Software-Defined Networking (SDN) Overview

Traditional Networks

Control Plane: Each device (routers, switches) has its individual control plane.
- Responsible for decision-making on how to handle data.
- Comparable to players on a team making individual decisions without a central strategy.
- Drawbacks:
  - Difficult to dynamically make decisions as network conditions change.
  - Hard for network administrators to react promptly to high traffic volumes.

Central Controller: Acts as a central "brain" for the entire network.
- Communicates with each device's control plane.
- Guides the decisions of the devices.

Separation of Control Plane:
- Centralizes communication and decision-making.
- Increases efficiency in network management.
Data Plane:
- Executes decisions made by the control plane.
- In SDN, the central controller coordinates all devices for a strategic approach.
Dynamic Network Management:
- Changes to network policies can be done centrally.
- Reduces time and errors when updating strategies across devices.
Real-time Execution:
- Routing policies and data packet prioritization are dynamically managed by the central control plane.

OpenFlow Protocol: Facilitates communication between the controller and network devices.
- Ensures adaptability, troubleshooting, and efficiency in network management.

Network Virtualization: Enables the creation of virtual networks.
SDN Ecosystem and Industry Standards:
- Ensures compatibility and effective implementation.

Northbound APIs: Facilitate communication between the SDN controller and applications.
Southbound APIs: Facilitate communication between the controller and network devices.