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Computer-Science-A-level-Ocr

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  12. structuring-your-responses
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LAN & WAN

What is a local area network (LAN)?

  • LANs are networks that are contained within a  small geographical location 

  • Typically, all the hardware used to make a LAN is owned by a single entity

    • This makes them more secure than WANs, which have connections owned by third-party companies

  • A LAN is a network that is built using hubs and/or switches that connect several devices

  • It is common for one hub or switch to be connected to a router, which will allow the LAN to connect to other networks, such as the Internet

  • A LAN can offer many advantages, such as:

    • Centralised management – A LAN allows centralised management of updates, backups and software installations

    • Security – A LAN can secure its devices with the use of firewalls, antivirus software and other security features to prevent unauthorised access

    • File Sharing and collaboration – A LAN allows users on the network to share resources such as printers and other peripherals. Users of the network can also collaborate and share files and folders

  • Disadvantages of a LAN include:

    • If hardware fails, the network may not function properly or even at all

    • Networks are more prone to attacks than standalone computers

    • Access to data and peripherals can be slow depending on network traffic when compared to locally stored data and locally connected peripherals

    • Maintenance – LAN networks require maintenance to ensure that software is up to date. Upgrades and backups can be costly

What is a wide area network (WAN)?

  • A wide area network (WAN) connects multiple local area networks (LANs) over a large geographical area

  • A WAN allows users in different locations to share data and resources as if they were on the same network

  • WANs usually use third-party connections such as leased lines, fibre, or satellite links

  • These connections are provided by ISPs or telecommunications companies rather than owned by a single organisation

  • For example, a company may connect its LANs in London and Manchester to create a WAN

Advantages of a WAN

  • Enables communication and data sharing between offices or sites in different locations

  • Allows access to central servers and shared databases from anywhere with a connection

Disadvantages of a WAN

  • Typically slower than LANs due to greater transmission distances

  • More expensive to set up and maintain because of leased lines or ISP costs

  • More vulnerable to security risks as data travels across public networks

Worked Example

The internet can be considered an example of a WAN.

Describe what is meant by the term ‘WAN’.

2 marks

How to answer this question:

  • For 2 marks, you need to make 2 points about what a WAN is

  • Since the question uses WAN as an acronym, it is a good idea to show you know what WAN stands for

Answer:

Example answer that would get full marks:

A WAN (short for Wide Area Network) is a network spread over a large geographical area such as a country.

Worked Example

A coffee company has coffee shops located across the country. Each shop has its own Local Area Network (LAN)

The company wants to connect the shops in a Wide Area Network (WAN).

Describe two characteristics of a LAN.

2 marks

How to answer this question:

  • You need to make 2 points about how a LAN is different from a WAN:

    • LANs cover a small geographical area

    • The hardware that makes up the LAN is typically owned by one company

    • For this reason, a LAN is considered to be more secure than a WAN

Answer:

Example answer that would get full marks:

LANs are considered more secure than WANs since the LAN’s connections are owned by the organisation that owns the LAN.

Responses

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