At this point, the class is transitioning a bit, away from low-level protocol issues, to higher-level, large-scale applications. Today, we took advantage of the transition to wedge ifew pieces of real-world deal. For reference, I've linked to a few real-world documents that cover the topics well:

• 3-tier Enterprise/Campus architecture: Cisco Tutorial
• Hot-Aisle/Cold-Aisle Data Centers: APC Data Center Cooling Tutorial