UNIT 4: Networks
[4.1.1] 4.1: Networks:
❖ Network = An arrangement of 2 or more computers and other digital devices that are connected together for the
purpose of sharing resources and data.
❖ Almost all organizations, small or large, have a computer network.
❖ All types of computers and IOT devices can be linked together in networks.
❖ Internet of Things [IoT] = A network of physical objects that use sensors, actuators, embedded systems, and
wireless technology, such as Wi-Fi, Bluetooth, and Zigbee, to collect and exchange data, with minimal or no
human interaction.
[4.1.2] LANS and WANs
❖ Networks can be
identified by the area
that they cover:
LAN [Local Area Network]:
❖ All the devices
connected to a LAN can
share data and files.
❖ LAN users can
communicate via chat
or email.
❖ A LAN is typically
privately owned.
❖ Network managers
are sometimes
employed to install,
configure and maintain the LANs.
❖ The manager is responsible for supporting users and implementing backup and security
measures.
WAN [Wide Area Network]:
❖ Transmission media = The cable or wireless media used to transmit data between devices on a network.
❖ The external communication links used to connect separate parts of a WAN are owned by
telecommunication companies.
❖ WANS are useful for any organization with multiple sites as:
➢ Data can be synchronised and shared.
➢ Software applications and patches can be easily deployed.
➢ Eliminates the need for functions.
➢ Employees can easily log in and work collaboratively.
, [4.1.3] IP Addressing
❖ Internet = The world's largest public WAN. It is a global system of interconnected networks, linking
billions of digital devices worldwide. It is a network of networks, some privately owned, some public.
The reach of the internet is global - multiple satellites and fibre-optic cables connect continents and
countries together. These links, along with others within each country, make up the internet backbone.
❖ Local networks connect to the internet via a POP [Point
of Presence], which is provided by an ISP [Internet
Service Provider].
❖ POP [Point of Presence] = Local access point for an
ISP. Network access points interconnect internet
backbones around the world.
❖ The ISP’s network is connected to a high-level network owned by major telecommunication companies such
as BT or Virgin Media, and each has a dedicated internet backbone.
❖ Networks Access Points [NAPs] interconnect the backbones to form a worldwide mesh network.
❖ Routers forward data from one network across the internet from source to destination, and keep each other up
to date about data traffic in their part of the network so that data can be routed away from congested areas.
❖ Protocol: A set of rules or procedures for transmitting data between electronic devices.
❖ Every internet-connected device has an IP [Internet Protocol].
❖ IP: Internet Protocol – The fundamental protocol for communications on the internet. It specifies how
information is packetized, addressed, transferred, routed, and received by networked devices.
❖ Every device is assigned a unique IP address so that it can send and receive data.
❖ There are 2 versions of IP – Ipv4 and Ipv6.
➢ IPv4 dates back to the 1970s and uses 32-bit addresses – enough for 4 billion devices to be uniquely
identified.
➢ But it is no longer enough. IPv6 uses 128-bit addresses, enough for 340 trillion unique IDs.
▪ An IPv6 address consists of eight groups of 4 hexadecimal digits, separated by colons.
❖ Static IP Address: An IP address that is permanently assigned to a specific network device, such as a router or
server, and doesn’t change.
❖ Dynamic IP Address: An IP address that is temporarily
assigned to a device on a network and then returned to an
address pool so that other devices can use it.
❖ Domain Name: A human-friendly form of an IP address.
Domain names, such as www.pearson.com are much easier to
use than their equivalent IP addresses
[4.1.1] 4.1: Networks:
❖ Network = An arrangement of 2 or more computers and other digital devices that are connected together for the
purpose of sharing resources and data.
❖ Almost all organizations, small or large, have a computer network.
❖ All types of computers and IOT devices can be linked together in networks.
❖ Internet of Things [IoT] = A network of physical objects that use sensors, actuators, embedded systems, and
wireless technology, such as Wi-Fi, Bluetooth, and Zigbee, to collect and exchange data, with minimal or no
human interaction.
[4.1.2] LANS and WANs
❖ Networks can be
identified by the area
that they cover:
LAN [Local Area Network]:
❖ All the devices
connected to a LAN can
share data and files.
❖ LAN users can
communicate via chat
or email.
❖ A LAN is typically
privately owned.
❖ Network managers
are sometimes
employed to install,
configure and maintain the LANs.
❖ The manager is responsible for supporting users and implementing backup and security
measures.
WAN [Wide Area Network]:
❖ Transmission media = The cable or wireless media used to transmit data between devices on a network.
❖ The external communication links used to connect separate parts of a WAN are owned by
telecommunication companies.
❖ WANS are useful for any organization with multiple sites as:
➢ Data can be synchronised and shared.
➢ Software applications and patches can be easily deployed.
➢ Eliminates the need for functions.
➢ Employees can easily log in and work collaboratively.
, [4.1.3] IP Addressing
❖ Internet = The world's largest public WAN. It is a global system of interconnected networks, linking
billions of digital devices worldwide. It is a network of networks, some privately owned, some public.
The reach of the internet is global - multiple satellites and fibre-optic cables connect continents and
countries together. These links, along with others within each country, make up the internet backbone.
❖ Local networks connect to the internet via a POP [Point
of Presence], which is provided by an ISP [Internet
Service Provider].
❖ POP [Point of Presence] = Local access point for an
ISP. Network access points interconnect internet
backbones around the world.
❖ The ISP’s network is connected to a high-level network owned by major telecommunication companies such
as BT or Virgin Media, and each has a dedicated internet backbone.
❖ Networks Access Points [NAPs] interconnect the backbones to form a worldwide mesh network.
❖ Routers forward data from one network across the internet from source to destination, and keep each other up
to date about data traffic in their part of the network so that data can be routed away from congested areas.
❖ Protocol: A set of rules or procedures for transmitting data between electronic devices.
❖ Every internet-connected device has an IP [Internet Protocol].
❖ IP: Internet Protocol – The fundamental protocol for communications on the internet. It specifies how
information is packetized, addressed, transferred, routed, and received by networked devices.
❖ Every device is assigned a unique IP address so that it can send and receive data.
❖ There are 2 versions of IP – Ipv4 and Ipv6.
➢ IPv4 dates back to the 1970s and uses 32-bit addresses – enough for 4 billion devices to be uniquely
identified.
➢ But it is no longer enough. IPv6 uses 128-bit addresses, enough for 340 trillion unique IDs.
▪ An IPv6 address consists of eight groups of 4 hexadecimal digits, separated by colons.
❖ Static IP Address: An IP address that is permanently assigned to a specific network device, such as a router or
server, and doesn’t change.
❖ Dynamic IP Address: An IP address that is temporarily
assigned to a device on a network and then returned to an
address pool so that other devices can use it.
❖ Domain Name: A human-friendly form of an IP address.
Domain names, such as www.pearson.com are much easier to
use than their equivalent IP addresses
