Esoft Computer Studies - Diploma in Information Technology - (Module V) Fundamentals in Networking (Template - Virtusa Corporate)

1. Diploma in Information Technology
Module IV: Fundamentals in
Networking
By: Rasan Samarasinghe
Esoft Computer Studies (pvt) Ltd.
No 68/1, First Floor, Main Street, Pallegama, Embilipitiya.

2. Content
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What is a computer network?
Types of computer networks
Personal Area Network
Local Area Network
Metropolitan Area Network
Wide Area Network
Networking Topologies
Physical Topologies
Physical point to point
Physical bus topology
Physical ring topology
Physical star topology
Physical mesh topology
Physical hybrid topology
Logical Topologies
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Logical bus topology
Logical ring topology
Switching implemented…
Networking Cables
Coaxial Cables
Twisted Pair Cables
Fiber Optic Cables
Networking Devices
NIC-Network interface card
Hub
Network Switch
Router
Bridge
IP Address
Activities

3. What is a computer network?
Computer network is an interconnection of
two or more computers and other devices.
Devices on a network can be linked by cables,
telephone lines, radio waves or infrared
waves.

4. Advantages of computer networks
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Files sharing
Devices sharing
Communication
Services sharing

5. Disadvantages of computer networks
• Virus attacks
• Hacker attacks
• Failures of a server may effect to the entire
network

6. Types of computer networks
Based on the network size, networks can be
categorized into several types
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4.
Personal Area Network (PAN)
Local Area Network (LAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)

7. Personal Area Network (PAN)
PAN is wireless network connected with
mobile devices such as mobile phones, PDAs,
Bluetooth printers, Headsets, etc. The
technology using in here is Bluetooth or
infrared.

8. Local Area Network (LAN)
• Coverage is about within 1km.
• Ex: a company network within a building or
may be within two or more buildings

9. Metropolitan Area Network (MAN)
• Coverage is about more than 1km and less
than 10km.
• Ex: A network of a large town

10. Wide Area Network (WAN)
• Coverage is about more than 10km.
• Satellites may be use to expand this network.
• Ex: Internet

11. Networking Topologies
Topology is the way that we connect
computers and other devices. In other words
topology is the map of the network

12. Networking Topologies
Topologies can be divided into two sections
1. Physical Topologies
2. Logical Topologies

13. Physical Topologies
Physical arrangement of the network is known
as physical topology
Ex:
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Physical point to point topology
Physical bus topology
Physical ring topology
Physical star topology
Physical mesh topology
Physical hybrid topology

14. Physical Point to Point Topology
This is the simplest topology that uses a
permanent link between two end devices. It
also known as peer to peer topology.

15. Physical Point to Point Topology
Characteristics
• Using twisted pair cables
• RJ-45 connectors
• Maximum segment length is 100m

16. Physical Point to Point Topology
Advantages
• Low cost
• No additional devices or servers needed
• Easy to implement

17. Physical Point to Point Topology
Disadvantages
• Maximum 2 computers can be connected
• Cable breaks will effect to the whole network

18. Physical Bus Topology
Each computers and devices are connected to
a single cable called “backbone”.

19. Physical Bus Topology
Characteristics
• Channel accessing method is CSMA/CD (carrier
sense multiple access / collision detection)
• Both thin net and thick net coaxial cables are
used
• Segment length of thin net coaxial cable is 200m
• Segment length of thick net coaxial cable is 500m
• BNC Connectors are used
• Maximum data transfer speed is 10mbps

20. Physical Bus Topology
Advantages
• Easy to implement
• Easy to expand
• Low cost (no additional devices)

21. Physical Bus Topology
Disadvantages
• Maximum speed is 10mbps only
• Number of PCs will effect to the performance
of the network
• If backbone breaks, the entire network will
down
• Not suitable for heavy traffic
• Hard to find faults of the network

22. Physical Ring Topology
Each computers and devices are connected
each other forming a large circle.

23. Physical Ring Topology
Characteristics
• Channel accessing method is “Token Passing”
• Using coaxial or twisted pair cables
• Connectors used BNC or RJ-45
• Maximum data transfer speed is between 4 16mbps

24. Physical Ring Topology
Advantages
• No collisions are occurred
• No need of a server
• Even the load of the network increases, it still
perform better than bus topology.

