Networking Fundamental, types of Network

1. COMPUTER NETWORKS

2. Contents
 Definition and its components.
 Advantages and Disadvantages.
 Network Architecture.
 Switching Techniques.
 Types of Networks.

3. DEFINTION :
A computer network is defined as the interconnection of two
or more computers systems or peripheral devices ,to enable
the computers to communicate and share available
resources.
COMPONENTS:
 Two or more computers.
 Cables as links between the computers.
 A network interfacing card(NIC) on each computer.
 Connecting devices.
 Networking operating system
 A Protocol suite.

4. ADVANTAGESOFNETWORKING
 Sharing of hardware: like printers, fax etc.
 Sharing of software :installation and maintenance
becomes easy.
 Sharing file: increases productivity.
 Easy to take backup because data exist at one server.
 Cost effective method.
 Saves time.

5. DISADVANTAGES OF
NETWORKS
 High cost of installation.
 Requires time for administration.
 Failure of server may cause network breakdown.
 Cable faults may interrupt connectivity.
 Security from hackers should be monitored with
software programs like firewalls.
 Viruses can harm the network ,antivirus programs
should be used .

6. NETWORKARCHITECTURE
Network
Architecture
Peer to Peer
Network
Client-Server
Network

7. PEER TO PEER(P2P) NETWORK
 Computers connected with other computers to share
resources and accessing files.
 Computer is responsible for setting up and maintaining its
own security.
 Useful on a single LAN .
 It has no server.
 Less expensive.

8. CLIENT/SERVER NETWORK
 Server: A powerful central computer which has resources
and provide services.
 Server provide security and administration to the network.
 Client : Many computers running a program that requests the
service from a server.
 Local area network(LAN) is based on client server network
relationship.
 Front-end: software which user sees and interacts directly.
 Back-end :Interacts with shared resources such as
databases, printers or high power processors.

9. In large networks there are multiple paths linking the sender
and receiver. Selecting a path that data must take out of the
available options is switching.
SWITCHING TECHNIQUE
Switching
Techniques
Circuit
Switching
Message
Switching
Packet
Switching

10. Connects sender and receiver within an unbroken path.
A dedicated path exists between the two ends unless
communication is terminated.
Appropriate for immediate data transfer like telephone line.
CIRCUIT SWITCHING

11. Message is treated as independent unit and it is send
through series of nodes.
Each node receives the message stores it and then transmits
it also known as storage-and-forward network.
Channel efficiency is high .
Traffic congestion is reduced.
MESSAGE SWITCHING

12. Message is broken into a series of packets.
Each packet contains header contains information about
source ,destination and reassembling instruction.
Each packet takes different routes to reach destination.
Founds in large networks Like TCP/IP protocol uses it.
PACKET SWITCHING

13. TYPES OF NETWORKS
NETWORK
PAN LAN MAN WAN CAN

14. PERSONAL AREA NETWORK(PAN)
 Organized around an individual person.
 Communication capable devices like mobile computer, a cell
phone or personal digital assistant are connected.
 Wireless or cables.
 Range up to 10 meters.

15. LOCAL AREA NETWORK(LAN)
 Designed to operate over a small physical area like office,
factory or a building. It is usually a privately owned network.
 Easy to design and troubleshoot.
 Exchange of information and sharing of resources.
 Different types of topologies such as star, tree, bus, ring,
etc. can be used.

16. METROPOLITAN AREA NETWORK
(MAN)
 It covers the entire city & uses similar technology as LAN.
 It can be a single network such as cable TV network.
 It is a measure of connecting number of LAN’s on a large
network so that resources can be shared LAN to LAN as
well as device to device.

17. WIDE AREA NETWORK(WAN)
 When network spans over a large distance or at widely
separated locations .
 Connections through public networks like telephone lines,
leased telephone lines, satellite links and similar
channels done.
 Cheaper and more efficient.
 Used to transfer large blocks of data. INTERNET is the
largest WAN network in existence.

18. CAMPUS AREA NETWORK(CAN)
 The campus area network is interconnection of LAN with
limited geographical area.
 Network equipments such as switches, routers and the
transmission media i.e. optical fibre etc are almost entirely
owned by the campus owner.

