For a network to work correctly it needs to have important items as listed above. If there is a breakdown in any one of these components, the network won't work.
Clients (people, school students) want to use a network to surf the web, conduct their jobs, be entertained, print out documents and much more.
brings the internet into the network, eg a school, via a phone line
is the converter from analogue to digital (modulates the analogue phone line signal to digital so the computer can understand it)
is the converter from digital back to analogue (demodulates the digital signal back into analogue to go over the phone line)
Why is a modem needed? If the whole internet was digital from your computer to all other computers on the internet, then a modem would not be needed. But it isn't, so we need the conversion from analogue to digital to occur.
connects networks
connects network from one location to a network from a different location
ie connects a school network to the public telephone network
it connects via an ip address eg 10.201.201.1
the server is a computer
checks username and passwords so only authorised users can access the network
can have many servers
a server for authentication ie check username and passwords
a server for supplying the internet, proxy server
a server to supply printing
a server to save files for clients on the network
it is the server that distributes these resources to the clients (people)
is a device that a room full of computers can connect to
it is the next step in the chain from the classroom computer NIC
ie from NIC, through cabling to the switch
the switch then sends the data to server. (often with optic fibre)
connects a computer to a network
in a desktop computer it is located where the ethernet cable clicks in the back
in windows computers it often has lights, green, orange which flicker when data is transmitting
Create a graphic with labels to describe a network with the above components
Learn more from wikipedia
A network topology is a structure for the network. So a Star network is a structure that looks like a star shape based on the set out of the parts.
A computer not connected to other computers is called a stand-alone computer.
A computer connected to other computers is called a networked computer.
Peer to peer = client to client = user to user = no central server
has a central point, normally a switch
has connections to that switch from outer points, usually computers
is the most common shape for a network
the central switch then sends the data for those connected computers to a server which provides the data back to those computers. Data such as ; internet uploads and downloads, file saving and much more.
to do this you need 2 things; a wireless adaptor on your device and a wireless access point
laptops have the wireless adaptor or wireless cared built in, as do smartphones
the wireless access point then goes to the server and provides resources such as the internet and more.
a computer network is made up of computers
the central computer is called a server
all other computers connected to it are called clients
the central server provides all the resources for the client computers. Resources like; internet, file saving, printing and more.
a computer network is made up of computers
no central computer exists for peer to peer
each computer can share a resource eg a printer can be plugged into one, which is then shared to others.
a peer computer shares resources and also uses resources
Create graphics that show the above network configurations.
Learn more from wikipedia
the concept of networking is the idea of coming together
a computer network is a collection of computers that are joined together
it does this by creating links which allow communication between connected devices
the link is created though hardware and is setup using software (eg TCP/IP)
it involves sending a request to use a network resource, eg asking for a file stored on the server
it also involves receiving from the the network resource eg receiving the file
networking will continue to work as long as the connections still work
to share resources such as; internet, printers, data files, scanners, photocopiers, email, messaging
it allows people to stay in touch with friends, work mates, family and more
it allows people to do their jobs
it allows people to conduct hobbies and much more
it allows people to be entertained
it is becoming so popular that even parts of our house and car are now networked;fridge, car
it is faster to communicate
we can communicate from different devices, smartphones, tablets, laptops, desktops.
to share resources in an office = saving money, ie no need to buy a printer for everyone in the office, just share one.
to share resources at school eg a teacher puts a file on the network for the students to download and use OR a student uploads an assignment to a teacher on the school network.
to work together on the same project; open the shared project and each person can contribute to it from the one location
networked data is available from any computer on the network
a single point of failure results in a network that doesn't function properly
a network administrator must be used
security issues; eg a virus can get to the computers which could lead to malfunction
privacy issues; eg a virus can get to the computers which could lead to spyware obtained personal details
Study by writing down the main points in the topics above in your own words.
Study again by reading your notes again > deleting your notes > rewriting your notes > comparing to notes on this webpage
Learn more from wikipedia, internet of things,
For personal use in the home you need to have a network adapter, a router and an access point.
your wireless device needs to be able to connect to a network
to do this it will need a wireless card
it is the wireless card that communicates to the router
this needs to be setup with a username and password to match the router
the company who supplies your home internet, will usually supply a router
the router will have a built in modem to allow the internet connection to happen
the router will also send and receive the data so you can communicate on the network
the location where the telephone line comes into your house is the access point
this is a telephone socket on the wall
this must connect to the router
Create graphics to show what this wireless setup would look like in your house.
