Chapter 3 3.1 Network Basic KMPk (C)

1. 3.0 INTERNET TECHNOLOGY
3.1 Network Basic
3.1.1 Basic Concept of Network
3.1.2 Network Architecture
3.1.3 Network Topology
3.1.4 Classification of network
3.2 The Internet
3.2.1 Overview of the internet
3.2.1.1 Introduction to the internet
3.2.1.2 The Internet Connection
3.2.1.3 Internet Service Provider
3.2.1.4 The Internet Address
3.2.2 World Wide Web
3.2.2.1 Web Browser
3.2.2.2 Web Address
3.2.2.3 Web page Navigation
3.3 Internet Services
3.4 Types of Websites
Chapter Three
1
3.0 Internet Technology

2. Chapter Three
3.1 Network Basic
3.1.1 Basic Concept of
Network
At the end of this topic, students
should be able to:
- Explain the concept of network
2

3. WHAT TO COVER?
• Definition of network
• Communication device
• Transmission media
• Advantages and disadvantages of network
3

4. WHAT IS A NETWORK?
A collection of computers and devices connected
together via communication device and transmission
media to share resources.
(Shelly,2016)
Discovering Computers : Chapter 9
Pages 470 - 471
4

5. WHAT IS A NETWORK?
A network is basically a wired or wireless
network that connects together a group of
computing resources such as computers,
printers and servers, which are located at different
places.
(Yew, Low, 2014)
Discovering Computers : Chapter 9
Pages 470 - 471
5

6. Discovering Computers : Chapter 9
Pages 460
6

7. COMMUNICATION SYSTEM
Sending
device
Receiving
device
Comm.
device
Communication
channel /
Transmission
media
Comm.
device
7

8. COMMUNICATIONS SYSTEM
• A sending device that initiates an instruction
to transmit data, instructions, or information.
• A communications device that connects the
sending device to a communications channel.
• A communications channel, or transmission
media on which the data, instructions, or
information travel.
• A communications device that connects the
communications channel to a receiving device.
• A receiving device that accepts the transmission
of data, instructions, or information. 8

9. COMMUNICATION DEVICES
• Hardware or equipment which are designed to
transfer signals or data from a sender to
receiver.
• Example: Hub, switch, modem, router, repeater,
access point, network interface card (NIC).
9

10. TRANSMISSION MEDIA
Transmission media consist of materials or
substances capable of carrying one or more
signals.
(Shelly, 2012)
• A communications channel, or
transmission media on which the data,
instructions, or information travel.
10

11. TYPES OF TRANSMISSION MEDIA
1. Wired transmission media
▪ The transmission of signals or data by means of
wire, cable, or other physical connections between a
sender (transmitter) and a receiver.
▪ Example: Fiber-optic cable, Cable television(coaxial
cable) and telephone networks(twisted-pair cable)
11

12. TYPES OF TRANSMISSION MEDIA
2. Wireless transmission media
▪ Wireless transmission media send
communications signals through the air or space
using radio, microwave and infrared signals
▪ The sender and receiver are not connected by any
electrical or optical wires/cables.
▪ Example : cellular radio, satellite, broadcast radio,
microwaves, bluetooth, infrared
12

13. ADVANTAGES OF USING A NETWORK?
Facilitating
communications
Sharing hardware
Sharing data and
information
Sharing software Transferring funds
13

14. Using a network, people communicate efficiently and easily via
e-mail, instant messaging, chat rooms, blogs, wikis, online social
networks, video telephone calls, online meetings,
video conferencing, VoIP, wireless messaging services, and
groupware.
• Sharing hardware
In a networked environment, each computer on the network can
have access to all hardware on the network.
• Sharing data and information
In a networked environment, any authorized computer user can
access data and information stored on other computers
on the network.
• Facilitating communications
14

15. • Sharing data and information
In a networked environment, any authorized computer user can
access data and information stored on other computers on the
network.
• Sharing software
Users connected to a network have access to software on the
network.
• Transferring funds
Called electronic funds transfer (EFT ), it allows users connected to a
network to transfer money from one bank account to another via
transmission media.
15

16. Discovering Computers : Chapter 9• Page 470
• Figure 9-9
16

17. DISADVANTAGES OF USING A NETWORK?
• Viruses
When computers are connected by a network, the virus can spread itself
electronically, at computer speeds.
• Network failure
If the file server fails then no-one on the network can access any files or
folders. This means that nobody can do any work. For an organization, this
would be extremely costly and disruptive.
• Slow service
As more users log onto the network and request files, send things to be
printed and open more software applications, the network can start to slow
down.
17

