Basics of Networking by Akash Singh Third Year Diploma in Computer Engineering.

1. NETWORK
BY – AKASH SINGH

2. WHAT IS A NETWORK ?
• Network, in computer science, a group of computers and associated
devices that are connected by communications facilities.
• Network is an inter connected collection of autonomous computers.
• When two or more computers are joined together so that they are
capable of exchanging information , they form a network.

3. NEED OF NETWORKING ?
• Resource sharing - Through a network , data , s/w and h/w
resources can be shared irrespective of the physical location of the
resources and the user.
• Reliability – A file can have its copies on two or more computers of
the network.
• Reduced Cost – Sharing resources reduces the cost
• Fast Communication – Information can be exchanged at a very fast
speed.

4. WHAT IS INTERNET ?
Internet is worldwide network of computer networks.
How does it work ?
• Most computers are not connected directly to the internet .
• They are connected to smaller networks .
• Which are connected through gateways to the internet
backbone .

5. WHAT IS A GATEWAY ?
• Gateway is a device that connects
dissimilar networks.
• A backbone is a central interconnecting
structure that connects one or more
networks just like the trunk of a tree.

6. FEW THINGS RELATED TO NETWORK
• Workstation or Nodes : refers
to a computer that are attached
to a network .
• Server or Hub : The master
comp is called server, it facilitates
the sharing of data .

7. WHAT IS NETWORK INTERFACE UNIT (NIU) ?
• It is a device attached to each workstation and server.
• Helps to make connections within the network.
• Each NIU has a unique no identifying it called node address.
• NIU is also called terminal access point (TAP).
• Also called Network Interface Card (NIC).
• Each NIC is given a unique physical address called MAC
address.

8. HOW DATA IS TRANSMITTED ACROSS NETWORKS ?
Switching Techniques are used for transmitting data across networks.
3 types of switching techniques are there.
• Circuit Switching ,
• Message Switching ,
• Packet Switching .

9. TYPES OF NETWORKS
• Local Area Network - LAN
• Metropolitan Area Network – MAN
• Wide Area Network – WAN
• Personal Area Network - PAN
• Campus Area Network - CAN

10. TOPOLOGIES
The pattern of interconnection of nodes in a network is called the topology.
Types of TOPOLOGIES :-
•Bus Topology,
•Star Topology,
•Ring Topology,
•Tree Topology,
•Mesh Topology.

11. NETWORK DEVICE
•Modem ,
•RJ 45 Connector,
•Ethernet Card,
•Hub,
•Switch,
•Repeater,
•Bridge,
•Router.

12. TYPES OF NETWORK
Two classifications are
• Peer-to-Peer network :- * Nodes provide and request services *
User in each node administers resources * No extra investment *
Easy to setup * Very weak security * Additional load on nodes .
• Server based network :- * Designated computer to administer *
Resources centralized * Supports larger networks * Strong security *
Expensive .

13. OSI MODEL
OSI Reference Model
• Open Systems Interconnection
• No one really uses this in the real world.
• A reference model so others can develop
detailed interfaces .
• Value: The reference model defines 7 layers of
functions that take place at each end of
communication and with each layer adding its
own set of special related functions .
• Flow of data through each layer at one time.

14. NETWORK PROTOCOLS
• Protocol are used for communication between computers in different computer
networks. Protocol achieves : * What is communicated between computers? * How
it is communicated? * When it is communicated? * What conformance (bit
sequence) between computers?
• Key elements of a protocol are:
* SYNTAC: Data format and signal levels ,
* SEMANTICS: Control information for coordination and error handling , * TIMING:
Synchronization, speed matching, and sequencing .
• Examples of protocols: * WAN Protocol: TCP/IP .

15. THANK YOU