Software Defined Networking (SDN)

- Overview

Software-defined networking (SDN) is a network architecture where the control plane (decision-making) is separated from the data plane (data forwarding), allowing network management to be centrally controlled through software applications, instead of relying solely on dedicated hardware devices like routers and switches, providing greater flexibility and programmability for network configuration and management. 

Essentially, SDN lets you manage your network using software rather than just hardware settings.

Key features about SDN:

• Centralized control: A software controller acts as the "brain" of the network, making decisions about how data is routed across the network.
• Abstraction: The controller abstracts the underlying hardware details, allowing administrators to manage the network using a unified interface.
• Programmable: Network configurations and policies can be defined and implemented through software applications using APIs.

Benefits of SDN:

• Improved agility: Enables quick network changes and updates through software-based configuration.
• Simplified management: Centralized control simplifies network operations and troubleshooting.
• Cost efficiency: Potentially reduces hardware costs by utilizing commodity hardware and optimizing network usage.
• Scalability: Allows for easier scaling of the network to meet changing demands.

Please refer to the following for more information:

• Wikipedia: Software-defined Networking (SDN)

- Traditional SDN Architectures

A software-defined network (SDN) architecture (or SDN architecture) defines how a networking and computing system can be built using a combination of open, software-based technologies and commodity networking hardware. 

Software-defined Networking (SDN) is an architecture designed to make networks more flexible and easier to manage. SDN enables centralized management by abstracting the control plane from the data forwarding functions in discrete network devices.

SDN is cloud-based software that allows the network to be managed from a central point. The key is virtualization, which allows the software to run independently of the hardware. It will respond automatically, and IT staff can see all problems from a single location and troubleshoot more easily.

SDN architecture separates the SDN control plane and the SDN data plane of the networking stack. 

The SDN architecture provides a centralized, programmable network and consists of the following:

• The controller is the core element of the SDN architecture, enabling centralized management and control, automation, and policy enforcement across physical and virtual network environments
• Southbound APIs that pass information between the controller and individual network devices such as switches, access points, routers, and firewalls
• Northbound APIs that pass information between the controller and applications and policy engines to which the SDN appears to be a logical network device

- Software-Defined Wide Area Network (SD-WAN)

SD-WAN, which stands for Software-Defined Wide Area Network, is a networking technology that uses software-based control to manage and optimize network traffic across multiple WAN connections, like different Internet service providers or dedicated lines, providing a more flexible, scalable, and cost-effective way to connect geographically dispersed locations compared to traditional WANs. 

Key features about SD-WAN:

- Next-generation SDN (NG-SDN)

Next Generation SDN (NG-SDN) refers to an advanced version of Software-Defined Networking (SDN) that leverages newer technologies like programmable networks and verification theory to provide greater network control, flexibility, and the ability to dynamically adapt to changing application needs. 

Essentially turning the network into a more programmable and verifiable resource for operators and developers; allowing them to define network behavior top-down rather than being limited by pre-configured hardware capabilities. 

Key features about Next Generation SDN:

• Enhanced programmability: NG-SDN allows for more granular control over network behavior through advanced programming interfaces, enabling customized network configurations tailored to specific applications.
• Verification and validation: NG-SDN incorporates mechanisms to verify and validate network behavior, ensuring that the network functions as intended and meets security requirements.
• Zero-touch configuration: NG-SDN aims to automate network configuration and deployment, minimizing manual intervention and speeding up provisioning.
• Open source foundation: Many NG-SDN implementations utilize open-source technologies and standards, promoting wider adoption and collaboration.
• Cloud-native approach: NG-SDN often integrates with cloud computing platforms, allowing for scalable and distributed network management.