This document provides an overview of computer networking concepts. It defines a network as connecting two or more computers to share resources. Networks allow simultaneous access to data, data sharing, personal communication, hardware sharing, and easier data backup. The main types of networks are LAN, MAN, and WAN. Network operating systems like peer-to-peer and client/server control software and hardware. Common network topologies include bus, star, tree, ring, and mesh. Wired and wireless media transmit data. Networking devices include network interface cards, repeaters, hubs, bridges, switches, and routers.

1. NetworkingBasics
Presented By:
Sahil Showkat
E-mail: sahil@pearlx.in
Website: www.pearlx.in

2. Network
 Group of two or more computers interconnected to share
resources, exchange data or allow electronic communication is
called as a network.
 The communication between two or more interconnected
devices is called networking.
 An internetwork is a connection of two or more networks.
 Internetworking means communication between different
networks.

3. The Uses of a Network
 Simultaneous access to data
 Data files are shared
 Access can be limited
 Shared files stored on a server
 Software can be shared

4. Sharing Data
File server contains documents
used by other computers.

5. The Uses of a Network
 Personal communication
 Email
 Instantaneous communication
 Conferencing
 Tele conferencing
 Videoconferencing
 Audio-conferencing
 Data-conferencing
 Voice over IP
 Phone communication over network wires

6. Voice Over IP

7. The Uses of a Network
 Easier data backup
 Backup copies data to removable media
 Server data backed up in one step

8. The Uses of a Network
 Hardware Sharing
 Printers, scanners and devices can be shared.

9. Types of Networks
 LAN
Local Area Networks are used to connect networking
devices that are in a very close geographic area such as a
floor of a building, a building itself or within a campus.
 MAN
Metropolitan Area Network are used to connect
networking devices that may span around the entire city.
 WAN
Wide Area Networks which connects two or more LANs
present at different geographical locations.

10. LAN
LANHUB
Administration

11. MAN
LANLAN
HUB SWITCH
MAN
CSE Administration

12. WAN
LANLAN
HUB SWITCH
CSE Administration
www.iustlive.com
WAN
Router Router

13. Network Operating System
 A network operating system is a software application that
provides a platform for both the functionality of an
individual computer and for multiple computers within an
interconnected network.
 A Network Operating System (NOS) is a software program
that controls other software and hardware running on a
network.
 It also allows multiple computers, known as network
computers, to communicate with one central hub and each
other to share resources, run applications, and send
messages.

14. Types of NOS’s
 There are two major types of network operating
systems:
 Peer-to-Peer
 Client/Server

15. Peer-to-Peer
 In Peer-to-Peer NOS, all
computers share
equivalent responsibility
for processing data. They
have same abilities to use
the resources available on
the network.
 They don’t have a
centralized management
source.

16. Advantages
 It is easy to install and so is the configuration of computers on
this network.
 All the resources and contents are shared by all the peers, unlike
server-client architecture where Server shares all the contents
and resources.
 P2P is more reliable as central dependency is eliminated. Failure
of one peer doesn’t affect the functioning of other peers.
 There is no need for full-time System Administrator. Every user
is the administrator of his machine. User can control their
shared resources.
 The over-all cost of building and maintaining this type of
network is comparatively very less.

17. Disadvantages
 In this network, the whole system is decentralized thus it is
difficult to administer.
 Security in this system is very less. Viruses, spywares,
trojans, etc malwares can easily transmitted over this P-2-P
architecture.
 Data recovery or backup is very difficult. Each computer
should have its own back-up system

18. Client/Server
 In Client Server NOS there is
one powerful computer
(known as server) which acts
as a provider of information
to other sub-ordinate
workstations (called client).
 Server becomes the heart of
the system, providing access
to resources and providing
security.

19. Advantages
 There is a centralized control. Servers help in
administering the whole set-up. Access rights and resource
allocation is done by Servers.
 All the files are stored at the same place. In this way,
management of files becomes easy. Also it becomes easier
to find files.
 As all the data is stored on server its easy to make a back-up
of it. Also, in case of some break-down if data is lost, it can
be recovered easily and efficiently.
 Rules defining security and access rights can be defined at
the time of set-up of server.

20. Disadvanatges
 Too many requests from the clients may lead to congestion,
which rarely takes place in P2P network. Overload can lead
to breaking-down of servers.
 If the server fails, the whole network goes down.
 It is very expensive to install and manage this type of
computing.

21. Topology
Topology is a physical layout of the systems connected in a
network.
 Different types of topology are:
 Bus
 Star
 Tree
 Choice affects
 Network performance
 Network size
 Network collision detection

22. Linear Bus Topology
 In bus topology all devices are connected to a single cable
or backbone.
 It supports half duplex communication.

23. Advantages
 Easy to setup.
 Requires less cable length.
Disadvantages
 A break at any point along the backbone will result in total
network failure.

24. Star Topology
 The most commonly used topology
 It consist of one centralized device which can be either a
switch or a hub.
 The devices connect to the various ports on the centralized
devices.
HUB/Switch

25. Advantages
 Easy to setup.
 Easy to add/remove parts
Disadvantages
 One hub crashing downs entire network.
 Uses lots of cable

26. Tree Topology
 A tree topology combines the characteristics of linear bus
and star topology.
 It consist of groups of star configured workstations
connected to a linear bus backbone cable.

27. Advantages
 Expansion of Network is possible and easy.
 We divide the whole network into segments (star
networks), which can be easily managed and maintained.
 Each segment is provided with dedicated point-to-point
wiring to the central hub.
 If one segment is damaged, other segments are not
affected.
Disadvantages
 Because of its basic structure, tree topology, relies heavily
on the main bus cable, if it breaks whole network is
crippled.
 More difficult to configure.