Learn more from wikipedia
For personal use in the home you need to have a network adapter, a router and an access point. Will these items work on your computer?
Will there be hardware compatibility issues? (One thing won't work with another thing)
Will it be usable?
What is an Internet Service Provider (ISP) and which one do you use?
Do you need to share the internet to more than one device in your home?
an internet service provider is a company who you pay to provide internet to your house
they need you to have a working phone line to your house, as well as a computing device to connect to
alternatively, you can use a wireless router which connects to your local wireless towers
they will give you a router (with a built in modem)
they will set it up for you, for a cost
or you can set it up, with telephone help from them
Which one? Ask your friends, research on the web. There are plenty to choose from.
Questions for an ISP
What type of internet packages do you offer?
Is optic fibre available in my area?
Is broadband available in my area?
Is dial up available in my area?
Do I need to pay line rental?
What is the total cost?
What usage and speed do I need?
Sometimes when you buy something, it won't work because it doesn't match the system you want it to go with.
eg You might buy a printer, but after trying to connect it, realise that it won't work with your system.
A common reason may be the drivers (software to make the hardware work) aren't the right ones.
Is your network adapter compatible? If you bought it with the machine, it should work.
Is your router compatible? It should be. These days ISPs will supply a router as part of a 'deal'. If it isn't, then the ISP support line will give you help to setup the correct drivers to make it work.
Can I use an old router that a mate gave me? Yes you can try, BUT...
You won't get support from your ISP
You may not be able to get the drivers to make it work
Yes it can be usable, but only if you make it compatible by getting the correct software (driver) to make it work.
It will work, with the correct software (drivers) matching the hardware.
Note: there may also be username and password issues but that is not hardware related.
What is needed to make an old router work with your current computer?
What is also needed to make that router work with an ISP?
Learn more from wikpedia
For a network to work correctly it needs to have rules to make the system work.
These rules are called protocols. for example when you type in a web address, it is the HTTP protocol that is working
A protocol is a set of rules that allow a computing device to communicate with another computing device
is the standard to connect to a web server
is the standard that divides your expected webpage into smaller 'packets'
gives an address for each packet
gets sent
is the standard for receiving a webpage
it does error checking to make sure some of the packets aren't missing
it reassembles the 'packets' into the correct sequence for the expected webpage
now the browser is ready to display the webpage, BUT, we need HTTP for that
is the standard to transfer hypertext
HTTP is the request, response protocol
a client requests, yes via typing http... into the web address bar
if the web server can proceed with the request, ie the web address is correct, it will send the page
if the server cannot proceed with the request, ie the web address is wrong, it will send an error page 404 page not found
is the standard to transfer hypertext, but with a secure connection
it is secure because data passes within a connection encrypted by SSL
a web server will authenticate to see if the password, called a digital certificate public/private key matches,
if this key setup matches, it remains secure and you can get into the webpage
is the standard to access data over a mobile wireless system
it can access all operating systems, on all mobile devices such as smartphones, tablets, laptops
Wireless Markup Language (WML) delivers the content to the smaller display screens
WML is similar to HyperText Markup Language
What is a protocol?
How is HTTP different from HTTPS?
How does TCP/IP work?
How does HTTP work?
Learn more from TCP/IP at wikipedia, HTTP at wikipedia, HTTPS at wikipedia, WAP at wikipedia, SSL explained at digicert.com.SSL more
communication standards state the expected characteristics for that type of communication.
