Characterizing Computer Networks

What is a Network

In this book, we use the following simple, but complete, definition of computer networks:
A computer network is a set of computers that are connected and able to exchange messages.

It is important to note that this definition excludes a large time-sharing system with a collection of terminals attached, a type of systems that is sometimes called a network. In our descriptions and discussions of networks, we assume that each station on the network is a computer that can be used independently of the network; the network is an extension of the computing environment offered by that computer. Our networks may also include some devices, such as printers, used only through the network. Because these devices cannot operate in a stand-alone mode, we will not consider such devices to be stations or nodes on the network, but as a separate category of peripheral devices, accessed through the network.

Return to the chapter overview.

The Concept of Layering

The OSI Reference Model

The ARPA Suite of Protocols

ISODE

SNA

Local Area Networks

Wide Area Networks

Metropolitan Area Networks