Difference between SDN and SD-WAN

Last Modified: August 26, 2024

Table of Contents

Introduction

In the fast-paced networking world, two acronyms have been generating considerable buzz: SDN, also known as Software-Defined Network, and further advanced one that we will discuss in detail here is the SD-WAN, which stands for the Software-Defined Wide Area Network.

In this blog, you will understand the key difference between SDN and SD-WAN technology. This comprehensive guide will help you understand both these terms along with their purposes, components, and benefits. To gain a deeper understanding of these technologies and their practical implementation, consider enrolling in a Cisco SD-WAN training course.

Let’s see some technical difference between SDN and SD-WAN.

Difference between SDN and SD-WAN

The main difference between SDN and SD-WAN is that SDN is primarily concerned with controlling the network itself, while SD-WAN focuses on optimizing traffic flow across the network. Here are some other important differences:

Control Plane and Data Plane Separation: As in SDN, the control plane and data plane are separated. This centralizes the control and makes it easier to implement. SD-WAN also uses this separation of these planes, but in this case, the primary goal is applied to the different WAN connections.
Traffic Management: SDN offers direct fine-grained control for handling traffic within the network, thus enabling efficient traffic management and pathing. Through the introduction of policies, SD-WAN can offer certain priority to the traffic, with a view of allowing enough bandwidth for crucial applications.
Security Measures: There is another advantage, SDN permits for setting of security policies across the network from the single controller, so, it is easier to follow higher coherent security policy across the network. SD-WAN integrates security measures such as encryption and firewalls into the WAN to safeguard the data as it transmits between the different sites.
Performance Optimization: SDN is beneficial in improving the performance of the existing pathways within a network based on real-time conditions. This helps in the utilization of the network resources in an optimum manner and could reduce the network lag and increase the overall utilization of the network. On the other hand, SD-WAN aims to improve WAN performance by taking the right traffic path for an organization depending on factors such as latency, jitter, and packet loss. This is particularly helpful in instances where such a factor must be met, for example, in carrying out a VoIP or a video conference.

Before understanding more differences between SDN and SD-WAN, let us first understand What these technologies really are.

What is SDN?

SDN is a new technology of network management where the control layer that decides where data must be transmitted is separated from the forwarding layer that transmits data to the required place. These are the points that can help the network to be more centralized and flexible, where administrators can programmably configure, manage, and optimize the network resources.

Key Components of SDN

Controller: The brain of the SDN architecture, which communicates with both the applications and the network devices.
Southbound APIs: These are the protocols used by the controller to communicate with the network devices.
Northbound APIs: These allow communication between the controller and the applications.

How SDN Works?

As in traditional methods of implementing networks, all devices (specifically, routers and switches) make the decision independently to forward traffic. SDN concentrates the control in the SDN controller, which applies software to determine the routes that data has to follow throughout the network. Unlike distributed approaches where the behavior of a network is fixed because of the partitioning of work, this allows for real-time behaviors to influence a network’s architecture.

What is SD-WAN?

SD-WAN is a further evolution of the SDN concepts but applied to the WAN environment where the main task is to address and control end-to-end WAN connections between geographically dispersed locations, including branches and data centers. It uses software to manage the flow of the data over the WAN to ensure business and needed application traffic are accorded a high priority.

Key Components of SD-WAN

Here are the components of SD-WAN:

SD-WAN Edge: The devices or software that reside at the network’s edge (e.g., branch office routers).
Controller: Similar to SDN, the controller in SD-WAN manages traffic and policies centrally.
Orchestrator: Manages policies and provides a dashboard for network administrators.

How SD-WAN Works?

SD-WAN utilizes multiple connections like MPLS, internet, and 4G to direct the traffic according to the specified policies by the organization. The SD-WAN controller also has real-time visibility of the network state in an instance and decides on what path a given type of traffic should take. It also contributes to better performance, most importantly in running applications that require low latency, such as VoIP or video conferencing.

Now that you have a basic understanding of both SDN and SD-WAN, let us look into SDN vs SD-WAN.

