1. Networking Concepts
S. Sethuraman, I B.C.A.

2. Network?
 Interconnected Collection of
autonomous Computers.
 Two computers are Interconnected If
they are capable of exchanging
information.
 Computers on network can start,
stop,or control another.

3. Need for Networking
 Resource Sharing
 Reliability
 Cost Factor
 Communication Medium

4.  Application of Networks
 Sharing
 Access to remote data base
 Communication Facilities

5. Evolution of Networking
 ARPANET (Advanced Research Project
Agency NETwork)
 It connected computers at different
Universities and U.S. Defense.
 Another Federal Agency, the National
Science Foundation, created a new, high-
capacity network called NSFnet.
 NSFnet, more capable than ARPANET.

6. The Internet
 The Internet is a world wide network of
computer networks.
 Gateways and Backbone.

7.  Gateway
It is a device that connects dissimilar
networks.
 Backbone
It is central interconnecting structure that
connects one or more networks just like
spine of a human being.

8. Internet Functioning
 TCP/IP
 Transmission Control Protocol is
responsible for dividing and reassembling
message/file into packets on the source
computer.
 Internet Protocol is responsible for
handling the address of destination
computer so that each packet is routed
(sent) to its proper destination.

9. Server
 A computer that facilitates the sharing
of data, software, and hardware
resources on the network, is termed
as a server.
 Types:
(i) Non-Dedicated Server
(ii) Dedicated Server

10. Switching Techniques
 Switching techniques are used for
transmitting data across networks.
 Types:
(i) Circuit Switching
(ii) Message Switching
(iii) Packet Switching

11. Transmission Media
 Connecting Media or Connecting
Cables.
 Types:
 Twisted Pair Cable
 Co-axial Cable
 Optical Fibres

12. Type Sub Type
Maximum Segment
Length Bandwidth Installation cost Interference
Twisted Pair
Cable UTP 100 mts 100 mbps easy cheapest high
STP 100 mts 500 mbps moderate moderate moderate
Coaxial Cable Thinnet 185 mts 10 mbps easy cheapest moderate
Thicknet 500 mts 10 mbps hard moderate low
Fibre Optic
Cable Multinode 2 kms 100 mbps very hard expensive none
Singlenode 100 kms 2 gbps very hard expensive none

13. Types of NETWORKS
 Local Area Network (LAN)
 Diameter of network not more than a few
kilometer.
 Metropolitan Area Network (MAN)
 Diameter of network of about 100
kilometers.
 Wide Area Network (WAN)
 Diameter of network more than 100’s of
kilometers.

14. Network Topologies
 Pattern of interconnection of nodes in
a network is called the topology.
 Types:
 Star
 Bus
 Ring
 Tree
 Graph
 Mesh

15. Modem
 A computer peripheral that allows you
to connect and communicate with
other computers via telephone lines.
 Syncing Carrier wave with modulating
wave.
 Modulation and Demodulation
 Modulation types:
 AM (Amplitude modulation)
 FM (Frequency modulation)
 PM (Phase modulation)

16.  Amplitude Modulation
 Frequency Modulation

17.  Phase Modulation

18. Demodulation
 Demodulation Circuit

19. Increasing Internet Speed
 Gauss Theorem states that “Surface
integral of electric field over a closed
surface is 1/ξ˳ times the charge
enclosed by it.”
 For a cylindrical surface:

20.  i.e.,
 ∫E.dS=q/ξ˳
 As Information (I) is the charge per unit length
and length of he wire is H, charge enclosed by
suface is:-
 ∫E.dS=IH/ξ˳
 E(2ΠRH) (cos 0˚)=IH/ξ˳
 I=Eξ˳(2ΠR)
 I is directly proportional to R, that is, double
the radius of the wire double the information
passed and so on.