Navigating Network Complexity: Next-generation Routing with SDN, Service Virtualization, and Service Chaining

Chapter 1. Defining Complexity

Computer networks are complex.

But what does “computer networks are complex” mean? Can you put a network on a scale and have the needle point to “complex”? Is there a mathematical model into which you can plug the configurations and topology of a set of network devices that will, in turn, produce a “complexity index”? How do the concepts of scale, resilience, brittleness, and elegance, relate to complexity? The answers to these questions are—unfortunately—complex. In fact, the most difficult issue involved in answering these questions is deciding where to begin.

The best place to begin is at the beginning—in this case a few definitions of complexity, from “everything I don’t understand,” to “that which involves ...