SD-WAN: Your Roadmap to SASE

In Article 1: Simple Introduction to SASE, we gave a brief explanation about SASE solution starting with: History and what drive its rise, Definition details, Components and Why it's considered the future. please feel free to visit the below link for more details.

In this article, we will talk about SASE component 1: Software-Defined Wide-Area Networking (SD-WAN)

The Traditional WAN

Function was to connect users at the branch or campus to applications hosted on servers in the data center. Typically, dedicated MPLS circuits were used to help ensure security and reliable connectivity. This doesn't work in a cloud-centric world.

Simply weren’t designed to handle the intensified traffic and connectivity demands of modern organizations. The need to connect countless objects, devices, people and applications compels a new approach to network design.

Legacy WAN Architecture Does Not Meet the Needs of the Business

• Too expensive compared with LTE & Broadband
• Backhauling all traffic—including that destined to the cloud—from branch offices to the headquarters introduces latency and impairs application performance
• Long setup time
• Complex to manage
• Degraded Cloud performance, As businesses adopt the use of SaaS and IaaS, applications in multiple clouds, IT is realizing that the user application experience is poor
• Traffic causes management complexity, application-performance unpredictability, and data vulnerability

What's SD-WAN:

SD-WAN is a virtual WAN architecture that allows enterprises to leverage any combination of transport services—including DIA, LTE and broadband internet services—to securely connect users to applications.

SD-WAN uses a centralized control function to securely and intelligently direct traffic across the WAN and directly to trusted SaaS and IaaS providers.

SD-WAN works by separating applications from the underlying network services with a policy-based, virtual overlay. This overlay monitors the real-time performance characteristics of the underlying networks and selects the optimum network for each application based on configuration policies.

SD-WAN Planes:

1. Management Plane - represents the user interface of the solution. Network administrators and operators perform configuration, provisioning, troubleshooting, and monitoring activity here.
2. Orchestration Plane - responsible for the Zero-Touch Provisioning process as well as first-line authentication, control, management information distribution. understand how the network is constructed and then share that information amongst other.
3. Control Plane - responsible for the implementation of control plane policies, centralized data polices, service chaining, and VPN topologies. It also handles the security and encryption of the fabric by providing key management.
4. Data Plane - is the hardware component that is installed at sites. They are responsible for bring up IPsec or GRE tunnels between the sites. Each router will form data plane connections to other routers within the SD-WAN overlay for the purposes of transporting user traffic

SD-WAN Benefits:

Performance benefits of SD–WAN

In comparison with traditional WAN, SD–WAN delivers enhanced performance from twin circuits. In the case of traditional WAN networks, one circuit is used actively while another one is employed as a backup circuit. This passive circuit is used when the main circuit fails. But in the case of SD–WAN, it uses both circuits actively for those applications requiring more than one circuit operation, which increases overall bandwidth and enhances the performance of the network. Furthermore:

1. It uses real-time application routing to improve application performance.
2. Using path conditioning, it makes poor-quality Internet act like MPLS. It eventually improves the performance of unstable links.
3. It can also improve the performance of MPLS without any class of service.
4. By measuring the best route and allowing the breakout of the local Internet, SD–WAN enhances cloud application performance.
5. It also applies suitable security and routing for proper recognition of the applications for enhanced performance.
6. SD–WAN allows applications like Microsoft Office 365 to easily administer and be secured by using DNS instead of an IP address.
7. It also improves the performance of IaaS and SaaS using virtual devices.

Deployment benefits of SD–WAN

SD–WAN also offers multiple benefits in the deployment of WAN. For large enterprises managing their WAN on their own, these are of vital importance.

1. SD–WAN reduces the time and costs associated with the deployment of WAN by using With the adjustment of IP addresses, it easily deploys each site with templates without any physical staging of devices, or at least minimum staging.
2. SD–WAN makes networks very easy-to-manage by maintaining consistency throughout the project. It also removes all carrier anomalies across all the networks, which further adds consistency in the network.
3. Many of the SD–WAN vendors claim their solution provides zero touch deployment. This means it does not require an engineer to install the system. In fact, it is self-installed.

Management benefits of SD–WAN

SD–WAN also offers a large range of in-life management benefits to large enterprises. Some of these benefits are described below:

1. In traditional WAN architecture, many of the changes were performed manually, which is time consuming and also has risks associated with it. SD–WAN reduces all the admin overheads of changes.
2. SD–WAN also improves application troubleshooting. In traditional WAN architectures, application troubleshooting in its true sense requires an understanding of the entire application path for effective troubleshooting. SD–WAN has improved the application of troubleshooting in comparison to traditional WAN monitoring systems. It troubleshoots the router-to-router tunnels of each customer site to where the application is hosted.

Security enhancement

SD–WAN provides a built-in security feature in almost all its solutions. Although many comprise basic VPN and firewall functions, which do not seem to be secure enough. But there exists many SD-WAN solutions that offer a wide range of features like IPS, AV, NGFW, encryption and sandboxing, which boosts security and prevents the system from regulatory violations, downtime, legal liabilities and data loss.

Reduced complexity

Sometimes, digital transformations lead to more complexity. This results not only in the form of poor network performance, but also an overburden on IT teams to manage the additional layers of complexity to the network. Furthermore, in traditional practices, onsite personnel are required to manage the IT infrastructure for all the remote branches. SD-WAN has simplified the WAN infrastructure by easing the load on overburdened IT teams. It uses broadband to automate monitoring tasks, close non-critical business applications and management of traffic via a centralized controller. In this way, it lowers the complexity and makes life easier for IT professionals.

Direct cloud access

Organizations across the globe are increasingly embracing cloud-based services. SD–WAN has enabled direct cloud access to remote branches, due to which, workers are capable of accessing cloud-based applications anywhere in the world, regardless of their location. It also does not over burden the central network by introducing additional traffic. Direct cloud access eliminates backhauling traffic by routing all the traffic through a data center coming from branch offices and the cloud. Prioritizing the business-critical applications, it also enhances the performance of cloud-based applications. That is why, in the days of the pandemic, working from home has become very easy to manage for major companies by enabling branches and working from home personnel to directly communicate with the Internet.

SD-WAN Leaders & Market Growth:

Dozens of vendors constitute the WAN edge market, which includes both traditional branch routers and software-defined WAN. The market is fragmented into well-known incumbent vendors, as well as several smaller suppliers. More than 70 vendors compete in the WAN edge market, according to Gartner estimates, and even more could enter the fray.

WAN edge infrastructure connects distributed business sites to resources in private and public data centers, as well as the cloud. The market for this technology is growing rapidly, largely driven by SD-WAN reference to Gartner.

In 2019, fewer than 20% of enterprises implemented SD-WAN, according to Gartner's recent Magic Quadrant for WAN Edge Infrastructure. By 2024, however, 60% of enterprises will have implemented SD-WAN.