What Is SD WAN And Best SD-WAN Solutions For 2024

This tutorial explains what is SD WAN, its benefits, working, architecture, etc. Also, learn about different SD-WAN solutions:

The business world is dynamic and ever-growing and so are business needs. Rapidly moving market trends are a major factor creating a requirement for additional bandwidth, and greater dependency on the availability of network and quality.

The last decade has witnessed a wave of up-gradation in wide-area networks and one such breakthrough in technology is called SD-WAN. It is not an alien term for businesses spread across vast geographical areas and is often used to manage internal online transactions.

In this article, we will understand more about SD-WAN and the benefits of this technology and closely understand its working.

Let’s get started.

What Is SD-WAN

SD-WAN is an acronym that represents a Software-Defined Wide Area Network. This is used by companies to manage their network across vast geographical regions. It is a very useful technology that assists in creating a link between the central network and various other branch offices and data centers.

The term SD-WAN is a mix of two terms- SDN- Software-Defined Network and WAN- Wide Area Network. Let us understand how this works.

SDN refers to a cloud computing technology that is primarily useful for the internal data centers based at the headquarters. The key purpose of this approach is to help network administrators to ensure a quick response and centralized control to efficiently cater to business requirements.

When enterprises want to connect across large geographical regions, WAN is used. WAN is the network connection between the data center and branches in remote locations. It contains site to site Multi-Protocol Label Switching (MPLS) and hub-and-spoke structure which helps to connect headquarters and branches.

A combination of SDN and WAN gives us SD-WAN. It has the ability to handle the entire WAN spread across vast geographical locations through a centralized cloud-based location.

SD-WAN architecture is a perfect combination of SDN (architecture) and WAN (technology). It is a revolutionized solution and can also be called the “digital transformation” of organizations as they move from WAN to SD-WAN.

WAN architectures showed traces of increased delays and resulted in a lag in the overall performance of the network to cloud services. The adoption of SD-WAN is a fundamental change in the way of communication for enterprises. It connects headquarters data centers with of branch locations with the help of the cloud and the Internet.

In comparison to MPLS WAN, SD-WAN keeps the management of network, traffic, and other functions of monitoring completely separate from the hardware. Also, there is no contract that binds the enterprise with one service provider. Hence, this technology is extremely flexible and can support many carriers.

It is proved to be a one-stop solution for organizations and gained popularity by providing quick, expandable and flexible networking solutions. It also costs benefits as the overall cost of an upgraded experience of an application is reduced.

Architecture

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At the inception of building SD WAN architecture, an organization needs to have an absolute clear objective because this is an amalgamation of new and old technology. The process of replacement of each device like a router, controller, etc. should be precise keeping the vision in mind.

As depicted in the above image, SD-WAN introduces centralized control and management of over a thousand routers. This allows quick and simple modification of all routers and WAN connections to the enterprise. This was a serious limitation of traditional WAN where everything was controlled by the data center and the process of routing was complicated.

In a complicated traditional WAN architecture, all branches were first connected to a data center, and the data center was connected to the cloud. In the event of failure of even one leased line, there is a drop-down of traffic across the network.

This technology provided a simple solution to this complicated architecture by creating a direct connection of individual branches with the data center and cloud. In this setup, if any leased line fails, it redirects routes without impacting other lines.

As depicted in the image above, MPLS, broadband, and 4G LTE are individually in operation and enterprises can reap benefits without worrying about latency or network failures.

Let us also understand the types of SD-WAN architecture:

#1) On-Premise only

• This architecture applies only to enterprise websites that are connected using an SD WAN box or a router.
• No connection with cloud gateway.
• Traffic is managed in real-time and is limited to multiple enterprise sites only.
• Suitable for organizations with in-house applications and do not have a cloud-based infrastructure.

#2) Cloud-enabled

• SD-WAN box connects to a cloud or a virtual gateway.
• Benefits of on-premise architecture like load balancing on multiple circuits and real-time management of traffic along with the add-on advantage of improved performance and reliability of cloud infrastructure.
• Direct connection between cloud gateway and cloud service providers like Office 365, AWS, Dropbox, etc.
• In the event of an Internet drop, the session on the cloud still remains active. Also, in the case of secondary lines, SD-WAN successfully routes the cloud application on this secondary line, and the session is not impacted.
• This solution is perfect for organizations that employ a large number of cloud-based applications like Office 365, AWS, etc.