18. DISADVANTAGES OF USING A NETWORK?
• Cost
Every workstation needs a network interface card to enable it to be
connected to the network. Other hardware such as hubs, switches and
routers are often needed.
• Expert support required
Networks need constant monitoring to ensure that the performance is
maintained and that all of the components are working properly. This
requires specialist staff such as network managers and technicians who
will spend all of their time ensuring that the network works efficiently
whenever you need to use it. These staff add a large cost to running a
network, but without them, things would start to fail.
18

19. Chapter Three
3.1 Network Basic
3.1.2 Network
Architecture
At the end of this topic, students
should be able to:
- Explain types of network
architecture
1

20. WHAT TO COVER?
Type of network architecture
• Peer-to-peer
• Client/Server
Differentiate between
client/server and peer-to-
peer networks, and describe
how a peer-to-peer network
works
2

21. NETWORK ARCHITECTURE
• The design of computers, devices, and media on a
network is sometimes called the network
architecture
Pages 473 – 474
Figures 9-13 – 9-14
Discovering Computers : Chapter 9
3
Client/server network Peer-to-peer network

22. 1. PEER-TO-PEER
• Each computer, called a peer, has equal responsibilities
and capabilities , sharing hardware (such as a printer),
data and information with other computers.
Page 475
Figure 9-15
Discovering Computers : Chapter 9
4
Peer-to-peer networkpeer
peer

23. 2. CLIENT-SERVER
• One or more computers act as a server, and
the other computers on the network request services from
the server.
Page 475
Figure 9-15
Discovering Computers : Chapter 9
5
client
server

24. Server
Server, sometimes called a host computer,
controls access to the hardware, software, and
other resources on the network and provides
a centralized storage area for programs, data,
and information.
Client
Clients are other computers and mobile
devices on the network that rely on the server
for its resources
6

25. PEER-TO-PEER VERSUS CLIENT-SERVER
Num Peer-to-peer Client-server
1. Every user is taking care
of his/her own machine so
could be difficult to
administer the network
Centralized control by the server
can be more efficient at
administering the whole network.
2. Easy to install and
configure for the
computers in the network.
Network professionals are
normally needed to manage and
maintain the whole network.
3. Cost to install and
maintain network is
inexpensive.
Cost to install and manage the
network can be expensive.
4. Each computer has equal
responsibilities and
capabilities.
Only servers have high
responsibilities and capabilities.
7

26. Chapter Three
3.1 Network Basic
3.1.3 Network Topology
At the end of this topic, students
should be able to:
- Explain types of network
topology
1

27. NETWORKS
• A network topology refers to the layout of the
nodes (computers and devices) in a
communications network
Pages 475 – 477
Figures 9-16 – 9-18
Discovering Computers : Chapter 9
2
Star
network
Bus
network
Ring
network

28. A network topology refers to the
layout ofthe computers and devices in
a communications network.
It refers to both the physical and
logical layout of a network.
What Is a Topology?
3

29. Physical Topology
- The arrangement of a cabling is the physical
topology.
Logical Topology
- The path that data travels between computers
on a network is the logical topology.
LAYOUT OF NETWORK
4

30. Types of network topology
Three commonly used network topologies
are:
• Bus
network
• Star
network
• Ring
network
5

31. Diagram of different network topologies
Ring
Star
Bus
6

32. Bus Network Topology
- A bus network consists of a single central
cable (backbone), to which all computers and
other devices connect.
T-Connector
Terminato
r
BackboneT-Connector
Nodes
7

33. • Each devices is connected to the single central
cable(backbone) through T-Connector.
• A terminator is required at each end of the bus
cable to prevent the signal from bouncing back
and forth on the bus cable.
T-Connector
Terminat
or
Backbone
Bus Network Topology
8

34. • Transmit data, instructions, and information as a series
of signal.
• Those signals are sent as electrical pulses that travel
along the length of the cable in all directions.
Bus Network Topology
9

35. • When a sending device transmits data, the address of
the receiving device is included with the
transmission.
• If the device address does not match the intended
address for the data, the device ignores the data.
• If the data does match the device address, the data is
accepted.
• All devices receive the data but only the receiving
device accept them.
Bus Network Topology
10

36. Advantages:
1. Bus networks are inexpensive and easy to install.
2. Computers and other devices can be attached and
detached at any point on the bus without disturbing
the rest of the network.
3. Failure of one device usually does not affect the rest
of the bus network.
Bus Network Topology
11