25. Physical Ring Topology
Disadvantages
• If the cable breaks, entire network will be
down
• If one station goes down, it will be affected to
the entire network.
• Low speed

26. Physical Star Topology
All the components of the network are
connected to the central device called hub or
switch

27. Physical Star Topology
Characteristics
• Twisted pair cables are using
• Connectors are RJ-45
• Channel accessing method is depends on the
central device

28. Physical Star Topology
Advantages
• Higher data transfer speed than previous
topologies. 100 – 1000mbps
• Central device make it easy to manage the
network
• Cable breaks will not effect to the entire network
• Easy to expand
• Can connect more computers and devices

29. Physical Star Topology
Disadvantages
• Single point of failure type network
• The central device using is increases the cost
of the network

30. Extended Star Topology
Extended Star
Tree

31. Physical Mesh Topology
Each networking node are interconnected
with each other

32. Physical Mesh Topology
Characteristics
• It allowing most transmissions to be
distributed, even one of the connections goes
down
• Uses in the internet

33. Physical Mesh Topology
Advantages
• Can use for high traffic
• Cable breaks will not effect to the
communication
• Expansions and modifications can be done
without disrupting other devices

34. Physical Mesh Topology
Disadvantages
• Overall cost of the network is high
• Setup, maintaining and administrating this
network is very tough

35. Physical Hybrid Topology
The combination of more topologies is known
as hybrid topology

36. Physical Hybrid Topology
Advantages
• Flexible to expand and modify
• Very effective
Disadvantages
• Very complex
• Costly infrastructure

37. Logical Topologies
Logical topology represents the way that data
travel through the computer
Ex:
• Logical bus topology
• Logical ring topology
• Switching implemented as physical star

38. Logical Bus Topology
In here, the central device called hub works as
data packet distributer similar in action of the
bus topology
Hub

39. Logical Bus Topology
Characteristics
• Channel accessing method is CSMA/CD
• Cable using is twisted pair
• Connector using is RJ-45
• Data transfer speed is 10mbps
• Cable breaks will not effect to the entire
network
• Single point of failure type network

40. Logical Ring Topology
The central device called MSAU acts very
similar to the ring architecture when data
packets are travelling.
MSAU

41. Logical Ring Topology
Characteristics
• Channel accessing method is token passing
• Cable type is twisted pair
• Connectors are RJ-45
• Maximum data transferring speed is 16mbps
• Cable breaks will not affect to the entire network
• No collisions occurred
• Single point of failure type network

42. Switching implemented as physical star
The central device using is networking switch.
It receives data packets from end devices and
forwarding them towards the particular
destination device or computer.
Switch

43. Switching implemented as physical star
Characteristics
• Channel accessing method is switching
• Maximum data transferring speed is 1001000mbps
• Using twisted pair cables
• Using RJ-45 connectors
• Cable breaks will not effect to the whole network
• Single point of failure type network

44. Networking Cables
There are several kind of networking cables
• Coaxial Cables
• Twisted Pair Cables
• Fiber Optic Cables

45. Coaxial Cables
Coaxial cables are two types
• Thin net coaxial cables
• Thick net coaxial cables
Outer cover
Outer copper shield
Inner inductor
Inner insulator

46. Thin net coaxial cables
• Use to connect computers and devices in bus
topology and ring topology
• Well flexible
• Maximum segment length is 200m (185m)

47. Thick net coaxial cables
• Used as backbone cables and outdoor laying
• Not well flexible
• Maximum segment length is 500m (485m)

48. Coaxial cable connectors
BNC Connectors

49. Twister Pair Cables
• Most popular network cable in networking
• There are two types called:
1. Unshielded twisted pair cables
2. Shielded twisted pair cables
• Maximum segment length is 100m
• Data transferring speed varied on cable
categories

50. Unshielded Twister Pair Cables (UTP)

51. Shielded Twister Pair Cables (STP)

52. Twisted pair cable categories
Category
Speed
CAT 1
Voice grade
CAT 2
4 Mbps
CAT 3
16Mbps
CAT 4
100Mbps
CAT 5
1000Mbps
CAT 5e
1000Mbps
CAT 6
1000Mbps
CAT 7
1000Mbps

