Networks Flashcards
What is a Network?
A network is a connection
of two or more devices
that allows them to share
information and
resources
What is PAN
Personal Area Network —
connects devices in a small area, like a phone and a smartwatch.
what is LAN
Local Area Network —
connects devices in a limited area, like a school or office
What is WAN
Wide Area Network —
connects devices over a large geographical area, often across cities
or countries.
Is speed and stability important on your network?
Wired Networks provide greater speeds and
stability than wireless networks.
Wireless networks are more prone to
interference from other electronic devices
and as their data needs to be encrypted this
can make transmission slower.
How important is it that the data being sent is secure?
On wired networks data is transferred using
physical cables. These are harder to tamper
with and more secure.
Wireless networks transmit data is a sphere
of 50m around the WAP. Anyone who can
hack the password can access this data
without even needing to be in the building
The different arrangements of computer connections and devices are
called topologies.
Bus
Ring
Star
Mesh
What’s a bus?
Has a central cable called a backbone on which all
other devices are connected. Data can travel in any
direction and as a result collisions are common
resulting in data loss
What’s a Ring
Each device is
connected to at
most two other
devices.
Unidirectional
rings - data
travels in one
direction
Bidirectional
rings - data
travels in both
direction
Token- ring networks a
device can only
communicate when it has a
special token, this reduces
the chances of data
collisions
If a device is offline or a
cable is faulty the network
will fail!
What’s a star?
A switch sits in the middle of the
network and all devices connect to it.
The switch redirects all data to the
correct destination device.
Star networks are easy to scale up (to
add more devices to).
If the central switch fails then all
devices connected to that switch will
be offline.
What’s a mesh
In a mesh network, there is no central
communications point. Instead there are
multiple paths between the communication
devices (e.g. switches and routers) that form
the network.
This means that there is no critical point of
failure as every communication path has
several alternative pathways.
The internet is a classic example of a mesh
network.
Why do people use network?
Networks have revolutionised our ability to communicate. There are many different communication systems, for example:
text (SMS) message
email
instant messaging
internet telephony
What are advantages of Networks
The ability to share expensive hardware devices between multiple users
The ability to share files
The ability to have multi-user systems
The ability for the organisation to track what users are doing (this can of course be a disadvantage for the individual user)
The ability to back up files centrally
The ability to deploy and upgrade software centrally
What are disadvantages of Networks
Extra hardware costs (cabling and connection devices)
The cost of having to have employ someone to look after the network (depending on the size of the network)
Greater security risks
what are many different types of network.
A personal area network (PAN) is the term given to connected devices that are located within a few metres of each other.
A local area network (LAN) is a single network that is located in a small geographical area such as someone’s home, an office, or to cover a school site.
A wide area network (WAN) is a network that connects two or more networks over a wider geographical area.
