ABSTRACT
One of the most challenging aspects of understanding telecommunications and network security is the
overwhelming number of resources that are required to maintain it. Making telecommunications and
networking “work” involves millions of miles of cabling, thousands of communications devices, and an
uncounted number of people all working together to deliver information among devices. Whether the
information is a word-processing document, an e-mail message, an Internet phone call, or an ATM
transaction, it starts from a device and traverses media that are largely unknown to most people. The
focus of this chapter is on those media that carry the information. From the thousands of miles of optical
cable that run deep beneath the oceans to connect continents, to the inexpensive “patch” cables that are
sold in hardware stores, to home users, each has an important role to play and each has an implication in
securing a network environment from one end to the other.
