Doman's Sections

Basically, the collection of elements needed
to enable information exchange between
people, systems, or people and systems
◦
◦
◦
◦
2
hardware
software
transmission media
services
©2005, L.A. DeNoia
Customers
Telecommuters,
Travelers
Branch
Offices
Internet
Corporate
Headquarters
3
Small
Businesses
©2005, L.A. DeNoia
Suppliers
 Printers
 Servers
 Proxy
Servers
Filters requests between clients and other networks

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models

Twisted-Pair
◦ used in your house for the phone
◦ used by a DSL Modem

Coaxial Cable
◦ used in your house for cable TV
◦ used by a Cable Modem

Fiber Optic

Physical and Data link layers
◦ Map bit values to wavelength

Standard for transmission of wired networks
◦ Ethernet

Bus Network

Token Ring

Star
Bus Network
 Token Ring
 Star

Bus Network
 Token Ring
 Star

Bus Network
 Token Ring
 Star

◦ Advantage:
 Fault Tolerant
◦ Disadvantage:
 lots of wires


Transmission media –
Radio waves
Hardware required:
◦ Wireless network
adapter

Physical and Data link layers
◦ Map bit values to wavelength

Standard for transmission of wireless networks
◦ 802.11 A through N
Wireless Formats
A
• not on same frequency as phones
• short range
B
•
•
•
and G
longer range and faster than A
cordless phones can interfere
B is common in airports, etc.
N
• fastest, good range
• not compatible with B and G
wireless hosts
r laptop, PDA, IP phone
network
infrastructure
Access point
r typically connected to
a wired network
Ad hoc mode
r no base stations
r nodes can only
transmit to other nodes
within link coverage
r nodes organize
themselves into a
network: route among
themselves

Switch
 Connects local devices

Router
 Connect networks.
 A router links computers to the
Internet.
 A router acts as a dispatcher,
choosing the best path for
information to travel so it's
received quickly.

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models

LAN - Local Area Network
◦ small area (e.g. a building)
◦ small number of machines

WAN - Wide Area Network
◦ large area (e.g., Comporium coverage)
◦ usually a collection of LANS

Others
CAN – Campus area Network
◦ PAN - personal area network
◦ MAN - metropolitan area network
computer
or PAN
LAN
WAN
LAN
CAN
L.A.DeNoia, ©2008
20

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models
Consider friend frequently changing
addresses, how do you find her?
 search all phone
books?
 call her parents?
 expect her to let you
know where he/she
is?
I wonder where
Alice moved to?
home network:
Where Alice lives
Permanent
address
Infamous
internet
home agent
(router)
entity can always
find Alice
Bob’ s network
Visiting network:
High School reunion
home network:
Where Alice lives
Permanent
address
home agent
(router)
entity can always
find Alice
Infamous
internet
Bob
Visiting network:
High School reunion
home network:
Where Alice lives
home agent
(router)
entity can always
find Alice
Infamous
internet
Bob
When mobile user moves to another network
the following happens
1. Mobile user registers with the new network
2. New network tells the home network it knows
where user is.
3. Home network updates care-of-address for
mobile user
When a call is made to the mobile user
Packets continue to be forwarded to mobile user but
with new care-of-address


This design makes changing different
networks transparent
ongoing connections can be maintained!
6: Wireless and Mobile Networks
627

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models
The “big I”
Internet
Regional
network
ISP network
ISP network
Regional
network
ISP network
Web
client
Web
server
©2005, L.A. DeNoia

The Internet
=
◦ a network of computer networks

"The Web"
◦
≠ "The Internet"
The World Wide Web is just one of many services
that use the internet.

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models
All communication activity is governed by protocols
a human protocol and a computer network protocol:
Hi
Hi
Got the
time?
2:00
time
rules for conversation and behavior
Get http://www.winthrop.edu
<file>

Military proposed a standard protocol
between routers
 Underlying protocol for internet: Internet
Protocol IP

1969 – ARPAnet from US Military
ARPAnet 1975 pic from
som.csudh.edu

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models
36 / 13

Routing of Packets
message
Orlando
Rock Hill
Steve
message
mes
sag
e
Steve's
Mom and Dad

Designed to block unauthorized
access into and out of the network.

