Please enable JavaScript.
Coggle requires JavaScript to display documents.
1.4: Wired and wireless networks - Coggle Diagram
1.4: Wired and wireless networks
Networks
Definition:
A
network
is
2+ computers/devices
connected together to
communicate
. They are connected via either a wired or wireless medium.
Definition:
A
standalone
is a computer/device
not connected
to a network.
Advantages of using networks
File sharing
Sharing peripherals e.g. printers
Easy to communicate i.e. email, text, call
Users can access data from any computer on the network
In larger networks, maintenance and software updates are centralised
In larger networks, anti-virus software and firewalls are centralised
In larger networks, managers can monitor their networks
In larger networks, levels of access can be controlled
Disadvantages of using networks
More costly than stand-alones, you might need extra hardware e.g. a server
Must be managed
Malware can spread more easily and faster on a network
Hacking is made easier
LANs and WANs
Definition
: A LAN is a
local area network
. It is a network that covers a
small geographic location
e.g. school/office.
Definition: A WAN is a
wide area network
. It is a network that covers a
large geographic location
e.g. over a country.
The Internet
is an example of a WAN.
Client-server and peer-to-peer models
Definition:
A client server model is where data/applications are
hosted
on a
server
and
accessed by client computers.
The
server provides for the clients
and/or manages and stores files. They control the network. Some examples of servers include file servers and mail servers.
Clients do not usually store data
; they have no control over the network.
Client-server networks are best suited to organisations with
many computers
.
Definition:
A peer-to-peer model is where all computers in a network have
responsibility
for the network and there is
no central server
.
Peers
store their own files
, which can be
accessed by other peers
on the network.
P2P networks are best suited to
smaller organisations
that have
fewer computers
.
All computers have
equal status.
They are
peers
.
Local area network hardware
Transmission media.
They carry data signals from one computer to another. In modern networks, wired media use either twisted copper wiring, or fibre-optic cable.
Point of connection
.
Switch
: Similar to hubs, except the switch forwards
traffic
to its
intended recipient
only.
Wireless Access Point (WAP)
: A device that uses a
radio transceiver
to allow wireless connections to a network. The WAP
sends wireless traffic
it receives onto the main
wired network.
Router
: Routers are used to
send data signals across the internet
. Routers collect knowledge of available routes to transmit data and determine the most suitable route for sending data.
Hub
: A small device that allows
wired devices to connect to a network
. Any traffic is transmitted to
all connected computers
.
Network interface controller (NIC)
. A NIC offers an interface port for a wired connection. A wireless NIC provides a radio transceiver.
Fact:
All networks are either wired or wireless.
The internet
The internet is a
worldwide
collection of computer
networks.
The purpose of the internet is to
enable communication
on an international scale.
Hosting
Hosting is the
storage
of files and data on a
web server
. The
URL
(uniform resource locator) for a website includes the
hostname
. Each website has a
unique domain name
.
Domain name servers
Every
website
on the internet has a
network address
, consisting of four sets of three digits.
Addresses like this are
hard for users to remember.
Instead, websites are accessed using
domain names.
A
domain name server translates
a domain name into an
internet address.
The cloud
The cloud is remote storage accessed through the internet. Users do not know where their data is stored. Users only need to know that their data is stored on a server connected to the internet.
Advantages of cloud storage
Access files from
anywhere
with an internet connection.
Access can be
granted to others
so they can also access your files/data.
Reduced need for back-ups.
Disadvantages of cloud storage
No guarantee your files/data isn't being
accessed by unauthorised personnel
.
No guarantee
your
data is being backed up.
No access without an internet connection.
Virtual networks
Virtual network servers create a network that has
no physical connection
, but one that
allows communication
.
Some organisations use virtual networks to enable users
at home
to connect to the organisation's data and facilities.
A virtual network is a
network
of computers
connected via the internet.
Factors affecting the performance of a network
Bandwidth of transmission medium
: Bandwidth is a measure of the
amount of data
that the medium can
transfer
over a
given period
of time. Different types of network traffic have
different bandwidth requirements
and some switches can
adjust
for this.
Type of network traffic
Number of devices connected
Latency
: A measure of
how long it takes a message to travel from one device to another across a network
. A network with low latency experiences few delays in transmission, whereas a high latency network experiences many delays. The more delays there are, the longer it takes to transmit data across a network.
Number of transmission errors
: When devices try to communicate with each other at the same time, their
signals collide
with each other and the
transmission fails.
The
greater the number of devices
on a network, the
longer it takes to transmit
a message.