58.2. Networking Protocols and Layers

A networking protocol is a set of rules defining how information is to be transmitted across a network. Networking protocols are generally organized as a series of layers, with each layer building on the layer below it to add features that are made available to higher layers.

The TCP/IP protocol suite is a layered networking protocol (Figure 58-2). It includes the Internet Protocol (IP) and various protocols layered above it. (The code that implements these various layers is commonly referred to as a protocol stack.) The name TCP/IP derives from the fact that the Transmission Control Protocol (TCP) is the most heavily used transport-layer protocol.