Implemented as either hardware or
software
Filters the information coming
through/going to the Internet
connection into/from your
private network or computer
system.
If an incoming packet of
information is flagged by the
filters, it is not allowed
through.
Image and definition from www.wikipedia.com
All communication activity is governed by
protocols

Protocol between Routers
◦ Underlying protocol for internet: Internet Protocol

Protocol between Applications
◦ TCP, UDP, AppleTalk, Novelle, protocol suite
IP

http://www.youtub
e.com/watch?v=H7
60U3QZocs

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models
System of server machines scattered
throughout the world
Support the protocol that allows them to
share and read specially formatted
documents
My browser
Rio de Janeiro
Server Farm
Paris
Colorado
All communication activity is governed by
protocols


Protocol between Routers
◦ Underlying protocol for internet: Internet Protocol IP
Protocol between Applications
◦ TCP, UDP, AppleTalk, Novelle, protocol suite
 World Wide Web Protocol:
◦ Hypertext Transfer Protocol : HTTP
Client
browser
Web
server
L.A.DeNoia, ©2008
How do systems
find the web
page they are
looking for?
Uniform Resource Locator : URL
45 / 13
http://faculty.winthrop.edu/domanm/default.htm
I want a web file (could be "ftp")
domain name
machine at that domain
directory on that machine
file inside that directory
46 / 13
http://faculty.winthrop.edu/domanm/default.htm
Machine on the internet
File on that machine
So…
Are these legitimate web pages?
www.bankofamerica.com.signin.springboard.ru/verify.htm
www.bankofamerica.com/spyware/verify/password.htm
People: many identifiers:
◦ SSN, name, passport #
Internet hosts, routers:
◦ IP address (32 bit) - used
for addressing entities
 IPv6 new and better version
Domain Name System
Example:
Humans use: www.winthrop.edu.
Routers need: 199.79.254.163
How is the map between IP addresses and name done?
root
.com
.org
.edu
ibm ...
ietf ...
.us
winthrop...
faculty
48
wingspan.winthrop.edu
wingspan
acc
L.A.DeNoia, ©2008
...
•ICANN coordinates unique computer identifiers across the world.
Without that coordination we wouldn't have one global Internet.
•ICANN was formed in 1998.
It is a not-for-profit public-benefit corporation with participants
from all over the world dedicated to keeping the Internet
secure, stable and interoperable. It promotes competition and
develops policy on the Internet’s unique identifiers.
•ICANN doesn’t control content on the Internet.
http://icann.org/en/about/
49
50 / 13

Do it yourself
1. buy a server
2. obtain an IP address
3. register your name and address with ICANN
internet corporation for assigned names and numbers
OR
 Contract with a "Server Farm"
1. google "domain hosting" to find a provider
2. pay a small monthly fee

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving

Internet
◦
◦
◦
◦

What is the internet
History
How data moves through the internet
Web Addresses
Network Application Models
Client –Server
Connections
Peer-to-Peer
Connections
Web Browsers
(WWW)
Games
 Warcraft
 Skype
 File sharing

The “big I”
Internet
Corporate A
network
ISP network
ISP network
Corporate C
network
Corporate B
network
Web
client
Web
server
©2005, L.A. DeNoia

The Internet is currently neutral.
◦

The Case For Neutrality:
◦

Every packet is equal to every other packet,
regardless of type, destination, or owner.
Neutrality ensures a level playing field.
The Case Against Neutrality:
◦
The telecom companies own the pipes, so they
should be allowed to manage them and charge
for them however they want.
59 / 13


DNS: Domain Name
System

 eg: winthrop.edu

ISP
Client/Server
Peer to Peer
and
 most internet traffic is
client/server
IP Address
 eg: 10.2.0.164 is the IP
address for Winthrop's
main web site
◦ Internet Service
Provider

Domain Name

URL
◦ Uniform Resource
Locator

Network topologies
◦ Wired and Wireless networks


Basic Networking Setups/Types
Wireless Mobility
◦ How you find a friend who keeps moving


Network Application Models
Internet
◦
◦
◦
◦
What is the internet
History
How data moves through the internet
Web Addresses
 Adding
style
 Bring
images, navigation and
your laptop