What Is SD-WAN (Software-Defined WAN)? Definition, Solutions, and Benefits

Posted on September 1st, 2022.

Software-defined WAN or SD-WAN is defined as a virtual wide area network (WAN) that relies on software technologies – like internet-based communication tunnels, software-driven network encryption, firewall software, etc. – to operate a mid-sized to large-scale computer network spread across locations.

A software-defined wide area network (SD-WAN) uses software-defined technology and infrastructure. SD-WAN dissociates the networking hardware from the control mechanism and thus streamlines the WAN’s operation and management. Organizations that use SD-WAN solutions can build higher-performance WANs using inexpensive internet and at significantly lower costs than private WAN connection technologies such as multiprotocol label switching (MPLS).

SD-WAN solutions make it easier for organizations to manage firewalls and routers, upgrade software and firmware, virtual private networks (VPN), and remote clients through a centralized management interface. The centralized management control is used to securely and efficiently route traffic across the WAN directly to trusted providers such as software-as-a-service (SaaS) and infrastructure-as-a-service (IaaS). It also minimizes labor costs by cutting maintenance costs and lowers the cost of equipment.

Limitations of WAN and how SD-WAN addresses them

During the early years, WANs required backhauling of all traffic from branch offices to a data center where they applied advanced security services. Traffic between the source and data centers was based on complex routing protocols such as transmission control protocol (TCP/IP) addresses and control list tables. 

Ultimately, it leads to delays resulting in poor application performance, user experience, and huge costs due to expensive bandwidths. Users also had to incur expenses to install MPLS routers at each location. Performing upgrades on firmware or software took longer times due to network complexities. The network architecture was also not optimized for cloud infrastructure. The limitations of traditional WANs drove the change to a better SD-WAN technology that replaced MPLS.

SD-WAN is deployed in an organized way in branch offices and data centers. It is optimized for cloud infrastructure and associates cloud technology with mobile computing. It separates the data plane and control plane of the network. It has a centralized management interface where traffic is managed and monitored. It has a single management portal which reduces complexities and makes it easier to track applications, thus improving performance and operational efficiencies. 

By providing lower-cost infrastructure and transport costs, an organization can save. SD-WAN provides end-to-end encryption over the entire network, providing secure connections to its users. Additionally, SD-WAN can prioritize traffic on business-critical applications and route it through the most efficient pathway. 

How Does SD-WAN Work?

The main objective of SD-WAN is to connect end-users and the applications, notwithstanding the location of these end-users. SD-WAN drives traffic as per the business requirements of the application. These business requirements vary from the priority of the application to must-enforced security policies or application performance required. Usually, critical mission applications are given the highest priority. The networking approach may vary from MPLS to broadband to 4G LTE.

The SD-WAN architecture separates the control and management functions, applications, and WAN transport services. It has a centralized control plane that stores and manages all the data on the traffic and applications. The centralized control plane monitors and adapts traffic to suit the application demand and delivers the optimum experience. 

The following are features of SD-WAN that users should consider before choosing an SD-WAN solution model:

• Encrypted overlay network: Traffic over the entire network must be encrypted to avoid any cyber threats leading to data loss. It should also be policy-driven.
• Real-time monitoring: The chosen SD-WAN should be able to collect real-time data statistics.
• Endpoints: The chosen SD-WAN must connect with every endpoint from any application and software.
• Load balancing: This technique ensures that the bandwidth is efficiently utilized to manage several incoming and outgoing traffic requests.
• Resiliency: The chosen SD-WAN should support redundancy and failover features.
• Policy-based routing: Algorithms that use real-time statistics to find the most optimal paths for a specific application should be included.
• Data services independence: The SD-WAN should have the ability to connect to multiple stations with different categories of internet data services and hybrid deployments.
• Advanced security and VPN features: The chosen SD-WAN should ideally have advanced security features such as a next-generation firewall, a security web gateway, and advanced cyber threat protection.
• Mobility features: The SD-WAN should have mobility features such as access control, an advanced security parameter, and automatic ideal route selection that enable interactive interactions. 

Top 10 SD-WAN Solutions

SD-WAN allows organizations and small businesses to securely connect their users to applications by taking advantage of any combination of network services. When choosing the right SD-WAN solution providers, users should consider factors such as security, price, availability of hybrid wide area network (WAN) solutions, and the ease at which they can be deployed. The top 10 SD-WAN solutions include:

1. Cisco Meraki SD-WAN

Powered by Meraki, Cisco SD-WAN is a scalable, programmable, and open solution that allows users to connect to any application. It offers control, visibility, and real-time analytics to its users. Cisco SD-WAN offers cloud management services and it can also be deployed on-premise. It is integrated with capabilities that allow it to perform optimization of applications, unified communications, multi-cloud services, and security. 