802.3 is a standard specification for ethernet
802.11 is a standard specification for wireless
standard ethernet
commonly uses twisted pair
Fast ethernet
Cat 5 twisted pair cable or fiber optic (not coax)
Gigabit ethernet
uses full duplex operation with dedicated pairs for transmission and receive
need to have full-duplex NIC
must use a switch (not a hub)
Ten-Gigabit ethernet
maximum distance covers 300-400 metres
full duplex mode only
uses optic fibre only
Name: 10Base5 or thicknet was a first version of ethernet
Cable: thick coax
Max Cable Run: 500 meters
Segments: 100
Topology: Bus
10 Mbps over thick coaxial cable for about 500 metres
Name: 10Base2 or cheapernet was a first version of ethernet, but with thin coax
Cable: thin coax
Max Cable Run: about 200 metres
Segments: 30
Topology: Bus
10 Mbps over thin coax for about 200 metres
Name: 10BaseT (the T stands for twisted pair)
Cable: twisted pair
Max Cable Run: 100 meters
Segments: 1
Topology: Star
10 Mbps over unshielded twisted pairs with RJ45 connectors
Name: 10BaseF (the F stands for Fibre Optic)
Cable: Fibre Optic
Max Cable Run: 2000 metres
Segments: 1
Topology: Star
not expensive to implement
simple to join, connect to switches
flexible cabling
only good for light loads of 30% capacity
data packet collisions cause many resends
one fault and the whole system goes down
July 1999
up 11 Mbps
on 2.4 Ghz
Ads = low cost, good signal, range 35m indoors, 120m outdoors
Disads = slow speed, some interference, can't work with 802.11b
July 1999
up to 54Mbps
on 5 Ghz
Ads = faster than 802.11a, little interference, range
Disads = high cost, shorter range or length of signal, can't work with 802.11a
2002/2003
up to 54 Mbps
on 2.4 Ghz
Ads = faster than 802.11b, good range, can work with 802/11b
Disads = higher cost than 802.11b, some interference
2009
up to 300 Mbps
2.4 Ghz and 5 GHz because uses multiple signals and antennas
channel width of 40 MHz
MIMO Multiple Input, Multiple Output with 4 spatial streams
Ads = fast speed, best signal range of length of signal (max 100m), little interference
Disads = cost more, can interfere with 802.11b and 802/11g
2014
from 430 Mbps to 2 or 3 Gbps
on 5 MHz
MIMO with 8 streams each of width 80 MHz
uses beamforming to direct signal to improve communications, uses smart antenna which track the device Ref: Extreme Tech
Ads = can work with 802.11g/802.11n, very fast, range max 50m,
Create graphics that contribute to a class poster for validation techniques. Start this by going to an online form and taking a screen shot.
Learn more from W3C standards, ieeee ethernet, ieeee wireless,
can be a server that filters incoming data from blacklisted IP addresses
can be a proxy server, the gatekeeper for what packets of data get in or out
can be software on your computer to protect who accesses your computer
you can ban certain protocols, eg File Transfer Protocol (FTP) which can upload dangerous files to computers
anti virus software is essential these days to prevent hackers getting to your home computer
keep the software updated regularly
turn off your computer if you are not using it
avoid sites which are known to have viruses, eg file download websites such as free game sites, porn sites, torrent sites, Facebook
never click a link in an email from someone you don't know
is an access code to get into a computer or device
better passwords are NOT just dictionary words eg 3nter
better passwords are longer passwords, the longer the better, eg 15 characters or more will take a long time to crack
if you have important data, use a strong password
eg of a strong password; !Liv3@al0velyPlAce = Iliveatalovelyplace = I live at a lovely place
don't use a password that is a family member or pet
stop anyone from getting into the building
keep the doors locked
stop anyone from taking the computer
use a lock down system with a cable, example shown HERE
Create passwords that use unusual characters. eg @ for a, 0 for o, 3 for e, ( for l, etc
Give them to your school friends to guess what they are. eg What is @pp(3 Did you get apple?
Discuss the best passwords to use with your teacher.
Learn more from wiki about passwords, wiki about firewalls, wiki about passwords
A computer can be used to send or receive information.
It is the network that does this.
no network = no internet
Movement of data by upload or download is called transmission of data.
For this data to move, it needs to go through the air or through cables.
optical fibre cabling has very long strands of glass inside a cable
data travels inside the strands of glass as pulses of light
the size of the strand of glass = the size of a human hair
data = light
each optic fibre cable can carry 1 or more strands of glass
centre part of the optic fibre cable is the strands of glass
outside of this is a cladding to reflect the light back into the cable
outside of this is buffer coating to protect the cable
disadvantages; expensive, difficult to join
advantages; fast, no interference
very commonly used in networks today
contains 4 pairs of wires
is set on the 802.3 standard
twisted every cm in a tight twist to minimize electrical interference
sometimes shielded completely in aluminium foil to prevent electrical interference
has an rj-45 male connector on each end
plugs into an rj-45 female connector wall
data speed on a category 5 (cat5) cable less than 90 metres is capable of 100 Mbps
data speed on a category 6 (cat6) cable less than 90 metres is capable of 1000 Mbps
for 100 Mbps 2 wires are commonly used.
