SDN and SD-WAN

Question 1

What is SDN?

Answer 1

Software-Defined Network (SDN)
Decouples network control and forwarding functions for more flexible management.
Enables programmatically efficient network configuration and management.

Question 2

What are the SDN Layers:

Answer 2

Management plane
Engages directly with network applications.
Control plane
Hosts the SDN controller, orchestrating flow control and policy application.
Data plane
Consists of the physical and virtual network devices.

Question 3

What are the SDN Controllers

Answer 3

The central authority that manages traffic flow and policy enforcement across the network.
Can be a physical or virtualized device

Question 4

What are the NB and SB interfaces?

Answer 4

Northbound interface (NBI) - Connects the SDN controller with the applications; utilizes RESTful APIs for communication, enabling developers to program the network using high-level languages like Python and JavaScript.
Southbound interface (SBI) - Links the SDN controller with the network devices; OpenFlow is a predominant protocol here, facilitating the controller’s ability to direct network traffic.

Question 5

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

Answer 5

Extends SDN concepts to wide area networks, overlay network over large geographical areas.
Focused on delivering a high-performance WAN that uses multiple transport technologies.

Question 6

What are some of the SD-WAN components?

Answer 6

Overlay Network - Virtualizes WAN connections to connect different parts of the network over the internet or a private network.
Edge Devices - Sit at the perimeter of a network, providing connectivity and SD-WAN functionalities.
Controllers:
SD-WAN Controller - Oversees traffic routing, policy management, and the health of the SD-WAN connections.
Interfaces:
Management Interface - For SD-WAN configuration and monitoring.
Orchestration Interface - Manages and synchronizes policies and settings across the SD-WAN fabric.