37. Disadvantages:
1. There might be disruption when computer or
other devices are added or removed.
2. Because all systems on the network connect to
a single cable or backbone, a break in the cable
will prevent all systems from accessing the
network.
3. It is difficult to identify the problem if the entire
network shut down.
Bus Network Topology
12

38. Star Network Topology
• All the computers and other devices on the
network connect to a central device,
thus forming a star.
Hub / Switch 13

39. - Two types of devices that provide a common
central connection point to all the other
devices on the network are a hub and a
switch.
Star Network Topology
Hub / Switch 14

40. ● The device that provides a common central connection
point for other devices on a network.
● All data that transfers from one device to another
passes through the hub or switch.
● The hub takes a signal that comes from any device
and passes it along to all the other devices in the
network.
● The switch takes a signal that comes from any device
and passes it to intended devices in the network
Hub / Switch
Star Network Topology
15

41. Advantages:
1. If one device fails, only that device is
affected.
2. Devices can be added to or removed from
network with little or no disruption.
3. Easy to troubleshoot and isolate problem.
Star Network Topology
16

42. Disadvantages:
1. If the hub or switch fails, the entire network
will be inoperabled.
2. Requires more cable than most of the other
topologies.
3. More expensive because of the cost of the
hub/switch.
Star Network Topology
17

43. Ring Network Topology
● On a ring network, a cable forms a closed
loop(ring) with all computers and devices
arranged along the ring.
18

44. ● Data transmitted on a ring network travels from device
to device around the entire ring, in one direction
(clockwise or counterclockwise)
● Token passing is one method for sending data around
a ring
● Each device takes a turn sending and receiving
information through the use of a token.
Ring Network Topology
19

45. ● The token along with any data is sent from the
first device to the second device which extracts the
data addressed to it and adds any data it wishes
to send.
● Then second device passes the token and data to
the third device, etc. until it comes back around to
the first device again.
● Only the device with the token is allowed to send
data . All other devices must wait for the token to
come to them.
Ring Network Topology
20

46. Ring Network Topology
21

47. Advantages:
1. The transmission of data is relatively
simple as packets travel in one direction only.
2. Cable faults are easily located, making
troubleshooting easier.
3. The uses of token passing enables all devices in
a ring topology to share the network resources
fairly.
Ring Network Topology
22

48. Disadvantages:
1. A failure in any cable or device breaks the
loop and can take down the entire network.
2. Data packets must pass through every computer
therefore, this makes it slower.
3. A ring network can span a larger distance than a
bus network, but it is more difficult to install.
Ring Network Topology
23

49. DEFINITION ADVANTAGES DISADVANTAGES
A bus network
consists of a
single central
cable
(backbone),
to which all
computers and
other devices
connect.
Inexpensive and
easy to install.
There might be
disruption when
computer or other
devices are added
or removed.
Other devices ca be
attached or detached
without disturbing
the network.
Failure of one
device
usually does not
affect the rest
of the network.
The break in the
main cable(backbone)
will prevent all
systems
from accessing the
network.
It is difficult to
identify the problem
if the entire network
Shut down.
Summary:
BUS NETWORK TOPOLOGY
24

50. DEFINITION ADVANTAGES DISADVANTAGES
All the
computers
and other
devices
on the network
connect to a
central device,
thus forming a
star.
If one device fails,
only that device
is affected.
If the hub or switch
fails, the entire
network will be
inoperabled.
Devices can be
added
or removed from
network with no
disruption.
Easy to
troubleshoot and
isolate problem.
Requires more
cables
than most of the
other topologies.
More expensive
because of the
cost of
hub/switch.
Summary:
STAR NETWORK TOPOLOGY
25

51. Summary:
DEFINITION ADVANTAGES DISADVANTAGES
On a ring network,
a cable forms a
closed loop (ring)
with all computers
and devices
arranged
along the ring.
Transmission of
data
is simple as packets
travel in one
direction only.
A failure in any cable
or device breaks the
loop and can take
down entire
network.
Cable faults are easily
located, making
troubleshooting
easier.
All devices in ring
topolgy share the
network resources
fairly.
Data packets must
pass through every
computer, thus
make
it slower.
More difficult to
install than a
bus network.
RING NETWORK TOPOLOGY
26

52. Chapter Three
3.1 Network Basic
3.1.4 Classification of
Network
At the end of this topic, students
should be able to:
- Differentiate among Local Area
Network (LAN), Metropolitan Area
Network (MAN) and Wide Area
Network (WAN)
1

