What is SDN?

Software Defined Networking is a network architecture that can be totally controlled via software from a central location. SDN allows users to modify the behavior of any given technology. Its possible applications are many, such as Data Centre Scaling, Application deployment, secure IOT architecture and intent-based networking (IBN). The SDN operators can tune its performance to fit its distinctive needs. All SDN Control devices support use of the Application Programming Interfaces (APIs) instead of relying on individual controls physically located on hardware.

What is SD-WAN

SD-WAN is a comprehensive WAN solution that centralizes all management features such as orchestration, configuration and connectivity. The connectivity between the sites can be any or a mix of the following: MPLS, private layer 2 network, broadband Internet or 5G/LTE. Customers achieve greater flexibility and performance by centralizing control in the cloud. SD-WAN is offered the same way as a service to customers as cloud services. SD-WAN in simpler terms refers to SDN in the WAN, whereas SDN refers to both LAN and WAN services and is mostly deployed at Data Centres. SD-WAN supports networks that are spread out over a sizable topographical area.

SDN and SD-WAN can be differentiated in the way they are used. SDN is used by traditional Service providers and enterprise Data Centers. It offers on-demand services, low operational costs and improvements in network performance and scalability. Comparatively, SD-WAN is a cost-effective alternative to the traditional Multiprotocol Label Switching (MPLS) networks, providing connectivity for geographically dispersed locations in a cost-effective, scalable and secure way.

Both SDN and SD-WAN technologies branch from the same fundamental concept of managing and configuring a network using software, they have several architectural things in common, such as

• Centralized management or orchestration – the control plane
• Distributed data forwarding function – the data plane
• Application-driven traffic routing policies
• Virtualization
• VNF Support
• Both can utilize commodity x86 hardware

Below are the differences between the two technologies.

SD-WAN	SDN
Deployed in branch offices and data centers	Mainly used in data centers
Recent technology but maturing very rapidly	Technology has taken a long time to mature
Off-the-shelf x86 appliances – physical, virtual, cloud	Variations of commodity and specialized switching hardware
Savings come from using alternative WAN transport, infrastructure costs and improved operational efficiencies	Savings come from improved operational efficiencies