1.3 Computer networks, connections and protocols

Give 2 advantages of a wired network.

Fast connection/speed / high bandwidth / consistent bandwidth; Secure / unlikely to have unauthorized access/be hacked / data transmissions are likely to be safe

Give 2 disadvantages of a wired network.

Needs cables / limited mobility; Installation is expensive / difficult to install in large areas

Give 2 advantages of a wireless network.

Device can be used anywhere in range / mobility; Easier to add devices / scalable

Give 2 disadvantages of a wireless network.

Prone to interference; Less secure / higher risk of hacking or interception

What is a client-server network?

Network where clients request services and a central server provides resources and manages the network

Give 2 advantages of client-server networks.

Centralised backups/security/updates; Easy to manage and scalable

Give 2 disadvantages of client-server networks.

Single point of failure; Expensive to set up and maintain

What is a peer-to-peer network?

Network where all devices have equal status and share resources directly without a central server

Give 2 advantages of peer-to-peer networks.

No central server cost; No single point of failure

Give 2 disadvantages of peer-to-peer networks.

Weak security / decentralised security; Dependent on other devices being online

What is a star topology?

All devices connect to a central switch/hub that controls data flow

Give 2 advantages of star topology.

Easy to add devices; One device failure does not affect the whole network

Give 2 disadvantages of star topology.

Central switch failure stops network; Higher cost due to central device

What is a mesh topology?

Devices are connected to multiple or all other devices with multiple data paths

Give 2 advantages of mesh topology.

No single point of failure; Very reliable with multiple routes

Give 2 disadvantages of mesh topology.

Expensive due to many connections; Difficult to install and manage

What is a LAN?

Network covering a small geographical area owned by the user

What is a WAN?

Network covering a large geographical area connecting multiple LANs

What does a wireless access point do?

Allows wireless devices to connect to a wired network using radio signals

What does a router do?

Sends data packets between networks and finds best route to destination

What does a switch do?

Connects devices in a network and uses MAC addresses to send data to correct device

What does a NIC do?

Provides connection to a network and contains the device’s MAC address

What is transmission media?

The physical or wireless path used to transmit data (cables or radio waves)

What is a MAC address?

Unique hardware address used to identify a device on a local network

What is the format of a MAC address?

48 bits; 6 groups of hexadecimal numbers

What is an IPv4 address?

4 groups of numbers from 0–255 separated by dots

What is an IPv6 address?

8 groups of hexadecimal numbers separated by colons

What is an IP address used for?

Identifies a device on a network and allows data routing across networks

What is a protocol?

A set of rules that allows devices to communicate

What is HTTP used for?

Accessing websites via a web browser

What is HTTPS used for?

Secure access to websites using encryption

What is FTP used for?

Transferring files between client and server

What is SMTP used for?

Sending emails from a client to a server

What is IMAP used for?

Retrieving emails while keeping them synced across devices

What is packet switching?

Data is split into packets which are sent independently and reassembled at destination

What is inside a packet header?

Destination address and packet number

What happens if packets are lost?

They are resent and reassembled at the destination

What is DNS?

Converts domain names into IP addresses

What are the advantages of cloud storage?

Access from anywhere; Automatic backup and reduced need for physical storage

What are the disadvantages of cloud storage?

Requires internet access; Security depends on provider and risk of interception

What does a web client do?

Sends HTTP/HTTPS requests using a browser

What does a web server do?

Stores websites and sends HTTP/HTTPS responses to clients