What is Computer Networks Types of computer networks Advantages of Computer Networks Computer networks architecture Networks software Reference model

1. Computer Networks
Prepared By
P.SUDARMANI,M.SC.M.PHIL.,
ASSISTANT PROFESSOR IN COMPUTER SCIENCE
P.Sudarmani,M.sc,M.Phil.,Assistant Professor 04/08/2020

2. P. Sudarmani, M.Sc,M.phil., Assistant Professor 09/07/2020

3. Introduction
 Computer network:
A computer network is a collection of
computers and devices
connected together via
communication devices and
transmission media.
Devices- printers,
scanner
Communication devices
NIC
HUB
Router
Transmission media
Physical
Infrared
Radio wave
Satellite
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

4. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

5. Internet
Workstation
Cable modem Router
server
switch
printer
Print server
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

6. Advantages of Computer Networks:
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

7. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

8. LAN
Types of computer
Network
Computer Network
MAN WAN
Network Architecture
Network topologies
Network
Communication
technologies
Star
Peer to Peer
Client/Server
Ring Bus
Intranet
Ethernet Internet
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

9. There are two types of transmission technology:
1. Broadcast Networks
➢This has a single communication channel that is shared by
all the machines on the network.
➢The data transmitted is converted in small packets form.
Each packet contains address field of the destination station.
➢Ex:- a person standing at corridor “watson, come here. I
want you”
➢sending same packets to all the stations within a network
is called as broadcasting.
➢When data packets are sent to a specific group of stations it
is called as multicasting. This is a selective process
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

10. 2. Point-to-point Network
Point-to-point connections use an actual length of wire or
cable to connect the two ends, but other options, such as
microwave or satellite links, are also possible. When you change
television channels by infrared remote control, you are establishing a
point-to- point connection between the remote control and the
television's control system.
This network provides a dedicated link between any two
stations . Such a transmission is called unicasting.
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

11. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

12. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

13. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

14. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

15. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

16. Home Network Applications
1. Access to remote information
• Many people pay their bills, manage bank accounts, handle their investments
electronically.
• Home shopping.
• On-line newspaper which can be personalized.
• Access to information system like world wide web, which contains information
about
arts,business,cooking,government,health,history,science,sports,travel,……..
• All the above applications involve in interactions between a person and remote
database.
2. Person-to-person communication
• Electronic mail or email which allow users to communicate with no delay
• Videoconference- which makes possible
3. Interactive entertainment
Huge and growing industry,Video,Game playing
4. Electronic commerce
Electronic Commerce, commonly known as E- commerce or ecommerce, is trading
in products or services using computer networks, such as the Internet E-commerce
facilitates home shopping, catalogue of company products.
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

17. Wireless
Wireless networks are computer networks that are not
connected by cables of any kind. The use of a wireless network
enables enterprises to avoid the costly process of introducing cables
into buildings or as a connection between different equipment
locations. The basis of wireless systems are radio waves, an
implementation that takes place at the physical level of network
structure.
P.Sudarmani,M.Sc,M.Phil.,Assistant
Professor 09/07/2020
Wireless networks use radio waves to connect devices such
as laptops to the Internet, the business network and applications.
When laptops are connected to Wi-Fi hot spots in public places, the
connection is established to that business’s wireless network.

18. On a network built using the client-server architecture, the devices
communicate to other devices through a central computer referred to as a
server.
The server is a terminal with high processing power, which provides
services for the other computers on the network.
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

19. On a network built using the peer-to-peer architecture, no
specific distinction exists between a client and a server.
Any node can provide a service as well as send a request for a
service from another node on the network.
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

20. NetworkSoftware
The first computer designed with the hardware as the
major concern and the software as an afterthought. This no
longer works. Network software is now highly structured.
• Protocol Hierarchies
• Design Issues for the Layers
• Connection-Oriented and Connectionless Services
• Service Primitives
• The Relationship of Services to Protocols
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

21. Reference Models
• The OSI Reference Model
• The TCP/IP Reference Model
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

22. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

23. THE SEVEN OSI REFERENCE MODEL
LAYERS
P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020

24. P.Sudarmani,M.sc,M.Phil., Assistant Professor 09/07/2020