2. Fortinet FortiGate SD-WAN

Fortinet FortiGate provides a secure networking approach that combines SD-WAN, advanced routing, and next-generation firewall (NGFW) to promote consistent security and network policies and reduce operational costs through automation, self-healing, and deep analytics. This also simplifies wide-area network (WAN) architecture by accelerating network and security convergence. Fortinet FortiGate SD-WAN offers improved multi-cloud application performance through multi-path control, application steering and identification. 

3. Oracle SD-WAN

Oracle SD-WAN provides users with simplified WAN management services such as SD-WAN, firewall, routing, and WAN optimization. It provides users with high bandwidth and inexpensive internet connections and delivers easy-to-deploy and manages the network. Oracle SD-WAN offers its users reliable, quality, flexible and secure services. With its high availability, users can enjoy faster applications and better networks. It also allows for safer migrations of applications into the public cloud. 

4. Citrix SD-WAN

Citrix SD-WAN combines cloud-delivered and comprehensive security with SD-WAN, analytics, and secure internet access. It has strong security at the WAN Edge, providing complete protection against all threats. Its Citrix cloud on-ramps feature provides flexible on-ramp options for any cloud access that simplifies multi-cloud transition. Citrix SD-WAN reduces network costs and increases agility. 

5. CenturyLink SD-WAN

CenturyLink SD-WAN unifies network management across different network types, creating an agile and responsive wide area network. It enables users access to bandwidth to leverage broadband connections for bandwidth-intensive applications. It provides users with data analytics and reports while offering performance-based application routing. CenturyLink SD-WAN offers a reliable solution that allows users to reduce operating costs for equipment and staff. 

6. Wanify SD-WAN

Wanify has partnered with VeloCloud to deliver VeloCloud SD-WAN. It manages end-to-end processes and improves network performances by combining multiple connections for its users. It supports network agility and application growth by offering optimized access to cloud applications and data centers. It routes application traffic through efficient routes after gauging the real-time performance of the network. Wanify SD-WAN provides customer support and offers a secure and customizable solution for its clients. It also manages carriers for its users. 

7. Palo Alto Networks Prisma SD-WAN

Palo Alto Networks offer SD-WAN services through Prisma. It provides networking and security in a single platform. It enables app-defined policies for SD-WAN that eliminate network problems, increase bandwidth, and simplify management for its users. Palo Alto Networks Prims SD-WAN allows users superb control and connection options along with supporting machine learning and automation. It also provides users with router modernization and cloud migration. 

8. Exinda SD-WAN

Exinda SD-WAN provides businesses with a stable, secure, reliable, and cost-effective solution. It combines and manages up to 12 internet kinds of transport from local service providers. The Exinda SD-WAN network router monitors, detects, and adapts to fluctuations from internet service providers and also monitors traffic changes. It automatically solves network problems, thus avoiding interruptions to internet services and applications. It allows users to add bandwidths to their networks when they need to increase network capacities. Integrating Exinda SD-WAN and Exinda network orchestrator enhances the ability to accelerate applications to better performance. 

9. Masergy SD-WAN

Masergy SD-WAN leverages its secure edge network with built-in Fortinet security. It provides clients with end-to-end visibilities and uses artificial intelligence for IT operations (AIOps) to analyze networks and make recommendations to improve reliability. It uses AIOps and shadows IT discovery tools to build overlays to fit networks. It customizes rules to meet network and application requirements. Masergy SD-WAN allows for co-managing with its users to streamline inefficiencies. 

10. Aryaka SD-WAN

Aryaka SD-WAN has a built-in WAN optimization that guarantees application performance for this feature-rich platform. Aryaka SD-WAN service doesn’t need the installation of complex appliances or network management software as it is a remote-based cloud system. Users can connect to it through virtual private networks (VPN). Aryaka SD-WAN provides insightful analytics in a secure platform that offers a multi-cloud networking service. It provides reliable throughput, real-time visibility, and single-day deployments for new technology. 

Benefits of SD-WAN

The global software-defined wide area network (SD-WAN) market size is expected to increase exponentially from $1.9 billion in 2020 to $8.4 billion by 2025. This figure represents a compound annual growth rate (CGAR) of 34.5%, as per research by MarketsAndMarkets. These figures express an increasing appetite for SD-WAN solutions from enterprises due to a slew of business benefits. These include:

1. Improved security

In the recent past, business enterprises and other organizations have embraced advanced technologies to gain an edge against their competitors in the market. However, its adoption has brought on its fair share of problems in the form of cybercrime.

