This document provides an overview of computer networks, including their components, topology types, network types, the OSI model layers, TCP/IP protocol suite, connecting devices, applications, and conclusions. It defines what a network is, describes common network components like nodes and transmission medium. It explains physical topologies like bus, star, and ring, and network types like LAN, MAN, and WAN. It outlines the seven layers of the OSI model and describes the functions of the physical, data link, network, transport, and upper layers. It provides examples of network applications and concludes with references for additional reading.

1. by
P.PRABAKARA PANDIAN
A.SURIYA MANIRAJ

2. INTRODUCTION
ABOUT NETWORK
COMPONENTS
PHYSICAL TOPOLOGY AND ITS TYPES
TYPES OF NETWORK
LAYERS IN OSI MODEL
TCP/IP PROTOCOL SUITE
CONNECTING DEVICES
APPLICATIONS
CONCLUSION
REFERENCES

3. A network is a combination of hardware and software
that sends data from one location to another.
Two or more computers that are interconnected so
they can exchange data, information & resources.
A networked connection allows computer to
communicate with other devices.

4. A network is a set of devices (often referred to as
nodes) connected by communication links.
A node can be a computer, printer, or any other
device capable of sending and/or receiving data
generated by other nodes on the network.

5. Message
Sender
Receiver
Transmission medium
Protocol

7. every device has a
dedicated point-to-point
link to every other device.
Need n(n - 1) physical
links.
Need n(n -1) /2 physical
links.

8. Better privacy and security
More robust
•Installation is difficult
•Reconfiguration is difficult

10. Each device needs only one link and one I/O port.
Installation and reconfiguration is easy
If the central hub fails, the whole network fails.

12. Installation is easy
Require less cable and I/O port
•If the backbone fails, the whole network fails.
•Reconfiguration is difficult.

14. Fault identification is easy
Every node is given equal access to the token
•Adding or removing nodes disturb the network
•Failure of node in a ring can affect the entire network.

17. A local area network (LAN) is usually privately owned
and links the devices in a single office, building, or
campus.
Speeds are normally 100 or 1000 Mbps.
LAN topologies are bus, ring, and star.
LAN size is limited to a few kilometers.

18. A wide area network (WAN) provides long-distance
transmission of data, image, audio, and video
information over large geographic areas that may
comprise a country, a continent, or even the whole
world.
A WAN can be as dial-up line that connects a home
computer to the Internet.

20. MAN means metropolitan area network.
A metropolitan area network (MAN) is a network
with a size between a LAN and a WAN.
It normally covers the area inside a town or a city.

22. Open Systems Interconnection
Standard Model for Data Communications
Specified by International Standards Organization
(ISO)
Adopted by CCITT/ITU
Official Model Explained in X.200 Series

23. The physical layer coordinates the functions required
to carry a bit stream over a physical medium.
The physical layer is responsible for movements of
individual bits from one hop (node) to the next.

24. Physical characteristics of interfaces and medium
Representation of bits
Data rate
Synchronization of bits
Line configuration
Physical topology
Transmission mode
Begin EndData
Link Layer

25. Data Link layer adds header and trailer to the data
received from the higher layer.
It transports the data as Frame.
This layer is responsible for the delivery of frames
from node to node.

26. Framing
Physical addressing
Flow control
Error control
Access control
LL Hdr Data
Network Layer

27. Network layer adds header to the data received from
the higher layer.
It transports the data as Packets.
This layer is responsible for the delivery of packets
from source host to destination host.

28. Logical addressing
Routing
Net Hdr Data
Transport Layer

29. Transport layer adds header to the data received from
the higher layer.
It transports the data as segments.
This layer is responsible for the delivery of segments
from one process to another process.

30. Service-point addressing
Segmentation and reassembly
Connection control
Flow control
Error control
Trans Hdr Data
Upper Layers

31. The session layer is responsible for dialog control and
synchronization.
Session layer is also responsible for terminating the
connection.
Characteristics
Dialog control
Synchronization

32. The presentation layer is responsible for translation,
encryption and compression.
Presentation layer defines the format in which the
data is to be exchanged between the two
communicating entities.
Characteristics
Translation
Encryption
Compression

33. The application layer is responsible for providing services
to the user.
Application layer interacts with application programs and
is the highest level of OSI model.
Examples of application layer are applications such as file
transfer, electronic mail, remote login etc.
Characteristics
Network virtual terminal
File transfer, access, and management
Mail services
Directory services

36. Data sharing
Instant And Multiple Accesses
Video Conferencing
Internet Service
Broad Casting
Remote Access And Login
Saves Cost

37. The development of the personal computer brought
about tremendous changes for business, industry,
science, and education.
A similar revolution is occurring in data
communications and networking.
Technological advances are making it possible for
communications links to carry more and faster
signals. As a result, services are evolving to allow use
of this expanded capacity.

38. Data communication and networking by Behrouz A.
Forouzan
Data and computer communication by William
Stallings
Computer Networks by Larry L. Peterson and Bruce S.
Davie
Computer networks by Andrew S. Tanenbaum
Computer Networking by James F. Kuruse, keith W.
Ross.