Software Defined Networking

1. Overview

Software Defined Networking (SDN) is a networking paradigm that separates the control plane from the data plane.
- Control Plane: Responsible for decision-making processes about where traffic is sent.
- Data Plane: Handles the actual forwarding of packets according to decisions made by the control plane.
SDN allows network administrators to manage network services through abstraction.
- Centralized management of network configuration.
- Simplifies network design and operation since the control plane is logically centralized.

SDN Controller: The central system that governs the behavior of the network.
Northbound Interfaces (APIs): Interfaces allowing interactions between the SDN controller and the applications/processes.
Southbound Interfaces (APIs): Interfaces enabling communication between the SDN controller and the network devices/switches (e.g., OpenFlow).

Potential security risks due to centralized control.
Complexity in the initial transition from traditional networking to SDN.
Performance bottlenecks if the controller fails or the network is overly centralized.

SDN and Cloud Computing: Both aim for resource optimization and improved service delivery, and they complement each other by enhancing network management in cloud environments.
Security Concerns: Centralization in SDN introduces a single point of failure, making thorough security measures essential.
Technical Evolution: Movement towards more decentralized models like distributed SDN to mitigate some of the centralization risks.