19. PARAMETERS LAN MAN WAN
Ownership of network
Private Private orpublic Private orpublic
Geographical area
covered Small Moderate Very large
Designand
maintenance Easy Not easy Not easy
Communication medium
Coaxial cable
Coaxialcables, PSTN,
optical fiber
cables,wireless
PSTNor
satellite
links
Bandwidth Low Moderate High
Data rates(speed)
High Moderate Low
DIFFERENCE BETWEEN
LAN, WAN, MAN.

20.  OSI stands for Open Systems Interconnection.
 It has been developed by ISO – ‘International
Organization of Standardization‘, in the year 1974.
 It is a 7 layer architecture with each layer having
specific functionality to performed.
 All these 7 layers work collaboratively to transmit the
data from one device to another across the globe.
THE OSI MODEL
2.20

21. In 1978, the International Standars
Organization (ISO) began to develop its OSI
framework architecture.
OSI has two major components: an abstract
model of networking, called the Basic
Reference Model or seven-layer model, and
a set of specific protocols.
OSI History
21

22. The concept of a 7 layer model was provided
by the work of Charles Bachman.
 Various aspects of OSI design evolved from
experiences with the Advanced Research
Projects Agency Network (ARPANET) and the
fledgling Internet.
OSI History
22

23. 2.
Seven layers of the OSI model

24. Interaction between layers in the OSI model

25. An exchange using the OSI model

26. The lowest layer of the OSI reference model is the
physical layer.
 It is responsible for the actual physical connection
between the devices.
 The physical layer contains information in the form of
bits.
 When receiving data, this layer will get the signal
received and convert it into 0s and 1s and send them
to the Data Link layer, which will put the frame back
together.
The Physical Layer
2.26

27. Physical layer
The physical layer is responsible for movements of
individual bits from one hop (node) to the next.

28. The functions of the physical layer are :
Bit synchronization: The physical layer provides the
synchronization of the bits by providing a clock. This
clock controls both sender and receiver thus providing
synchronization at bit level.
Bit rate control: The Physical layer also defines the
transmission rate i.e. the number of bits sent per
second.
The Physical Layer’s Functions
2.28

29. Physical topologies: Physical layer specifies the way in
which the different, devices/nodes are arranged in a
network i.e. bus, star or mesh topology.
Transmission mode: Physical layer also defines the way
in which the data flows between the two connected
devices: Simplex, half-duplex and full-duplex.
The Physical Layer’s Functions

30. The data link layer is responsible for the node to node
delivery of the message.
The main function of this layer is to make sure data
transfer is error free from one node to another, over
the physical layer.
When a packet arrives in a network, it is the
responsibility of DLL to transmit it to the Host using its
MAC address.
The Data Link Layer

31. 2.31
Data link layer
The data link layer is responsible for moving
frames from one hop (node) to the next.

32. The functions of the data Link layer are :
Framing: providing a way for a sender to transmit a
set of bits that are meaningful to the receiver. This
can be accomplished by attaching special bit patterns
to the beginning and end of the frame.
Physical addressing: After creating frames, Data link
layer adds physical addresses (MAC address) of
sender and/or receiver in the header of each frame.
The Data Link Layer ‘s
Functions
2.32

33. Error control: providing a mechanism of error control
in which it detects and retransmits damaged or lost
frames.
Flow Control: flow control coordinates that amount of
data that can be sent before receiving
acknowledgement.
Access control: When a single communication
channel is shared by multiple devices, data link layer
helps to determine which device has control over the
channel at a given time.
The Data Link Layer ‘s Functions
2.33

34. The network layer is responsible for the source- to-
destination delivery of packet, possibly across multiple
networks(links).
It also takes care of packet routing i.e. selection of
shortest path to transmit the packet, from the number
of routes available.
The sender & receiver’s IP address are placed in the
header by network layer.
The Network Layer
2.34

35. Network layer
The network layer is responsible for the
delivery of individual packets from
the source host to the destination host.

