Networking devices and their functions

The network is built of many components, including the networking devices such as routers and switches interconnected by links. These links may be local, connecting two devices side by side like a patch cord connecting two switches, or a Wide Area Network (WAN) link that connects two routers that are in different locations. This section introduces some of the common devices that are used to build the networks and the broad functions of these devices.

Switches

A switch is a device that operates at layer 2 of the OSI stack, and is the most common device that you would find in the network.

Many layer 2 technologies came into existence at different times, to meet user requirements. Some of these layer 2 technologies are X.25, Frame Relay, ATM, and Ethernet. There are switches available for each of these technologies.

Out of the multiple layer 2 competing technologies, Ethernet became the de facto standard at layer 2 of the OSI model, primarily driven by its...