---
title: "20-network-layer-control-plane"
aliases: 
tags: 
- cosc203
- lecture
---

# per-router control vs SDN
## per router
- each router runs a routing algorithm
- router communicate with each other
- and creates a forwarding table

![](https://i.imgur.com/c5nfT7X.png)

## SDN software defined networking
a remote controller computes, and install fowarding tables in routers

![](https://i.imgur.com/H73GPsc.png)

# routing algorithms

# routing in the internet

# ICMP