#3) Cloud-enabled plus backbone

• SD-WAN solution consists of an SD-WAN box that creates a connection between the website of the organization and the nearest Point of Presence (PoP) of the provider.
• It serves as additional support where the traffic is routed to the private fiber-optic network of this provider.
• Routing of traffic to SD-WAN provider’s private network gives benefits of reduced latency and packet loss.
• Overall performance of the network improves.
• This additional support, also called “backbone” is also connected with major cloud providers like Office 365, etc. This provides overall improved performance of cloud applications as well.
• This architecture type is suitable for those organizations which are in the process of removing MPLS networks and also have real-time network applications.

Suggested Reading =>> Top SD-WAN Vendors

Working

The first step in the formation of SD-WAN is when encrypted tunnels, also called overlay, are established across sites. Each site has SD WAN devices that are connected to the local networks.

As this connection is established, the SD WAN devices download the pre-defined configurations and other policies related to traffic. This is the time when tunnels are established either with each other or with a point of presence. This connection depends on the architecture.

It manages the routing and control of traffic. Routing of outbound traffic is done through an optimum path which is based on the policies of the application and traffic conditions at that point in time. In case of failure of any last-mile connection, it can automatically move to an alternate connection. This is possible due to the policies which were pre-configured and helped to manage the load of traffic.

Hence, we know that management based on policies is the major driving force in the case of SD-WAN. It is these policies that are critical in the selection of path and is able to divert and steer traffic on the basis of priority like the quality of service that it carries.

In order to meet specific business requirements or to improve performance, several policies can be created. An example of this is when priority has to be granted to packet transmission for VoIP.

Benefits

There are many benefits that have made it a popular choice for many enterprises. Some of these benefits are listed below:

• Simple to use: One major benefit for IT professionals is that it is simple and allows them to centrally control the entire WAN through one interface. It also has a zero-touch provision that allows the upgrade of the network to spread across the enterprise within a few minutes. It ensures increased cost and time efficiency by eliminating technicians who carry out expensive and time-consuming installations at multiple locations.
• Better visibility for IT Managers: IT Managers can get better visibility and control through a centralized interface. Traditional networks lacked the precision to provide detailed insights regarding networks and the behavior of applications. It provides a solution to this problem by ensuring a clear view throughout the network including the local branch, cloud, and headquarters.
• Cost efficiency: It is a cost-effective solution as compared to old hub-and-spoke networks due to the elimination of routers and other network equipment at locations. Also, there is no need to dispatch techs for the installation and maintenance of local networks. For many enterprises, the cost of MPLS circuits is unaffordable. Estimates suggest that the total cost of SD-WAN, which includes hardware, software, and support, is two and a half times less compared to traditional WAN architectures.
• Higher Performance: This technology has proved to have shown improvement in application and network performance. This has been possible due to dynamic bandwidth allocation which allows data to travel across many different channels simultaneously with the quickest routes. Bandwidth control on the basis of critical and non-critical applications is also improved.
• Reduced downtime: It also provides a single interface for the management of the entire network. This ensures quick troubleshooting and thereby leads to reduced downtime. Integration of several WAN connections and ISP, managing an event of failure of one of the paths is seamless. This is unlike in the case of MPLS networks where there is no failover to an alternate connection.
• Reliability: This technology not only provides optimized access to the cloud but provides remote access to the resources on site. This also helps to increase reliability for cloud-based applications like SalesForce and Microsoft Office 365.
• Flexibility: It also is a solution to be free from being locked in contracts with a particular service provider. It allows the freedom to switch between carriers, and choose a mix of different carriers thereby creating hybrid SD-WAN or MPLS networks.

Well, aren’t the benefits mentioned above enough to make this technology the most suitable choice for enterprises? Like every coin has another side, SD-WAN also has some limitations.

Limitations

These are:

• The benefits of SD-WAN are limited to accessing applications that are cloud-based in most cases. There is limited or no on-site security functionality that is provided.
• It primarily requires the IT department of the enterprise to carry out the planning, designing, implementing, and maintaining operations on its own. This makes it imperative to have teams who are capable of building and maintaining this solution. The cost of outsourcing the maintenance and troubleshooting of this solution can be very expensive.
• This technology also has limitations in terms of slow performance. While connecting to the cloud may be easier but there could be cases of packet loss even after that. This can be a serious limitation, especially for enterprises in digital business.

Here are a few points of comparison between MPLS and SD-WAN which must be considered before making a choice between one of these technologies.

MPLS vs SD-WAN

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Note: In the above image PE refers to Premise equipment.

