Top 10 principles for the NETWORK LAYER

I'm participating in a Network class. In the chapter about Network Layer, there are 10 essential principles in designing this layer. I think it's useful for other things as well.

1. Make sure it works.
2. Keep it simple.
3. Make clear choices.
4. Exploit modularity.
5. Expect heterogeneous.
6. Avoid static options and parameters.
7. Look for a good design; it need not be perfect.
8. Be strict when sending and tolerant when receiving.
9. Think about scalability.
10. Consider performance and cost.

In addition, there is another principle for technology named KISS. It means "Keep It Simple and Stupid".