I’m teaching a course on router internals over at Safari Books Online on the 24th (in 10 days). From the descriptions:
A network device—such as a router, switch, or firewall—is often seen as a single “thing,” an abstract appliance that is purchased, deployed, managed, and removed from service as a single unit. While network devices do connect to other devices, receiving and forwarding packets and participating in a unified control plane, they are not seen as a “system” in themselves.
The course is three hours. I’m in the process of updating the slides … or rather, I need to get to updating the slides in the next couple of days.