Types of Network Devices – SS3 Data Processing Lesson Note (First Term)

Network devices are hardware components used to connect computers and other electronic devices so that they can share files and resources.

Behavioural objectives

By the end of the lesson, students should be able to:

1. Define network devices.
2. List nine types of network devices.
3. Describe the function of each network device.
4. Differentiate between a hub and a switch.
5. State the benefits of networking.

Instructional techniques

• Identification: students identify each device from pictures.
• Explanation: the teacher explains the function of each device.
• Questions and answers: students answer oral questions on each device.
• Demonstration: the teacher shows real devices where available.
• Videos from source: short videos on how the devices work.

Instructional materials

• Videos
• Loudspeaker
• Pictures
• Data Processing for Senior Secondary Education by Hiit Plc
• WAPB Computer Studies for Senior Secondary I by Adekunle et al
• Online materials

What are network devices?

Network devices are components used to connect computers or other electronic devices so that they can share files or resources.

• Network: two or more computers or devices linked together to share data and resources.
• Resources shared: files, printers, scanners, fax machines and internet access.

What are the types of network devices?

There are nine common network devices: hub, switch, modem, router, network interface card, repeater, bridge, gateway and access point.

What is a hub?

A hub is a device that joins multiple computers or other network devices to form a single network.

• Connection point: it is a common connection point for devices in a network.
• No intelligence: it does not read the data passing through it.
• Source and destination: it is not aware of where the data came from or where it is going.

What is a switch?

A network switch is a small hardware device that joins multiple computers together within a local area network (LAN).

• More intelligence: it generally contains more intelligence than a hub.
• Inspects packets: it checks each data packet as it is received.
• Finds addresses: it determines the source and destination device of each packet.
• Forwards data: it sends each packet only to the correct device.

What is the difference between a hub and a switch?

A hub passes data on without reading it, while a switch reads each packet and sends it to the right device.

What is a modem?

A modem (MOdulator-DEModulator) is an electronic device that allows computers to communicate over telephone lines.

• Modulation: it converts the computer’s digital signals into signals that can travel on the line.
• Demodulation: it converts incoming signals back into digital data the computer can use.

What is a router?

A router is a device that joins multiple wired or wireless networks together.

• Directs data: it decides the path that data packets take between networks.
• Internet access: it is commonly used to share one internet connection among many devices.

What is a network interface card (NIC)?

A network interface card (NIC) is a circuit board or card installed in a computer so that it can be connected to a network.

• Wired or wireless: a NIC can connect a computer by cable or by wireless signal.
• Needed by every computer: a computer must have one before it can join a network.

What is a repeater?

A repeater is a device that extends the length of a signal so that it can travel further on the same network.

• Copies the signal: it copies the signal bit by bit.
• Regenerates it: it sends the signal on again at its original strength.
• Layer: it operates at the physical layer.

What is a bridge?

A bridge is a device that joins any two networks or host segments together.

• Main function: it stores and relays frames among the connected segments.
• MAC address: it transfers frames using the MAC (Media Access Control) address.
• Filtering: it uses MAC addresses to decide which frames cross to the other segment.
• Larger LAN: it links different physical LANs together to form a bigger logical LAN.

What is a gateway?

A gateway is a passage that interlinks two networks together.

• Messenger agent: it takes data from one system, interprets it and transfers it to another system.
• Protocol converter: it is also called a protocol converter.
• Layers: it can operate at various network layers.

What is an access point?

An access point is a device that connects wireless devices to a wired network.

• Wireless to wired: it lets phones, laptops and tablets join a wired network without cables.
• Ports: it has ports that help to expand the size of the network.
• Extra services: some access points also provide firewall capabilities and DHCP service.
• Combined roles: some units can also act as a switch, DHCP server, router and firewall.

What is the summary of network devices and their functions?

What are the benefits of networking?

The benefits of networking are cheaper software licences, easy file sharing, communication, easy backup and shared resources.

• Cheaper licences: site (software) licences are likely to be cheaper than buying several standalone licences.
• File sharing: files can easily be shared between users.
• Communication: network users can communicate by email and instant messenger.
• Easy backup: data is easy to back up because it is stored on the file server.
• Direct sharing: networking offers a quick and easy way to share files directly.
• Shared resources: all computers in the network can share printers, fax machines, modems and scanners.

Evaluation

1. Mention and explain five types of network devices.
2. Discuss four benefits of computer networking.
3. State two differences between a hub and a switch.
4. What does the word MODEM stand for?

Assignment

Draw a table with two columns, “Device” and “Function”, and fill it in for the nine network devices taught.