Transitioning from Traditional Networks to Software-Defined Networks (SDN)

March 18, 2020

A few industry-recognized practices are described below. Although these practices are not written in stone and many organizations may have different approaches, this article provides a general overview of the advantages and challenges around transitioning to a Software-Defined Network (SDN).

What is a Software-Defined Network ?

A Software-Defined Network refers to a network that is controlled by a central entity or software that is used by all the network hardware. An SDN separates the data plane from the control plane and puts the control in the application layer rather than the network layer. It offers the benefits of reduced costs, enhanced security, greater flexibility, easier configuration, prevents vendor lock-in, and many other advantages over a traditional network.

Preparation

For an organization to effectively migrate to a software-defined network, IT administrators should embrace the advantages of SDN over a traditional network. Understanding the OpenFlow protocol, SDN controllers, and how to configure devices to communicate with the controller will help ease the transition process.

Pre-Migration

Studying the migration use cases of big companies like Google, who have already shifted to SDN, can help gauge the challenges when transitioning to SDN. Some potential challenges may include network outages, disruption of critical network equipment, etc. Along with this, considering the security aspects of shifting to SDN is also a key step. Having a physically decentralized but logically centralized controller (also known as a single point of control) is the ideal way to ensure security and redundancy.

Migration

We need to consider the different vendors which offer the software and support needed to shift from a traditional network. There are several open-source vendors as well as enterprise software options. Choosing the right vendor will depend on what type of requirements you have for your network, along with the cost that is allocated to this transition process. The transition process should start small, which can then be scaled up to the level of your organization’s network. Shifting the entire network will increase the risk of things going wrong, which will take more time and resources.

Post-Migration

Once you have successfully transitioned even a small part of your network to SDN, comparing the parameters like performance, the operation cost of the new SDN, and the old legacy network will give you an idea of how successful the transition was. Having a rollback plan is also mandatory in the unlikely event that SDN is not suitable for your organization.

In conclusion, SDN is the way forward to survive in this technology-first world. An early shift will be beneficial, as the organization will have more streamlined services. SDN is an inexpensive option compared to maintaining existing data centers.


About the author

Aakash Rawal is a first-year graduate student pursuing a Masters in Technology, Cybersecurity and Policy at the University of Colorado Boulder. He is interested in Network Automation, DevOps and Network Security.