networks and topologies

A network is two or more devices connected together to share resources.

A LAN is a network within a small geographical area, usually under 1 mile.

A WAN is a network spanning a large geographical area, made up of connected LANs and uses external hardware such as satellites and telephone lines.

Users can share resources like printers and internet connection and users can access files and communicate easily from any computer on the network.

There is an increased security risk to data from malware or hackers.

True. LANs use hardware owned by the company/organisation, not shared public infrastructure.

False. A WAN connects networks over a large geographical area spanning miles.

WANs use routers, telephone lines, fiber optic cables, and satellites to connect LANs.

The 5 factors that affect network performance are:

Bandwidth is the amount of data that can be transmitted per second, measured in bits per second.

Latency is the delay between data being sent and received.

The error rate measures how many data packets do not reach their destination.

Transmission media refers to the cable type used for wired network connections.

False. More users reduce the available bandwidth per user, potentially slowing the network.

Fibre optic cables have the highest bandwidth compared to copper cabling.

An increased error rate occurs with less reliable connections like poor wireless signals.

If the maximum bandwidth is used, devices cannot transmit data until bandwidth frees up.

Using higher bandwidth or more reliable transmission media can decrease latency.

The client-server model has dedicated server machines that provide services to client machines.

A server manages resources like internet access, printing, email, backups, and security.

In a peer-to-peer model, all computers are equal peers with no dedicated servers. Each computer is responsible for managing its backups, security and connections.

Centralised backups, updates, and security makes managing the network easier.

Servers are expensive to purchase and maintain, and require specialist IT staff.

Peer-to-peer networks are very easy to maintain and cheap to set up.

Each user must manage their own backups, updates, and security on their device.

False. Most homes use a peer-to-peer model without dedicated server machines.

True. ** If the central server fails, all client machines lose access** to network services.

A router routes data between different networks like a LAN and the internet (WAN).

A WAP allows wireless devices to connect to a wired LAN.

A switch connects multiple wired devices to a LAN and routes data between them.

A NIC allows a computer to send and receive data on the network.

Transmission media refers to the cables used for wired network connections.

The three main types of cable are:

Unshielded twisted pair (UTP) cable has the lowest bandwidth.

Fibre optic cables are unaffected by electrical noise.

True. Switches are active devices that inspect network data to route it efficiently.

The Internet is a massive collection of interconnected networks spanning the world.

The Internet provides connectivity, while the World Wide Web is the collection of web pages accessed via browsers.

An ISP provides internet access and connects the user's network to the Internet.

DNS stands for Domain Name System.

DNS translates human-readable domain names (web address) to IP addresses for connecting to web servers.

True. Web servers are used to serve web pages to clients.

Hosting refers to storing websites and serving them from dedicated web servers.

Cloud computing uses remote servers on the internet to store data and run applications.

True. Cloud data can be accessed anytime from any internet-connected device which has the login credentials.

True. Expanding the capacity is easy, yet expensive when done on mass.

A network topology is the physical structure of the network. It defines how the network hardware will be arranged to create the network.

True. All devices connect to a central switch in a star network topology.

True. If any single cable stops working in a star topology, the rest of the network will continue to work.

The central switch is a single point of failure. This means that if the switch stops working, all of the devices connected to it will not be able to connect to the network or any of its facilities and resources.

A mesh topology allows all computers to be connected to all other computers. This is known as a full mesh network topology.

True. Devices like smart thermostats, security cameras, and smart light bulbs often form a mesh network to communicate with each other and a central hub.

False. If any single cable stops working in a mesh topology, the rest of the network will continue to work as the data can find a different route to get to its destination.

A disadvantage of a mesh topology is the increased complexity and cost of the setup and maintenance due to the numerous interconnections between devices.

A partial mesh topology is where each device is not connected to every other device directly, requiring less cables and hardware than a full mesh.

A topology where some devices are connected to all others, while other devices are connected only to those devices with which they exchange the most data.