SDN vs SD-WAN

Below, we have discussed the difference between SDN and SD-WAN in detail based on different factors.

Factors	SDN	SD-WAN
Core Purpose	SDN is mainly targeted at the internal network like data centers, cloud networks and so on, which offers management and control of the traffic flow.	SD-WAN is specifically aimed at the management and control of WANs most especially in links over long distances between different sites.
Deployment Scenarios	SDN is usually implemented in data centers and large enterprises since these are the areas that require dynamic and programmatic networks.	SD-WAN is applied in organizations having several branch locations in an effective and efficient means of connecting them.
Control and Management	Despite the centralized control feature present in both initiatives, the control provided with SDN is more specific, which extends to controlling the data plane in the network.	SD-WAN is less centralized than traditional WAN because it relies more on policies to transport data based on rules and real-time conditions of the network.
Flexibility and Scalability	SDN gives more agility at the granularity of the data center or cloud where it is easier to gain quick access to space and provisioning of network resources.	SD-WAN also provides options for connecting globally distributed locations and the company’s branches, for it will be easy to expand when more branches are established.

Now that you have a good knowledge of SDN vs SD-WAN, let us look at the different advantages that SDN and SD-WAN offer.

Advantages of SDN

Some of the advantages of using SDN are:

Enhanced Network Efficiency: SDN brings more effectiveness in the utilization of existing network resources because it provides a mechanism for deciding on how to route traffic. This can eliminate congestion and enhance the general performance of the network, especially in areas of high traffic demand.
Simplified Network Management: One of the features that makes the use of SDN preferable is that all the networks can be controlled by the central controller only. This makes things such as configuration, monitoring, and especially troubleshooting much easier, hence minimizing the operational workload on the IT teams.
Greater Control and Customization: SDN offers fine granularity on how the network behaves, this allows an organization to design their network to address specific requirements. It is most beneficial where stability, security and great performance are of great importance in the system.

Advantages of SD-WAN

Some of the advantages of using SD-WAN are:

Cost Savings on WAN Infrastructure: SD-WAN drives the cost of the WAN infrastructure down with the help of employing lower-cost broadband connections in addition to traditional MPLS circuits. It is much cheaper, and organizations can attain the same or even better performance.
Improved Application Performance: In this regard, SD-WAN has a feature of traffic prioritization where the applications most important to the business are granted the resources they need most. This can result in performance enhancement of VOIP, video streaming, conferencing and services that are cloud intensive.
Enhanced Security: The SD-WAN solutions come with integrated security measures such as encryption, firewalls, and intrusion detectors. This assists in securing data as it is transmitted through the WAN to minimize the likelihood of the data being intercepted significantly.

Now, we have covered all the difference between SDN and SD-WAN.

Frequently Asked Questions

Q1 – Is SDN the same as SD-WAN?

No, SDN and SD-WAN are not the same. SDN controls the entire network, while SD-WAN is a specific application of SDN that focuses on optimizing WAN connections.

Q2 – What are the benefits of SDN and SD-WAN?

Some of the benefits of SDN and SD-WAN are:

SDN: Better network flexibility and scalability, enhanced Security, better Network visibility, and reduced costs.
SD-WAN: Optimized WAN performance, better application experience, reduced bandwidth costs, and simplified network management.

Q3 – What do SDN, SD-WAN, and SDV all have in common?

SDN, SD-WAN, and SDV are all types of network virtualization solutions, managed through software control.

Q4 – What is the difference between SD-WAN and SD access?

SD-WAN focuses on wide area networks, while SD-Access focuses on local networks like Wi-Fi and LAN connections.

Conclusion

SDN and SD-WAN are two technologies that are familiar to most IT specialists. Still, by comparing them, any organization can decide which technology should be implemented. Hence, whether it is the case of enhancing the network density, minimizing the costs, or possibly promoting the application’s performance, both SDN and SD-WAN are replete with benefits that can help drive the desired digital change. In this blog, we have explained the basic difference between SDN and SD-WAN, along with their definition, components, and functioning.