Transcript Lesson 11 PowerPoint - S

AOIT
Principles of Information Technology
Unit 4, Lesson 11
How Data Travels the Internet
The Internet Is the World’s Largest Computer Network
The Internet is a vast
network of linked
computers.
Does this artist’s
interpretation of the
Internet remind you of
anything?
All Data Travels the Internet as Packets
Email Packet
•
•
Every web page that you view
or file that you receive over the
Internet comes as a series of
packets.
The chart on the right shows
the breakdown of a generic
email packet.
Header
Sender’s IP address
Receiver’s IP address
Protocol
Packet number
Payload
Data
Trailer
Data to show end of
packet
Error correction
Most People Connect to the Internet With a LAN
A LAN diagram, showing IP addresses and how
each computer connects to the Internet
Each Device on the Internet Has an IP Address
Every device on the
Internet has an IP
address.
This control panel
shows a computer’s
IP address.
Can you find your
computer’s IP
address?
Data Packets Travel Many Steps Between ISPs
Packets take
many “hops”
to reach their
destinations.
“Ping” a Computer to Check Your Connection
Pinging a
computer can tell
you if your
connection to the
other machine is
working.
The Internet Is Complicated Yet Effective
The Internet uses a complicated yet highly effective
system for sending data.
Every day, billions of packets travel the Internet
delivering data to millions of users around the
world.
Image Credits
The artist’s representation of the Internet on Slide 2 is available at
http://en.wikipedia.org/wiki/Image:Internet_map_1024.jpg and is reproduced here under the
terms of the Creative Commons Attribution 2.5 License.