Page 756 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

sometimes called the Transport layer (the OSI model’s fourth layer).
The TCP/IP model’s internet layer is sometimes called the Network

layer (the OSI model’s third layer). And the TCP/IP model’s Link layer
is sometimes called the Data Link or the Network Access layer (the
OSI model’s second layer).

Since the TCP/IP model layer names and the OSI model

layer names can be used interchangeably, it is important to know
which model is being addressed in various contexts. Unless
informed otherwise, always assume that the OSI model provides
the basis for discussion because it’s the most widely used network
reference model.

TCP/IP Protocol Suite Overview

The most widely used protocol suite is TCP/IP, but it is not just a
single protocol; rather, it is a protocol stack comprising dozens of
individual protocols (see Figure 11.6). TCP/IP is a platform-
independent protocol based on open standards. However, this is both
a benefit and a drawback. TCP/IP can be found in just about every

available operating system, but it consumes a significant amount of
resources and is relatively easy to hack into because it was designed
for ease of use rather than for security.