11) SDN

What is SDN?

Control plane separated from data plane

What is key idea of SDN?

Centralized control of network

What is data plane?

Packet forwarding and processing

What is control plane?

Computes forwarding decisions

What is management plane?

Configures and manages network

What does data plane do?

Match headers and take actions

What does control plane do?

Compute paths and routing

What is forwarding table?

Rules for packet forwarding

What algorithm used in routing?

Dijkstra shortest path

What problem in traditional networks?

Complex and hard to manage

What causes complexity?

Many independent control mechanisms

What is indirect control?

Changing configs to influence behavior

What is uncoordinated control?

Routers update independently

What is SDN benefit?

Simplifies network control

What is Network OS?

Maintains global network view

What does Network OS do?

Controls forwarding devices

What is control program?

Uses global view to configure network

What is forwarding abstraction?

Standard way to define forwarding rules

What is OpenFlow?

Protocol between control and data plane

What is flow table?

Set of match action rules

What is match action?

Match header then perform action

What actions in OpenFlow?

Forward drop modify send to controller

What is SDN advantage?

Programmability and flexibility

What is virtualization in SDN?

Abstract network into logical view

What is SDN driver?

Cloud and data center needs

What is B4?

Google private WAN using SDN

What is SDN goal?

Centralized traffic engineering