The Internet & WWW topic 11

topic 11
The Internet & WWW
the Internet
• worldwide connection of thousands of computer networks.
• these networks use a common language to communicate.
• transmission Control Protocol/Internet Protocol (TCP/IP)
– enables instantaneous transmission/reception of digital data
• the Internet is a cooperative community of networks.
• no particular body owns the internet.
the network
• the Internet is structured in an ‘hierarchical form’.
• more than 500,000 networks in more than 150 countries.
communication channels carry data on the Internet backbone
bandwidth- is a channel’s data carrying capacity.
bandwidth =
no. of bits of information passed/second
different Internet channels
phone Lines (twisted pair)
coaxial cable
fibre Optics
fibre-optic cable
the Internet in Australia
• Australian telecommunication agencies carry internet traffic on
the Telstra backbone
• Internet provided and maintained by Telstra Internet Direct
• Telstra’s domestic internet capacity
– 1997 100Mbps
– 1999 1,000Mbps
– 2004 10,000Mbps
broadband connectivity
- fibre optic
- satellite
- microwave
– data transmission protocol on which Internet is based.
– breaks Internet data into small ‘Information Packets’.
– each packet contains the data and the address where it is
being sent.
• Routers
– computers routing ‘Information Packets’ through channels
to destinations.
– keeps records of original data for rearranging packets in
correct order on arrival at destination.
internet traffic
Internet addresses
• IP address
• each computer on the Internet has a unique IP number.
• it consists of ‘4 bytes’, numbers ‘0 and 255’, separated by
• eg-
• e-mail is electronic transmission and reception of messages
between users on the Internet.
• each user has a unique ‘e-mail’ address.
– eg-
– where ‘john’ is username, ‘’ is the domain.
• an e-mail consists of
– ‘Title:’ or ‘To:’
– ‘Body’
– ‘Signature’
peer 2 peer
• two (or more) computers linked directly to each other
via their IP numbers
• allows real-time communication between machines
• some systems use servers to identify machines on
the network
• examples:
MSN Messager
Skype (voice over IP)
voice over IP
voice messages sent as packets over the Internet
computer to computer
computer to phone
operates on local area networks
many extra services
• enables people to see and speak
• previously required dedicated lines
• bandwidth hungry
remote control
• Internet used to control devices remotely
World Wide Web
• most commonly used method of accessing
information the internet
a browser
assignment submission
5 MB limit
all files in one folder
create archive of the folder
upload to SCAM syte to tutor
only 1 upload possible, upload to spare is a problem
• keep a copy in case!!
covering lecture content
2 hours + 5 mins reading
20 multi-guess (10 marks)
20 short answer (20 marks)
– brief responses and point form is encouraged