Quiz 11

Question 1

Data plane vs control plane

Answer 1

Data plane - about the local, per-router, per-IP-device actions
- primarily forwarding/moving datagrams
- how a packet is moved from input port to correct output port
- data plane - high speed, implemented in hardware

Control plane - about the network-wide, end-to-end view
- getting packets from one edge of the network to the other
- determines the route of a datagram among routers from source host to destination host
- slower, implemented in software

Question 2

list of router parts

Answer 2

• input & output ports
• high-speed switching fabric
• routing processor

Question 3

routing processor definition

Answer 3

• usually just a CPU
• performs control plane functions
• controls switch fabric
• installs forwarding tables at the input ports

Question 4

high-speed switching fabric definition

Answer 4

• heart of the router
• place through which all packets must pass

Question 5

input port functions

Answer 5

1. line termination (bit-level reception)
2. data link layer (receive)

of ports in a router varies from ~ 1/2 dozen in home router to hundreds in a backbone router

Question 6

Routing vs forwarding

Answer 6

Routing - moving a packet across the network

Forwarding - moving a packet from the input to output port