What is SDN?

SDN is Software Defined Networking, which is an approach of network management, managing our devices centrally. This will give us easy monitoring and easy troubleshooting of distributed network devices. By removing the control plane of network devices, SDN will attempt to centralize the network intelligence in our network component. Having one or more controllers in the SDN control panel, we take it as the brain of the SDN Network.

It uses API (Application programming interface) to program your network intelligently through centralized control. The underlying hardware (network devices) and associated technologies are still in there, but we can program them centrally. As a result, you can continuously and easily manage and troubleshoot your entire network with flexibility and speed.

API (Application programming interface)

API is software in between two applications and two computers that allows them to communicate with each other. An API is a set of rules that explain how two computers or applications can communicate with each other. API is in between application and web server and acts as an intermediary layer that handles data between systems.

Why do we need SDN?

Software Defined Networking is important because it gives your network operators a new way to design, build and operate the WAN networks of your organization with zero touch provisioning. In addition to centralizing and simplifying the control of network management, SDN offers the following advantages: –

  1. Traffic programmability.
  2. Capacity to generate policy-driven network supervision.
  3. Ability to implement network automation.
  4. With the help of SDN, we can achieve extremely fast failover.

Here are several primary advantages that SDN offers

  1. Centralized network provisioning: – SDN helps you to consolidate your network management by giving a unified perspective on the entire network. SDN can also speed up service delivery and boost agility in provisioning virtual and physical network devices in a central location.
  2. Lower operating costs: – Having efficient administration, server utilization improvements, and improved virtualization control, SDN can help to cut operating costs. Because many regular network administration-related tasks and issues can be automated and centralized.
  3. Holistic enterprise management: – SDN helps you to adjust your network device configuration with no impact on your current network. Also, unlike Simple Network Management Protocol (SNMP) the management of physical and virtual switches and network devices that are from a central controller.
  4. More granular security: – By establishing a central control point for regulating security and policy information for your enterprise network, the SDN controller quickly becomes a boon for your network.
  • Hardware savings and reduced capital expenditures: – By following the instructions from the SDN controller, older hardware can be repurposed while less costly hardware can be deployed to optimal effect. This process allows a new device to become a white box.
  • Consistent and timely content delivery: – One of the biggest benefits of SDN is the ability to manipulate data traffic. It is important to have the quality of service for Voice over Internet Protocol (VoIP) and multimedia transmissions services if you are able to direct and automate data traffic. SDN also helps you with steaming higher-quality videos.

Disadvantages of SDN

  1. It requires a change in the entire network infrastructure to implement SDN protocol and SDN controller. It requires a complete reconfiguration of the network. This increased cost due to reconfiguration.
  2. Staff Needs to be trained.
  3. A new management tool needs to be procured and everyone should be trained to use it.
  4. Security is a big challenge in SDN.

Architectural Component of SDN.

SDN Application: – SDN Applications are the programs that clearly, immediately, and programmatically communicate with their network equipment as per requirements and desired network to the SDN Controller via API (Application programming interface). The applications can build an abstracted view of the network by collecting information from the controller for decision-making purposes.

SDN Controller: – The SDN controller is a logical entity that receives instructions from the SDN application layer and relays them to the networking components. The controller also extracts information about the network from the hardware devices and communicates back to the SDN applications of the network, including statistics and events about what is happening.

SDN Datapath: – The SDN networking devices control the forwarding and data processing capabilities for the network. This includes the forwarding and processing of the data path.

SDN Control to Data-Plane Interface (CDPI): – The SDN CDPI is the interface that is defined in between an SDN Controller and an SDN Datapath, which provides at least.

  1. Programmatic control of all forwarding operations
  2. Capabilities advertisement
  3. Statistics reporting
  4. Event notification

SDN Northbound Interfaces (NBI): – SDN NBIs (Northbound Interfaces) are interfaces between SDN Applications and SDN Controllers and typically provide abstract network views and enable direct expression of network behaviour and requirements. This may occur at any level of abstraction (latitude) and across different sets of functionalities (longitude).

Application of SDN

  1. SD-LAN: – (Software defined local area network): Software-defined local area network (SD-LAN) decouples control plane management plane, and data planes to enable a policy driven architecture for wired and wireless LANs (Local Area Network).

Example SD-LAN is Cisco Identity service engine (ISE) and Network access control (NAC).

  • SD-WAN: – Software-defined wide network (SD-WAN) separates the control and data plane of the WAN network devices and enable a degree of control across multiple WAM element like physical and virtual.

A local area network (LAN) is a computer network in which we connect computers within a limited area such as a home, office, laboratory, university campus so that computers and users can communicate with each other.


A Wide area network is a computer network in which we connect multiple LAN networks so that computers and users in that network can communicate with each other.

In this blog, we learned what is SDN definition, the advantage disadvantage of SDN, the application of SDN, and the structural component of SDN. Zindagi Technologies has been providing security services for many years which makes us one of the trusted IT Consulting companies as we deliver what we promise. If you want security services, then give us a call or WhatsApp us on +919773973971. You can also drop us an email.

Yuvraj Kumar
Senior Consultant Network Security

Comments (3)

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    Hairstyles Women
    September 9, 2022

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    Krystyna Wassermann
    September 15, 2022

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    Alemu Gudeta (Ifargan)
    January 27, 2023

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