Overview

Everyone seems to loosely use the term network to describe the unseen hardware and software that almost seamlessly and sometimes almost magically transports our data and voice and soon our videos. The word network is even shortened to net as common vernacular for the Internet and can be used as either a verb or noun. Yet it is difficult to define exactly what the net is. To most users, it is almost ethereal. Its hardware is typically invisible to the user (ignoring the proliferation of those ugly cell towers) and requires little or no control by the user, and users barely think of the myriad of fibers, lasers, and switches that it takes to download that swimsuit photo or talk to Mom.

A telecommunications network can be loosely defined as all of the hardware and software required for transmitting, routing, and delivering information, including all of the lines and interconnects. However, sometimes the hardware and software used to generate, collect, or display the information is not included in the concept of the "net." As such, networks owned by various companies need to seamlessly interact and connect to other networks.

Network architecture is an eclectic mix of art, science, and gut feelings. In addition, a vast amount of time is spent (usually by professional organizations) to create standards that enable the net. There is always a desire for the ability to engineer a network and achieve the maximum performance at minimal cost. However, even this simplistic metric...