Networks (Cambridge (CIE) IGCSE ICT): Flashcards

A bridge is a device used to connect two local area networks together to create one larger network.

Unlike a switch or hub, a bridge only connects local area networks together.

False.

MAC addresses are static and never change. It is the IP address that is dynamic and changes when a device moves to a different network.

A MAC address is made up of 12 hexadecimal digits, usually grouped in pairs.

A wireless network is a network where connections are made using radio waves to transmit data through the air.

The two most common types of wireless connection are Wi-Fi and Bluetooth.

A device communicates with a hotspot or a wireless access point (WAP), which can be a standalone device or built into a router or switch.

Wi-Fi is preferred when high speed data transfer is required, when long range communication is required, and when many devices need to be connected at the same time.

Wi-Fi offers portability, since location is only limited by range; lower cost to set up and add new devices; and compatibility, as most devices have a built-in Wi-Fi adapter.

Wi-Fi has slower data transfer than Ethernet, is less secure than Ethernet, and its range relies on signal strength to the WAP, so signals can be obstructed.

Bluetooth is typically used for a direct connection between two devices, such as headphones, controllers, keyboards and mice.

They exchange a cryptographic key, which is used to generate a secret shared key. This encrypts the data between them and creates a Wireless Personal Area Network (WPAN).

FHSS is where connected devices continuously change their transmitting frequency between 79 different channels to avoid interference and improve the reliability of the connection.

False.

Bluetooth has a maximum range of about 30 metres, whereas Wi-Fi reaches about 100 metres, depending on obstructions.

Bluetooth supports a maximum of 7 connections, whereas Wi-Fi supports a maximum of 30.

Bluetooth has very low power consumption, which makes it ideal for personal devices.

Cloud storage is long-term secondary storage of data that resides in a remote location, accessible only via a wide area network such as the internet.

Cloud data is stored on remote servers, typically using magnetic storage (HDD), but increasingly using solid state (SSD).

The three types of cloud storage are public cloud, private cloud and hybrid cloud.

In a public cloud, the customer and the cloud storage provider are different companies.

In a private cloud, the customer and the cloud storage provider are a single organisation.

A hybrid cloud combines public and private cloud options, allowing sensitive data to remain private while providing public cloud services for less sensitive information.

False.

A stable internet connection is required to use cloud storage.

Data can be accessed from anywhere and on any device; it can be shared quickly with anyone holding the relevant permissions; capacity can be increased or decreased as needed; providers use multiple servers to back up data; providers offer advanced security features; and there is no need to hire specialist staff.

A stable internet connection is required; data may be vulnerable to security breaches; the user is dependent on the provider for availability and reliability; data may be lost if the company ceases to exist; and the service can become expensive over time.

Cloud storage involves storing data on remote servers accessed via the internet, while local storage refers to storing data on physical devices such as hard drives or flash drives.

Cloud providers protect user data with security features such as data encryption and multi-factor authentication.

Providers often use multiple servers to store and back up data, reducing the risk of data loss due to hardware failure.

The internet is a global network of networks: multiple local area networks connected together to form a large wide area network.

False.

The web is a collection of websites and web pages accessed using the internet. The internet is the underlying network that provides the connectivity.

Once authenticated, an extranet user has managed access to network resources and information.

The internet is the most well-known wide area network (WAN).

Web pages are accessed using a web browser, which communicates with web servers to retrieve and display the content.

An intranet is a private network designed to work much like the internet, but which operates only within a local area network.

An intranet can be accessed only by authorised users, exclusively the organisation's employees. It sits behind a firewall to ensure security.

An intranet offers better bandwidth, keeps data within the organisation, carries less chance of hacking and attacks, and lets administrators manage access to external sites and links.

An extranet is an extension to an intranet that allows authorised access from outside the local area network.

An extranet is useful for providing access to customers, clients and key stakeholders.

They are all web based technologies, they all allow users to access information remotely, they all use client server architecture, they all use security measures such as authentication and encryption, and they all facilitate information and resource sharing.

An intranet is accessible to employees of the organisation and not to members of the public.

A network is two or more devices connected together with the purpose of sharing resources.

A LAN is a network with a small geographical area, under one mile, in which all of the hardware is owned by the company, organisation or household using it.

A WAN is a network with a large geographical area, over one mile, made up of a collection of LANs joined together.

A WLAN is a local area network where devices connect to the network wirelessly instead of using cables.

A WLAN needs wireless access points (WAPs) or hotspots connected to the network so that users can connect using Wi-Fi.

False.

In a LAN all the hardware is owned by the organisation using it. In a WAN the hardware is not all owned by them, for example telephone lines owned by telecommunication companies.

The computers on a wide area network are connected via routers.

A LAN uses unshielded twisted pair (UTP) cable, fibre optic cable or wireless connections (Wi-Fi).

A LAN allows centralised management of updates, backups and software installations; lets devices be secured with firewalls and antivirus software; allows users to share resources such as printers; and allows users to collaborate and share files and folders.

If hardware fails the network may not function properly; networks are more prone to attacks than standalone computers; access can be slow depending on network traffic; and they require costly maintenance.

A WLAN has limited coverage, which walls and other structures can worsen; bandwidth speeds can suffer in high traffic areas; there can be interference from other devices; and it is vulnerable to security threats because wireless signals can be intercepted.

A WAN uses fibre optic cable, telephone lines and satellite to connect the LANs together.