN.

SD-WAN and Branch

A next-generation SD-WAN solution enables all branch services, including networking, security and voice services, to be delivered from the cloud. A secure SD-WAN connection gives organizations peace of mind that branch locations are protected from threats, provides optimal performance for end users and can deliver an ROI of up to 243%.

Learn more about securing branch networks with SD-WAN and how Prisma SD-WAN can help your branch networks.

SD-WAN FAQs

Q: Why is SD-WAN needed?

A: As more and more businesses become reliant on internet connectivity for business-critical and cloud applications, SD-WAN is becoming a necessity. SD-WAN is designed to improve uptime and business agility while reducing operational costs and complexity . In addition, SD-WAN brings management simplicity with a centralized console that allows businesses to control and scale branch networks. It provides the flexibility to connect any carrier independent WAN to increase bandwidth availability and reliable connectivity in a cost-effective way.

Q: Will SD-WAN replace MPLS?

A: Yes, SD-WAN can replace MPLS to provide direct connectivity to the cloud and internet. At the same time, SD-WAN allows businesses to augment MPLS with broadband connections for better WAN availability. SD-WAN relies on relatively low-cost network connections (e.g., broadband internet) for most traffic, saving more expensive and higher-performance connections (such as MPLS circuits) for application traffic. Rather than wasting MPLS bandwidth on low-priority applications, this allows organizations to optimize their networking investments.

Q: Is SD-WAN secure?

A: SD-WAN provides enterprise-level encryption for every link in the WAN. SD-WAN defaults to leveraging the highest encryption and authentication to construct overlay tunnels to datacenters, cloud or other branches. Additionally, it ensures periodic and frequent refresh of the encryption keys that protects these encrypted WAN tunnels more effectively in comparison to VPN tunnels. This ensures that the attackers are unable to intercept, modify, or forge messages that are sent between the sites.

Q: Is SD-WAN better than VPN?

A: Yes, SD-WAN provides a more seamless user experience for businesses that need a secure network connection. With SD-WAN, you can extend WAN to different datacenters, branches, and public clouds automatically, thereby minimizing manual operations. In addition, SD-WAN improves performance and streamlines operations for businesses using cloud-based and SaaS applications by enabling direct connectivity to these apps. SD-WAN also supports remote workers who work from home, public places or anywhere else. It allows traffic to be restricted based on user profiles and also offers more flexibility with respect to network connectivity when compared with VPN (broadband internet, LTE, 4G, or MPLS as WAN connections).