3_5_1 Understand Network Architecture

You should be able to:

  • Define what a computer network is.
  • Discuss the benefits and risks of computer networks.
  • Describe the main types of computer network including:

•• Personal Area Network (PAN)

•• Local Area Network (LAN)

•• Wide Area Network (WAN)

  • Understand that networks can be wired or wireless.
  • Discuss the benefits and risks of wireless networks as opposed to wired networks.
  • Explain the following common network topologies:

•• star

•• bus

REVISE:

What is a network?

A computer network is a number of computers linked together to allow them to share resources. Networked computers can share hardware, software and data.

Most computer networks have at least one server. A server is a powerful computer that provides one or more services to a network and its users. For example, file storage and email.

Advantages and Disadvantages

Advantages:

  • Data can be shared quickly and easily
  • Resources can be shared. For example, a printer can be shared amongst a whole classroom
  • Data can be backed up in a central location (server)
  • The network can be updated via the server instead of updating each individual machine
  • Files are stored centrally so that a user can access their files from any location connected to the network

Disadvantages:

  • Viruses can be spread quickly due to the connectivity of the computers
  • If the server breaks then all of the computers on the network will stop working
  • It can be expensive to set up
  • The set-up and maintenance requires specialist expertise

The Three Main Types of Network

PAN (Personal Area Network)

This is a network that is connected to one individual. Usually as close as 10 meters away from the person. For example, if you are wearing a smart watch and you also have a smart phone then you will have your own PAN because the smart watch will be talking to the smart phone and sharing data.

LAN (Local Area Network)

Covers a small area such as one site or building, eg a school or a college.

WAN (Wide Area Network)

Covers a large geographical area. Most WANs are made from several LANs connected together. An example of a WAN is The Internet.

Wired and Wireless

Networks can be:

  • Wired (connected only through hard wiring)
  • Wireless (connected only through wireless technology)
  • Mixed (a mixture of both wired and wireless)

Wired vs Wireless

Wired:

Negatives

  • They are expensive to set up
  • It takes more time to set up
  • Its harder to expand the network
  • The workstations must be next to a network connection to work

Positives

  • The connection is more stable
  • A wired network is more secure

Wireless:

Negatives

  • They are less secure
  • File sharing can be slower without a stable connection
  • Interference can occur meaning temporary loss of connection

Positives

  • They are cheaper to set up than a wired connection
  • It is easier to expand the network
  • A wireless network doesn't limit the number of users through physical network ports
  • It allows for mobility, workstations just need to be in range of a wireless connection

Network Topologies

You need to know about Star and Bus

Information on these topologies can be found here: http://www.bbc.co.uk/education/guides/zh4whyc/revision/3

TEST:

  1. Download and print the test paper here: https://drive.google.com/open?id=0B5fLtQ0Xgr2PVVQxdzBHS2h5Rzg
  2. Try the mock test yourself.
  3. Use the 3.5.1 Walking Talking Mock below to guide you through answering the questions.

SOURCE RECOGNITION - PLEASE NOTE: The examination examples used in these walking talking mocks are samples from AQA from their non-confidential section of the public site. They also contain questions designed by TeachIT for AQA as part of the publicly available lesson materials.