The infrastructure of SD-WAN is virtual. As a result, the network functions, which otherwise run on network infrastructure, become virtual and can be used as software on the commodity hardware. MPLS, on the other hand, is hardware-based.

SD WAN Solutions

While there are a number of software in the market providing solutions for enterprises, below is a list of some top software.

#1) Raksmart

RAKsmart offers SD-WAN solutions across more than 200 PoPs globally. With the help of this solution, you’ll be able to establish connections with all public clouds anytime, from anywhere rapidly. You can also orchestrate data synchronizations across multiple data centers and clouds using this service.

#2) Cisco SD WAN

Cisco SD-WAN enables users to centrally control and manage from a single dashboard. It makes the process of monitoring and operating extremely simple. It provides benefits of both worlds as it can be deployed at a premise or can even be cloud-managed. It is a comprehensive solution providing advanced analytical features and the ability of multi-cloud connectivity.

Website: https://www.cisco.com/c/en_in/solutions/enterprise-networks/sd-wan/index.html

#3) Cisco Meraki SD WAN

Cisco Meraki is a popular SD-WAN solution available for all MX security appliances. It offers simplified, reliable, and secure solutions specifically for applications that are latency-sensitive and mission-critical. Suitable for applications like VoIP, Salesforce, and Office365. Its web-based dashboard provides quick insights regarding WAN and its access to live in-built tools.

This solution can provide centralized control and visibility of usage of both internal and external applications.

Website: https://meraki.cisco.com/products/security-sd-wan/

#4) Oracle SD-WAN

The Oracle SD-WAN is a reliable and high-performing solution for business-critical services. This solution promises to drastically bring down the operational burden of monitoring of enterprise network. It ensures a safe and secure network across clouds and data centers.

Website: https://www.oracle.com/industries/communications/enterprise-communications/products/sd-wan-edge.html

#5) CATO NETWORKS SASE cloud

It is the world’s first SASE platform which is known to have integrated SD-WAN and network security to form a global cloud-native service. It offers easy migration from MPLS to SD-WAN and connectivity is optimized across premise and cloud applications.

Website: https://www.catonetworks.com/cato-sase-cloud/

#6) VeloCloud

VeloCloud is an excellent solution that ensures its users have secure and reliable access to cloud applications from any location. This solution also includes cloud-based gateways as well as an orchestration platform. Its structure helps to eliminate those overheads that are otherwise an absolute mandate to maintain these components.

Website: https://sase.vmware.com/sd-wan/architecture

#7) Citrix SD-WAN

Citrix SD-WAN is a comprehensive solution that has been consistent in giving an increased performance for SaaS, cloud, and virtual applications. It provides the benefits of increased swiftness and lowered network costs, along with high-end visibility to monitor network performance.

Website: https://www.citrix.com/en-in/products/citrix-sd-wan/

#8) Cisco Adaptive Security Visual Appliance (ASA)

Cisco ASAv is an extremely popular solution that has strong VPN capabilities. Its prime features include providing support for site-to-site VPN, remote-access VPN, and clientless VPN functions. The solution enables a smooth and simple process of management throughout ASAs, both virtual and physical. The process of deployment, managing, and tracking of running applications is made simple with Cisco Smart Software Licensing.

Website: https://www.cisco.com/c/en_in/products/security/adaptive-security-appliance-asa-software/index.html

#9) Aryaka Networks

Aryaka, being the Cloud-First WAN Company, offers innovative solutions that are agile and simple for the customer’s network. It offers SD-WAN as a managed service and includes connectivity, application, security, and cloud networking solutions.

Website: https://www.aryaka.com/

#10) Wanify SD-WAN

Wanify is also a popular SD-WAN solution that is flexible and helps customers avoid the additional effort of approaching a carrier for SD-WAN. It is capable of managing end-to-end processes and improves the performance of the network by integrating multiple connections. It gauges the real-time performance of the network before routing application traffic. Wanify offers a safe, secure, and customizable solution.

Website: https://www.wanify.com/

Frequently Asked Questions

Conclusion

In this article, we have discussed what is SD-WAN along with the benefits can be extremely beneficial for an enterprise. However, whether an enterprise should implement SD-WAN solutions or not depends largely on the resources available to an enterprise to maintain and support the solution.

Further Reading =>> Paid And Free Network Monitoring Tools 

One of the other points to consider is to ascertain the needs of the employees and their location. Do the employees often work on the cloud or do they need to access on-site data?

We hope this article will benefit readers with some insights on SD-WAN and help them make a viable choice of network solutions.