Most SD-WAN solutions offer basic built-in security features like firewall and VPN functions that improve security for their users. Additionally, users looking for advanced security features can look for SD-WAN solutions offering features to prevent data loss, downtime, and legal liabilities. Popular SD_WAN solutions include next-generation firewalls (NGFW), intrusion prevention systems (IPS), encryption, and sandboxing capabilities.

2. Greater network agility

Users can configure SD-WAN to steer their business traffic through the most efficient route by prioritizing real-time services such as voice over internet protocol (VoIP) and business-critical traffic. SD-WAN, through its flexibility, allows users to vary bandwidth access via any local internet provider to promote increment in speeds to match real-time demand. Varying bandwidth using deduplication and compression also helps in reducing the total cost of ownership (TCO). 

SD-WAN allows for bandwidth capacity to be scaled up or down through the direct addition of internet broadband connectivity. A single logical link can be formed when multiple WAN service types, such as direct internet or private multiprotocol label switching (MPLS), are bonded together.

Other optimization techniques that SD-WAN employs to improve network agility include data de-deduplication, data compression, and secure sockets layer (SSL).

3. Reduced operational costs

According to a 2018 forecast survey by IDC Research, up to two-thirds of respondents expect to save 5-19%, while a quarter expect upwards of 39% savings when using SD-WAN technologies. SD-WAN technology allows for self-managed procedures and automation, which enables organizations to reduce the number of external IT experts required to carry out periodic tests and maintenance, thereby proving to be cost-effective.

SD-WAN aggregates multiple direct-to-internet (DIA) lines for WAN connectivity, thus reducing the overall cost for bandwidth as it requires less network hardware. Organizations can also easily set up new branches online at any location at less time and cost.

4. Reduced data complexity

As small businesses use more technology solutions such as local, edge, and cloud-based applications, network complexity becomes a common problem. This is due to competition for limited bandwidth, which leads to poor network performance. It might also necessitate hiring more IT specialists on-site to manage local IT infrastructure, leading to increased costs. SD-WAN provides a solution through monitoring and alerting the performance of different data types to ensure enough bandwidth is allocated. Users can configure SD-WAN to prioritize critical traffic through the most efficient path to its destination to improve performance.

5. Centralized management

SD-WAN is usually managed through a centralized management interface that monitors it and manages traffic. From a single management portal, paths to applications are allocated according to criticality, new sites are provisioned, software and firmware upgrades are performed, and users can flex bandwidth from this point. Using a centralized management plan helps to reduce complexity and makes it easier to track applications and their performances from a single zone.

6. Enables cloud usage

Organizations are gradually adopting cloud-based services. SD-WAN enables users to access the cloud remotely without burdening the core network with additional traffic to manage and secure. This may promote cost savings for organizations looking to cut down on office space, equipment and rent as employees can work remotely. The need for additional IT experts to manage and secure data traffic is also minimized. 

SD-WAN solutions improve cloud applications’ performance by emphasizing business-critical applications and allowing them to communicate directly to the internet. SD-WAN guarantees quality and optimizes data, followed by directing network traffic along the most efficient routes.

7. Supports automation and orchestration

Even with the gradual increase in the popularity of cloud-based resources, organizations still have to wait for weeks or months to set up new WAN circuits or managed service providers (MSPs). A fully managed cloud-first WAN service could offer cloud-based network offerings comparable with other cloud services through orchestration and automation. 

This feature would promote quick turn-up of newer locations globally and services bolstering enterprise flexibility. It would also facilitate troubleshooting and increase the visibility of enterprises.

8. Paves the way for predictive analytics

SD-WAN technologies offer predictive analytics enabling IT specialists to navigate potential outages and mitigate any other potential issues. SD-WAN monitors the system in real time and provides data analytics to determine and predict any problems. This ability helps to reduce resolution time for organizational IT troubleshooting, lowering TCO, and maintaining peak performances at all times. This leads to increased productivity in organizations and decreasing costs, as IT experts are not always required to be on-premises. In case a problem arises, they can quickly identify and fix the issue.

Takeaway

Software-defined wide area network is a crucial enabler for enterprise digital transformation. It is highly extensible so it can integrate new-age security technologies like SASE with existing network infrastructure. It can also simplify IT operations by paving the way for AIOps alongside network management. That’s why it is vital to understand the working and potential benefits of SD-WAN to prepare for your adoption journey. 

Source: Spiceworks