The Art of Network Architecture: Business-Driven Design

Chapter 12. Building the Second Floor

Virtualization is building vertically with overlay topologies, rather than horizontally with a larger physical topology—this process can be described as building the “second floor” of a network. Just as a construction crew has specific tools and techniques they use to build the second floor of a building, the network architect has tools used to build the network’s second floor.

To understand these tools and techniques, we need to first define tunneling—something that’s harder to do than it might seem. Although there are virtualization techniques that do not rely on tunneling (such as 802.1Q in the Ethernet world), they still rely on multiple overlaying control planes, and hence often face the same sorts of ...