36. The functions of the Network layer are :
Routing: determining which route is suitable from
source to destination..
Logical Addressing: In order to identify each device on
internetwork uniquely, network layer defines an
addressing scheme. The sender & receiver’s IP address
are placed in the header by network layer. Such an
address distinguishes each device uniquely and
universally.
The Network Layer ‘s Functions
2.36

37. Transport layer is responsible for process-to-process
delivery of the entire message
The data in the transport layer is referred to as
Segments.
The Transport Layer

38. The functions of the transport layer are :
Segmentation and Reassembly: This layer accepts the
message from the (session) layer , breaks the message
into smaller units . Each of the segment produced has a
header associated with it. At the destination station it
reassembles the message.
Service Point Addressing: In order to deliver the
message to correct process, transport layer header
includes a type of address called service point address or
port address. Thus by specifying this address, transport
layer makes sure that the message is delivered to the
correct process.
The Transport Layer ‘s Functions

39. This layer is responsible for establishment of
connection, maintenance of sessions, authentication
and also ensures security.
The Session Layer

40. The functions of the session layer are :
Session establishment, maintenance and termination:
The layer allows the two processes to establish, use
and terminate a connection.
Synchronization : This layer allows a process to add
checkpoints which are considered as synchronization
points into the data.
Dialog Controller : The session layer determines which
device will communicate first and the amount of data
that will be sent.
The Session Layer ‘s Functions
2.40

41. The presentation layer is responsible for translation,
compression, and encryption.
The Presentation Layer
2.

42. The application layer enable the user to access the
network.
These applications produce the data, which has to be
transferred over the network.
This layer also serves as window for the application
services to access the network and for displaying the
received information to the user.
The Application Layer
2.

43. Summary of layers

44. Contents
 Server
 Typesof servers.
 NetworkTopologies.

45. SERVERS
 A powerful specialized computer that facilities the sharing of
data, software and hardware resources e.g. printers, modems
etc. on the network are termed as servers.
 Server provides recourses to the client when request is
generated.
 Combination of one or more powerful processors.
 Easy to maintain security by granting limited accessing
permissions.

46. TYPES OF SERVERS

47.  File server: It provide the services for storing,
retrieving and moving the data. A user can read,
write, exchange and manage the files with the help
of it.
 Printer server: It is used for controlling and managing
printing and fax service on the network.
 Application server: It helps in sharing expensive software
and additional computing power in a network.
 Message server: It is used to co-ordinate the interaction
between users, documents and applications. The data can
be used in the form of audio, video, binary, text or graphics.
 Database server: It is a type of application server. It allows
the user to access the centralised strong database.
TYPES OF
SERVERS

48. Topology defines the geographical ,physical, or logical
arrangement of computer networking devices.
NETWORK TOPOLOGY
NETWORK TOPOLOGY
BUS STAR RING MESH TREE HYBRID

49. BUS TOPOLOGY
 All computers and devices
connected to central cable
or bus.
 Consists of a main run
of cable with a
terminator at each end.
 Popular on LANs
because they are
inexpensive and easy
to install.

50. STAR TOPOLOGY
 All devices connect to a
central device, called hub.
 All data transferred from
one computer to another
passes through hub.
 Easy to add new terminal.

51. RING TOPOLOGY
 Cable forms closed ring or loop,
with all computers and devices
arranged along ring.
 Data travels from device to
device around entire ring, in
one direction.
 Primarily is used for LANs,
but also is used in WANs.

52. MESH TOPOLOGY
 Each computer and device are
connected with each other by
separate cable.
 Topology can handle a large
volume of traffic.
 Used in Wireless networks.
 If one cable fail data always
has alternative path to get to its
destination.

53. TREE TOPOLOGY
 It is a network setup consists of a
group of star-figured workstations
connected to a linear bus
backbone cable.
 Failure of cable cause lose to the
sub-network only other rest of the
network works normally.
 Expansion of network is easy but
maintenance is difficult.

54. HYBRID TOPOLOGY
 It is combination of two or
more networks topologies.
 Individual networks could be
star , bus, ring or even mesh
but star and ring topologies are
used mostly.
 Existing networks can be
connected with required
hardware.
 Easy to implement, maintain
as well scale up.

55. TRANSMISSION MEDIA
PART -1
GUIDED/WIRED MEDIA

56. Transmission Media
 In communication process
transmission media is a pathway that
carries the information from sender
to receiver end.
 Different types of cables or waves
are used to transmit data.
 Data is transmitted normally through
electrical or electromagnetic signals.

57. Description
 Transmission media are located
below the physical layer of the
transmission protocol.
 Computers use signals to represent
data.
 Signals are transmitted in form of
electromagnetic energy.

