Starter

Write down two pros and two cons of using computer networks.

Types of computer networks

Learning Intentions

  • Explain what a network is

  • Be able to explain how networks are connected together

  • Be able to explain the difference between the peer-to-peer model and client-server model

     

Success Criteria

  • I am able to explain what a computer network is
  • I can discuss the advantages and disadvantages of client-server based networks vs peer-to-peer networks

Types of network

  • Wide Area Network or WAN

    • Covers countries and continents

  • Local Area Network or LAN

    • Covers a small area such as a school, home or office

Servers

A server is a special computer designed to carry out one specific job for another computer. There are several types of server including:

  • File servers

  • Print servers

  • Mail servers

  • Application servers

  • Web servers

Servers

  • A file server is is used as a central file storage. Users are given specific rights (such as read and write) to certain parts of the file server.
  • A print server is used to share a printer on the network
  • A mail server is used to send and receive emails
  • An application server is one that allows applications to be stored once on a server and then loaded on to the client computer's RAM when it is needed
  • Web servers are connected to the Internet and are used to host web and deliver webpages and files that can be accessed from any computer using a web browser.

Client-server network

  • At the centre of a client-server network is a server that is responsible for allocation of resources

  • The client(s) access resources that the server manages and provides users with access to these resources

Client-server network

  • At the centre of a client-server network is a server that is responsible for allocation of resources

  • The client(s) access resources that the server manages and provides users with access to these resources

Client server vs Peer-To-Peer

Client-server advantages:

  • One central file storage means that it is easier to set access rights to files and to back up the files

  • The same files can be accessed from any computer

Client-server disadvantages:

  • Cost – initial set up is expensive

  • Requires someone to manage the server

Peer-To-Peer vs Client-server

Peer-to-peer advantages:

  • Easy setup: most computers are ready to go out of the box

  • Cheap to setup: you need a few computers and cables and you’re good to go

Peer-to-peer disadvantages:

  • Backups are difficult because files are stored on different computers across the network

  • Security of files is not easy to enforce since it is not in a single central location

Networking devices

There are several types of networking devices, each with its own specific purpose within a network topology. The following devices are used to make up a network:

  • Hub
  • Switch
  • Router

 

A hub

  • A hub is a very basic device that allows multiple users to share one connection. The bandwidth of the connection is split between all ports on the hub. So if the network connection operated at 100Mbps and it had four ports, each port on the hub would have 25Mbps.
  • Hubs are very simple to build but also very slow compared with the more advanced switch.

Switch

  • A switch is a more advanced version of a hub whereby the ports are given the full bandwidth of the network connection they are connected to.
  • They achieve this by using a technique known as polling where they move through each port on the switch very quickly and gives the full bandwidth of the port for a short period then moves on.

Routers

  • Routers are used to connect multiple networks together. For example, your home router will connect your home network (often built-in to the router too) to the Internet.
  • Routers are very common now, but back in the early 2000s most people had one connection to the Internet through a modem.

Complete the questions in the Networking worksheet 2.
Continue your PowerPoint on networks. Add into it about client-server networks and peer-to-peer networks as well as hubs, switches and routers.

Task

Plenary

  1. Colour in your worksheet based on the descriptions of each key word using the colours below

JB
3 Computer Networks : 2.1 Network types
© J Balfour
Tools