for 1000 Mbps all 4 pairs of wires are commonly used
not commonly used in networks today
used in bus networks
consists of 2 wires
a centre wire, surrounded by a plastic insulator
an external braided wire, which surrounds the plastic insulator
finally a protective covering around the cable
data speed on a coaxial cable less than 180 metres is 10 Mbps
used for mobile clients
it uses radio waves
must have a transmitter and a receiver to send / receive data
the devices must have a wireless adapter to transmit and receive
must be configured prior to working, usually a network name, username and password
the receiving antenna in a school location is a wireless access point (WAP)
hot spots are common 'free' wireless locations that are configured to have no username and password
the working range indoors is up to 20 metres depending on wall construction and type of wireless setup
the working range outdoors is up to 100 metres, depending on the type of wireless setup
wireless setup is based on a standard called 802.11
it has additions onto the number 11 for newer and improved versions eg 802.11a, 802.11b, 802.11g, 802.11n
wireless operates around 2.4 Ghz range, or around the 5 Ghz range
used for short distances up to 10 metres
uses short range radio waves at the 2.45 Ghz frequency
is a small microchip that can transmit and receive data
it is very common in mobile devices
the bluetooth controller is the Link Manager (LM)
the Link Manager identifies other bluetooth devices, creates links, sends and receive data
the Link Manager also controls the operation mode, eg standby (wake each 2 secs to listen), master/slave (initiating link=master), inquiry (causes devices to ID), park (wakes at intervals, listens syncs), hold (power saving, but discoverable)
Locate the wireless access points in your school. Draw a rough map of these wireless access point locations.
Make up some advantages and disadvantages for the wired and wireless systems.
Explain types of wired networking in your own words.
Explain types of wireless networking in your own words.
Learn more about optical fibre from youtube,
For a network to work correctly it needs to have connectivity.
But. How fast is this connectivity?
That depends on the type of connectors and transmission medium.
Transmission of data is the speed of the data moving from one place to another.
it is measured by how many units pass through the network in a given time
commonly this is bits per second or bps
some people call it upload or download speed, or bandwidth
you may have heard it called megabits per second
bits per second = bps
kilobits per second = kbps = 1000 bits per second or 1024 bits per second
megabits per second = mbps = 1000 kb per second or 1024 kb per second
wireless - range; if close, it will transmit faster, concrete walls, metal plates or chicken wire in walls; goes very slow or stops, interference from microwave ovens, other electrical devices
old copper phone lines - straight wires in plastic sheath, interference from other wires
twisted pair - twisted wires in plastic sheath, less interference from other wires because of the many twists
optic fibre - light transmitting pulses; not influenced by interference
other clients online cable speed greatly reduced by more clients online, wireless speed greatly reduced by more clients online
dial up = 56 Kbps
ADSL = 512 Kbps- 2Mbps
cable = 512 Kbps- 2Mbps
Satellite = 512 Kbps
Optic Fiber = 100 Mbps (but only with no copper wires in the system anywhere)
the download rate and time are visible at the bottom of the screen when downloading off the internet
many web services can measure your upload and download speed eg whatismyip speedtest.net
Choose one of the topics from above.
Explain it to a friend in the class. The friend and you discuss it further.
As a pair, you tell the class.
Learn more from bit rate at wikipedia, by device medium at wikipedia
For a network to work correctly it needs to be protected from attack.
is a security item to protect a computer
it stops attackers from getting to your computer
on a home computer you can turn on firewall protection
anti virus software is essential these days to prevent hackers getting to your home computer
keep the software updated regularly
turn off your computer if you are not using it
avoid sites which are known to have viruses, eg file download websites such as free game sites, porn sites, torrent sites, Facebook
never click a link in an email from someone you don't know
Make a list of the 5 worst websites for viruses.
Explain how you can turn on firewall protection on your home computer.
Explain how you can avoid getting viruses on your computer.
Learn more... from wikihow on how to turn on or off a firewall