Chapter 2
Layer 1: The Physical Layer
Introduction
The physical layer (layer 1) sits at the bottom of the Open Systems Interconnect (OSI) model, and is designed to transmit bit streams using electric signals, lights, or radio transmissions. For this chapter, the definition of the physical layer is expanded to include all physical things. True security means building defense-in-depth, which is used in this chapter to expand the OSI concept on a much broader scale. We begin by looking at some of the methods used to defend the physical environment, including common concepts ...
Get Hack the Stack now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