53. NETWORKS TYPICALLY ARE CLASSIFIED AS:
a) LOCAL AREA NETWORK
• Definition
• Types of LAN:
• Personal area network (PAN)
• Home area network (HAN)
• Advantages and Disadvantages of LAN
b) METROPOLITAN AREA NETWORK
• Definition
• Type of MAN
• Campus network
• Advantages and Disadvantages of MAN
c) WIDE AREA NETWORK
• Definition
• Types of WAN
• Enterprise private network
• Virtual private network
• Advantages and Disadvantages of WAN
2

54. MAN
LA
N
LA
N
LA
N
MAN
LA
N
LA
N
LA
N
MAN
LA
N
LA
N
LA
N
WA 3

55. LOCAL AREA NETWORK
LAN
4

56. • A local area network
(LAN) is a network that
connects computers and
devices in a limited
geographical area
• A wireless LAN
(WLAN) is a LAN that
uses no physical wires
5
Discovering Computers : Chapter 9
• Page 472
• Figures 9-10 – 9-
11
LAN (Local Area Network)

57. ADVANTAGES
• Easy to share devices (printers,
scanners, external drives)
• Easy to share data (homework,
pictures)
• Cost of LAN setup is low
LOCAL AREA NETWORK
6

58. DISADVANTAGES
• Power - a good LAN is required to be ‘ON’
all the times.
• Security - each computer and device
become another point of entry for
undesirables.
• If all computers running at once, can
reduce speed for each.
• Area covered is limited
LOCAL AREA NETWORK
7

59. METROPOLITAN AREA NETWORK
MAN
8

60. • A metropolitan area network (MAN) is a high-
speed network that connects local area networks
in a metropolitan area such as a city or town and
handles the bulk of communications activity
across that region.
9Discovering Computers : Chapter 9• Page 473
• Figure 9-12
MAN (Metropolitan Area Network)

61. EXAMPLE OF A MAN
10

62. EXAMPLE OF MAN
• Surveillance System
• Traffic Light Monitoring System
• Cable Network TV
11

63. TYPE OF MAN
CAMPUS AREA NETWORK (CAN)
• A campus network is a computer network made
up of an interconnection of local area networks
(LAN's)
12

64. TYPE OF MAN
CAMPUS AREA NETWORK (CAN)
• In the case of a university campus-based campus
network, the network is likely to link a variety of
campus buildings including; academic departments,
the university library and student residence halls.
13

65. EXAMPLE:
CAMPUS AREA NETWORK (CAN)
MAN
14

66. ADVANTAGES
• Efficiency and shared access.
• All the computer-owning
residents of the area have equal
ability to go on line.
METROPOLITAN AREA NETWORK
15

67. DISADVANTAGES
• It can be costly
(hardware, software, support, etc.)
• Security problems
• As the network consists of many
computers over the span of a city, the
connection can lag or become quite slow
METROPOLITAN AREA NETWORK
16

68. WIDE AREA NETWORK
WAN
17

69. WAN (Wide Area network)
A wide area network (WAN) is a network that covers
a large geographic area (such as a city, country, or the
world) using a communications channel that combines
many types of media such as telephone lines, cables,
and radio waves.
The Internet is the world’s largest WAN
18

70. ADVANTAGES
• Increase efficiency, ease of
communication, and lowered costs
WIDE AREA NETWORK
19

71. DISADVANTAGES
• Security problems
• Training costs
• Maintenance problems. Large enterprises
will dedicate personnel to maintaining their
WAN
WIDE AREA NETWORK
20

72. HOW ARE LAN, MAN, AND WAN
DIFFERENT?
21

73. HOW ARE LAN, MAN, AND WAN
DIFFERENT?
• The main differentiation among these
classifications is their area of coverage
LAN MAN WAN
LAN, MAN and WAN compared
22

74. CRITERIA Geographical Area Provider
LAN Connects computers and
devices in a limited
geographical area such as
computer laboratory.
No provider
MAN Connects computers and
devices in a metropolitan
area such as town or city.
Single provider
WAN Connects computers and
devices in a large
geographical area such as
country, world.
Multi-provider
COMPARISON:
23

75. CRITERIA Connectivity Technology
LAN Computers are located within
the same building, usually
connected through wires.
Ethernet, token
ring, FDDI, Wifi
MAN Computers connected via
telephone lines or modems,
fiber optic, cable television.
ATM, SMDS,
FDDI
WAN Computers connected via
satellite or Internet.
Circuit Switched,
Packet Switched
COMPARISON:
24