DWDM, Switching, Routing: Where and why?

Multiple technologies are capable of moving data quickly and efficiently across a network. When faced with a decision between Apples, Oranges, and Bananas - Which one is right for you?
00:34 Cost Considerations for DWDM, Switching & Routing
03:45 Why DWDM?
5:33 Optical Layer Scalability
17:21 Layer 2 Switching - Service Protection
20:43 Layer 2 Switching - Traffic Engineering
26:03 Layer 3 Routing
32:46 Layer 3 Routing - EVPN