58. Classification

59. NETWORK
DEVICES

60. Networking Devices
MAC address
IP address
NETWORKING DEVICES:
Hub
Switch
Router
Content
Modem
Repeater
Bridge
Gateways

61.  NETWORK DEVICES: Devices that help the network or
nodes to be linked to each other, with the objective of
sharing data and/or hardwares or software.
 INTERNETWORK DEVICES: When two or more networks or
subnets are to be connected to each other for
communication between hosts on different types of network
such devices are used.
INTRODUCTION

62. A network interface card (NIC)is that is
attached to each computer on the network.
The NIC manufacturer assigns a unique
physical address to each NIC card this address
is called as Media Access Control Address(MAC
address).
It consist of 6 bytes each byte is separated by ’:
‘, first three bytes are manufacturer-id and last
three bytes are the card number assigned by
manufacturer to each card.
MAC Address

63. Every network follow some rule for
communication, such set of rules are
called PROTOCOLS.
Common protocol and used by internet
is Transmission control
protocol/Internet protocol(TCP/IP).
Each computer on a TCP/IP network
has a unique identification number
called IP address. Its older version is 32
bit long (IPv4 address) and newer
version is 128 bit(IPv6 address).
IP Address

64. Connects two or more devices
without having to connect to each
other directly.
Uses twisted pair cables.
Forward the data it received from a
connected device to all other
connected devices.
It is also known as Dumb Switch.
It is cheaper than the switch.
Hub

65. Active Hub: This hub monitors, amplifies, and regenerates signal.
Signals are strength in active hub.
Passive Hub: This hub provides only physical connection points for
computer devices, it does not take an active role in the network.
Intelligent Hub: Provides additional feature to the active hub here
all the ports of the hub can be monitored , configured, enable or
disable.
Types of Hub

66. It connects different computer and sub-
networks to one network.
It transfers data to the specific computer
using packet switching technique.
It uses MAC address of the destination
computer to deliver packet on the
network.
Switch

67.  It is used to connect multiple networks
irrespective of their protocol.
 It handles data packets with their IP
address.
 It identifies the destination with the
packet header and using best route ,the
message is forwarded to the next device in
the network.
Routers
ROUTER

68. Broadband Routers: It is used to connect computers or to internet. To
connect internet through phone and Voice over IP technology (VOIP), we
need broadband routers.
Wireless Routers: They create wireless signals in our home and office, so
any pc in the range can be connected through the network and can use
internet.
Edge Routers: It is placed at the border of ISP network to connect
various BGP(Border gateway Protocol).
Core Router: It is used as backbone of LAN network spread in large area.
Types of Routers

69.  It is a device used to connect and communicate with other computers via
phone line.
 Modulation/Demodulation: process of sending data on a wave(analog) is
modulation. (Conversion of digital signal into analog signal) and vice versa.
 Two types of modems are : Internal modem(Fix inside the CPU ),
External modem(Connected externally to the
computer).
Modem

70. Repeater
 A repeater is a network device that
amplifies and restores signals for long-
distance transmission.
 Repeater ensures the delivery of the
packet over the chances of weak signals.
 Two types of Repeater:
 Amplifier (amplifies all incoming
signals both signals and noise),
 Signal Repeaters (collects the
inbound packet and retransmit the
packet as it was with source).

71. Bridge
 A bridge is a network device that
establishes intelligent connection
between two local network with the
same standard but with different types
of cables.
 The bridge examines the physical
destination address of the packet ,and
decides the whether the packet should
cross the bridge or not.

72.  Local bridge: Connects network
segments of the same type and at the
same location.
Translation bridge: Connects
network segments at the same
location that use different media or
different protocol.
Remote bridge: Connects network
segment at remote locations, using a
wide area network (WAN) link.
Types of Bridges
Types of Bridges

73. It is a device that connects at the highest level
of network and used to connect dissimilar
networks.
A gateway converts Ethernet traffic from the
LAN to SNA(System Network Architecture)i.e.
networking standard developed by IBM, for
mainframe and minicomputers.
It is a node which serves as an entrance to
another network.
It acts as a proxy server(a machine that is not
a server but appears as a server) and a
firewall(a system designed to prevent
unauthorized access to or from a private
network).
Gateways

79. FDDI: Fiber Distributed Data
Interface