28. Ring Topology
 In ring topology each computer or device is connected to
its neighbor forming a loop.

29. Advantages
 Each computer has equal access to resources.
 There is no need for network server to control the
connectivity between workstations.
Disadvantages
 Failure of a single device or a break anywhere in the cable
causes the full network to stop communicating.
 Each packet of data must pass through all the computers
between source and destination. This makes it slower
than Star topology.
 If one workstation or port goes down, the entire network
gets affected.

30. Mesh Topology
 In mesh topology each device is directly connected to all other
devices.
 In fact a true mesh topology is the one where every node is
connected to every other node in the network. This type of
topology is very expensive as there are many redundant
connections

31. Advantages
 Data can be transmitted from different devices simultaneously.
This topology can withstand high traffic.
 Even if one of the components fails there is always an alternative
present. So data transfer doesn’t get affected.
 Expansion and modification in topology can be done without
disrupting other nodes.
Disadvantages
 There are high chances of redundancy in many of the network
connections.
 Overall cost of this network is way too high as compared to other
network topologies.
 Set-up and maintenance of this topology is very difficult. Even
administration of the network is tough.

32. Network Media
 Links that connect nodes.
 Communication channel through which data travels
on a network.
 Choice impacts
 Speed
 Security
 Size

33. Wire Based Media (guided)
 Twisted-pair cable
 Most common LAN
cable
 Four pairs of copper
cable twisted
 May be shielded from
interference
 Speeds range from
1 Mbps to 1,000 Mbps

34. Wire Based Media (guided)
 Coaxial cable
 Similar to cable TV wire
 One wire runs through cable
 Shielded from interference
 Speeds up to 10 Mbps

35. Wire Based Media (guided)
 Fiber-optic cable
 Data is transmitted with
light pulses
 Glass strand instead of
cable
 Immune to interference
 Very secure
 Hard to work with
 Speeds up to
100 Gbps

36. Wireless Media (unguided)
 Data transmitted through the air
 LANs use radio waves
 WANs use microwave signals
 Easy to setup
 Difficult to secure

37. Networking Devices
 Networking devices include all the equipment needed to
perform data-processing and communications within the
network.
 Network Interface Card
 Repeaters
 Concentrator/Hubs
 Bridges
 Switches
 Routers

38. Network Interface Card
 A NIC, typically an expansion card in a computer, is used to
connect a system to physical network media.
 Nowadays, computers are equipped with a built-in NIC.
 NICs are available for different types of network media, the
most common today being Ethernet NICs with a RJ-45
Socket for twisted pair cabling and wireless network
adapters with antenna.

39. Ethernet Card

40. LocalTalk Connectors

41. Token Ring Card

42. Repeater
 Repeaters clean, amplify, and resend signals that are
weakened by long cable length.
 Can be separate or built-in to hubs or switches
 Most economic way of expanding a network.
 The number of repeaters must be limited.
 Repeaters cannot connect different network
architecture.
 Repeater do not reduce network traffic.
 Half –Duplex Communication.

43. Hub/Concentrators
 Hubs regenerate and retime network signals.
 They are really multi-port repeaters.
 Hubs propagate signals through the network
 They cannot filter network traffic
 They cannot determine best path
 Uplink port – crossover mode or straight through mode

44. Functions of HUB
HUB
Data
DataDataDataData

45. Functions of HUB
HUB
Data
DataDataDataData
Data

46. Bridges
 Bridges are more intelligent than hubs.
 They increase network performance by segmenting
networks in separate collision domains.
 They maintains a table with MAC Addresses of all attached
nodes and on which segment they are located.
 Filter traffic by looking at the MAC address.
 Used for connecting two different topology (Segment).
 If the frame is addressed to a MAC address on the local side
of the bridge, it is not forwarded to the other segment
 Bridges maintain a MAC address table for both segments
they are connected to

47. Switches
 It is an Intelligent device.
 It maintains MAC address table (hardware address).
 Switches resemble bridges and can be considered as
multiport bridges.
 Each port of the switch has fixed bandwidth.
 Supports full duplex communication.

48. 1
2
3
4 5 6
7
8

49. Functions of Switch MAC ADDRESS TABLE
PORT MAC-
ADDRESS
1
2
3
4
5
6
7
8
001C-C01A-0002
001C-C01A-0004
001C-C01A-0002
1
2
3
4 5 6
7
8
S
D
DataDataDataDataDataData
Data
Source MAC
001C.C01A.0002
Destination MAC
001C.C01A.0004
DATA
Source MAC
001C.C01A.0002
Destination MAC
001C.C01A.0004
DATA

50. MAC ADDRESS TABLE
PORT MAC-
ADDRESS
Fa0/1
Fa0/2 001C-C01A-
0002
Fa0/3
Fa0/4
Fa0/5
Fa0/6
Fa0/7
Fa0/8
001C-C01A-0004
001C-C01A-0002
001C-C01A-0004
1
2
3
4 5 6
7
8
D
S Data

51. Types of Switches
 Unmanaged Switch
 Managed Switch
 Smart Switch
 Enterprise managed Switch

52. Router
 These are physical devices that join multiple wired and
wireless networks together.
 Routers select the best path to route a message, based
on destination address and origin.
 The router can direct traffic to prevent head-on
collisions.
 Routers know the addresses of computers, bridges and
other routers on the network.
 Routers usually uses the IP Addresses

53. End of Presentation