Router internals

Routers have queues
- Typically one queue per physical poort
Any computer could be a router
- Your personal computer is routing and can act as a router
- But the message bus becomes a bottleneck
High-speed routing involves a crossbar switch
Crossbar has a certain number of parallel channels that can be switched from one connection pair to another
- You have a central processor that regulates the switching
- Expensive: need switching points
Think of a bus as a rotary and a crossbar like a cloverleaf
Port queues can be prioritized/scheduled
- There are lots of algorithms for this, achieving different goals
- This is what net neutrality is about

IP control plane

This was an algorithm-focused section. While interesting, it’s more detailed than is needed for my day-to-day work.