Introduction to Computer Networking – SS3 Data Processing Lesson Note (First Term)

Computer networking is the practice of linking two or more computing devices together to share data, using computer hardware and software.

Behavioural objectives

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

1. Define networking, network design, network protocols and network topology.
2. Name the two basic network design forms and state how they differ.
3. Name and describe the common network topologies.
4. Give examples of network protocols and state what they do.
5. Explain the meaning of Internet, intranet and extranet.

What is computer networking?

Networking is the practice of linking two or more computing devices together to share data.

• Hardware: the physical parts, such as computers, cables, switches, routers and network cards.
• Software: the programs that control the network, such as the operating system and network protocols.

Why do we use computer networks?

• Sharing data: users send and receive files and messages.
• Sharing resources: many computers can use one printer or one storage device.
• Communication: users send email and hold online meetings.
• Internet access: one connection can serve many devices, as in a school or home network.

What is network design?

Network design is the way a network is organised, and the two basic forms are client/server and peer-to-peer.

What is a client/server network?

• Meaning: a network with centralised server computers that store email, Web pages, files and applications.
• Client: a computer that asks the server for a service or file.
• Example: a school network where all students log in to one central server.

What is a peer-to-peer network?

• Meaning: a network in which every computer has equal status and can share files directly with the others.
• Example: a small home or office network with no central server.

What is the difference between client/server and peer-to-peer?

What is network topology?

A network topology is the layout or structure of a network from the point of view of data flow.

There are five common topologies: bus, star, ring, mesh and tree.

What are the types of network topology?

• Bus: all devices connect to one main cable.
• Star: every device connects to a central hub or switch.
• Ring: each device connects to two neighbours, forming a closed loop.
• Mesh: each device connects to many or all of the other devices.
• Tree: several star networks are joined to a main cable, in layers.

What are the strengths and weaknesses of each topology?

What are network protocols?

Network protocols are the communication languages, or sets of rules, that computer devices use to exchange data.

• Networks can also be classified by the set of protocols they support.
• Networks often implement multiple protocols, with each supporting specific applications.

What are examples of network protocols?

• TCP/IP: the most common protocol on the Internet and in home networks.
• HTTP: transfers Web pages between a server and a browser.
• FTP: transfers files between computers.
• SMTP: sends email.

What are the Internet, an intranet and an extranet?

The Internet, an intranet and an extranet are three types of network that differ in who can use them and how they connect.

What is the Internet?

The Internet is the global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link devices worldwide.

• It is a network of networks.
• It consists of private, public, academic, business and government networks of local to global scope.
• These networks are linked by a broad array of electronic, wireless and optical networking technologies.

The Internet carries an extensive range of information resources and services:

• World Wide Web (WWW): interlinked hypertext documents and applications.
• Electronic mail: messages sent between users.
• Telephony: voice calls over the network.
• Peer-to-peer networks: used for file sharing.

What is an intranet?

An intranet is a private network that is contained within an enterprise.

• It may consist of many interlinked local area networks.
• It may also use leased lines in the wide area network.
• It typically includes connections through one or more gateway computers to the outside Internet.

The main purposes of an intranet are:

• To share company information and computing resources among employees.
• To facilitate working in groups.
• To support teleconferences.

What is an extranet?

An extranet is a private network that uses Internet technology and the public telecommunication system to securely share part of a business’s information or operations with outsiders.

• Who can use it: suppliers, vendors, partners, customers or other businesses.
• Link to the intranet: it can be viewed as part of a company’s intranet that is extended to users outside the company.
• “State of mind”: it has also been described this way, as the Internet is seen as a way to do business with other companies and to sell products to customers.

What is the difference between the Internet, an intranet and an extranet?

Evaluation

1. Define networking, network design, network protocols and network topology.
2. State two differences between a client/server network and a peer-to-peer network.
3. Name three network topologies and describe one of them.
4. Give two examples of network protocols and state what each does.
5. Explain the meaning of Internet, intranet and extranet.

Assignment

State the two basic network design forms, then write short notes on an intranet and an extranet.

Teaching guide

Instructional techniques

• Identification
• Explanation
• Questions and answers
• Demonstration
• Videos from source

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

Closing the lesson

• The teacher commends the students positively.