53. Twisted pair cable connectors
RJ-45 Connectors
RJ-45 Base

54. Twisted Pair / RJ-45 Cabling Types

55. Fiber Optic Cables
• Fiber optic cables uses light pulses to send and
receive data.
• Have very higher data transfer speed. Ex:
10Gbps or 100Gbps
• There are two types of fiber optic cables
mainly
– Single Mode Fiber (SMF)
– Multi Mode Fiber (MMF)

56. Single Mode Fiber Optic Cables
• Transmit one light pulse at a time for one
direction
• Because of this reason devices need two
cables for full duplex communication

57. Multi Mode Fiber Optic Cables
• Transmit more than one light pulse
• Because of that full duplex communication
can achieve using a single cable
• These cables are not suitable for long distance
data transfer

58. Undersea Cable Map

59. Fiber Optic Media Converters

60. Fiber Optic Connectors

61. Networking Devices
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NIC-Network interface card
Hub
Network Switch
Router
Bridge

62. Network Interface Card (NIC)

63. Network Interface Card (NIC)
• Every computer should have a network
interface card to connect to the network
• There are several things to consider before
buying a NIC
1. Network interface (connectors)
2. Internal interface (PCI, USB)
3. Network architecture

64. Hub

65. Hub
• Hub is use to connect all computers and other
devices together
• Hub is a broadcasting device
• Maximum data transfer speed is 10Mbps
• There are two types of hubs:
1. Active Hubs
2. Passive Hubs

66. Active Hubs
When active hubs receive a signal in one
port, it boost the signal and remove the
electromagnetic noises before send that to
other devices.

67. Passive Hubs
In passive hubs, it do not amplify the signal or
remove noise before send data to other
computers

68. Network Switch
Switches are also use to connect computers in
physical star topology and these devices are
intelligent than hubs.

69. How network switch works?
1. Switches maintain a small table in there RAM to
identify computers that related with the port
numbers.
2. When switch receives a data packet, it reads the
packet header to identify destination address.
3. After that it will search the entire table to find
the related port for that address.
4. Then it can directly forward that data packet to
the related computer rather than broadcasting.

70. Network Switch Types
• Layer 2 switches (unmanaged switches)
Using MAC addresses of connected devices.
• Layer 3 switches (managed switches)
Using IP addresses of connected devices.
Providing more features than layer 2 switches and
expensive.

71. Routers

72. Routers
• Routers are use to connect networks together.
• Routers are more intelligent devices and it use
IP addresses to deal with the packet.
• Routers are responsible for:
Identify proper networks and sub networks.
Forward data packets using the best path.
Destroying TTL data packets. Etc

73. Bridge
Bridge can use to connect different topologies
together or can use to connect different cable
types together.

74. IP Address (Internet Protocol)
• IP address is an unique address that use to
identify computers and devices.
• There are two IP versions called IPv4 and IPv6
• IPv4 is the common version that used in most
networks.
• IPv4 is made up with 4 decimal numbers and
each are separated by dots. (###.###.###.###)
and each number can be in between 0 to 255.
• IP versions, rules and regulations are created and
maintain by IANA (Internet Assigned Number
Authority)

75. IP Classes (IPv4)
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Class A
Class B
Can use in our networks
Class C
Class D (reserved for multicasting purposes)
Class E (reserved for experimental purposes)

76. IP Address
IP Addresses are made up with two sections
1. Network Address (network portion)
2. Host Address (host portion)
Class A
N
H
H
Class B
H
N
N
H
Class C
H
Class D
N
N
N
N
N
N
Class E
H
N
N
N
H
H

77. IP Ranges in each classes
IP Class
First Octate
Received Bits
IP Address
Range (min-max)
Class A
0#######
00000000-01111111
(1-126)
Class B
10######
Class C
1-126
0-255
0-255 0-255
10000000-10111111
(128-191)
128-191 0-255
0-255 0-255
110#####
11000000-11011111
(192-223)
192-223 0-255
0-255 0-255
Class D
1110####
11100000-11101111
(224-239)
224-239 0-255
0-255 0-255
Class E
1111#####
11110000-11111111
(240-255)
240-255 0-255
0-255 0-255

78. Activities
Assigning IP address to connect two
computers
Sharing Files
Sharing Printer

79. The End
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