DEVICE CLASSIFICATION

A device that is connected to a network can be classified as a user or host device or as a networking device.

A user or host device is a device that can exist without a network. For example, a computer or a printer is an example of such a device.

A networking device is a device that has the primary function of providing transportation services for data to be transferred between host devices. A router is an example of a networking device.

MAC ADDRESSES

All devices that connect to a network have a unique MAC address. This unique address is used by switches to send information to its destination. A MAC address, sometimes called a physical address as it cannot be changed, is a 48-bit or 12 hex digit number that looks like this:

08-00-27-EC-10-61 (on Windows)

08:00:27:EC:10:61 (on Mac/Linux/ChromeOS)

TYPES OF DEVICES

The following video summarizes common networking devices such as hubs, bridges, switches and routers.

Link: https://www.youtube.com/watch?v=eMamgWllRFY

TERMINOLOGY

A collision domain is a part of a network where devices share a medium (such as a cable) in such a way that simultaneous transmission of data leads to a collision. When a collision occurs, the data has to be resent.

When referring to layer, the video is referring to the OSI model which separates different responsibilities into different layers. We will learn more about this later.

A half-duplex device can either receive or send data at a specific time. A full-duplex device can receive and send data at the same time.

WORK

1. List the four networking devices described in the video.

2. Associate each description below with a networking device.

a) This networking tool connects your computer or network to other networks such as the internet. It uses IP addressing.

b) This networking tool connects many devices together. When it receives data from one of the devices, it sends that data to all other devices.

c) This networking tool segments a network into two parts. When it receives data, it determines if it should ignore it or send it to the other side.

d) This networking tool connects many devices together. It keeps tracks of MAC addresses to know where to send the data.

3. Complete the following table:

Networking Device	Layer	Collision Domains	Replaced by
Hub
Bridge
Switch
Router

4. Most home networks only have a router. Why don’t they have a switch as well?

5. We have discussed half-duplex and full-duplex. Take a minute to research what the term simplex means. Now associate each of the following with either simplex, half-duplex or full-duplex.

a) Keyboard

b) Telephone

c) TV

d) Walky-talky