1.2.2 Data Networking Hardware and Connections

In Chapters 4 and 5, you will learn about infrastructure and client hardware in detail. At this point, you should gain a fundamental understanding of the hardware so that you can fully understand the topics in Chapters 2 and 3. This section addresses switches and routers as well as remote network connections.

Switches and Routers

Switches and routers are the building blocks of modern networks. The switches provide access to the network, and the routers build the network links between groups of switches. The following sections briefly explain each of these two important devices.

Switches

Telecommunications networks can implement two primary kinds of switching: circuit switching and packet switching. Circuit switching is used to reserve a route or path between the two endpoints that need to communicate. Because a circuit is reserved, the entire communication is sent in sequence and there is no rebuilding of the data at the receiver, as it is certain to arrive in order. Of course, this reservation means the bandwidth cannot be utilized by any other devices that may need it and can make circuit switching rather costly in today’s packet-switched world. The benefit of circuit switching is that the connection is always there and the bandwidth is guaranteed as long as the connection exists.