For script: https://docs.google.com/document/d/1g4ehLb3L1lMvATYZTh-3TERefBO3gP4MeNRYhU9j39c/edit?usp=sharing

1. Click to edit Master title style
1
APPLICATION LAYER
PARADIGMS
COMPUTER NETWORKS

2. Click to edit Master title style
2
INTRODUCTION
● The application layer provides services to the user.
● To use internet , need two application programs to interact with each other:
• One running on a computer somewhere in world
• Another running on a computer somewhere else
● Need to send messages to each other through internet infrastructure.

3. Click to edit Master title style
3
PARADIGMS

4. Click to edit Master title style
4
CLIENT-SERVER PARADIGM
A distributed application model based on resource or services called servers and service requesters
as clients.
Communication at the application layer is between two running application programs called processes :
1. Client - It is a running program that initializes
the communication by sending request.
2. Server - It is program that waits for the
request from a clients.

5. Click to edit Master title style
5
CLIENT-SERVER PARADIGM
Server:
– always-on host
– permanent IP address
– server farms for scaling
Clients:
– communicate with server
– may be intermittently connected
– may have dynamic IP addresses
– do not communicate directly with each
other

6. Click to edit Master title style
6
CLIENT-SERVER PARADIGM
HOW IT WORKS ?
• Client requesting something and the
Server serving it as long as it's present in
the database.
• It is done based on the centralized
structure
• Few steps to follow to interacts with the
servers a client.

7. Click to edit Master title style
7
CLIENT-SERVER PARADIGM
ADVANTAGES:
1. Centralised system
2. Less cost effective
3. Separable Capacity
DISADVANTAGES
1. Clients are prone to viruses
2. Servers are prone to DOS
3. Data packets may be spoofed

8. Click to edit Master title style
8
PEER-TO-PEER PARADIGM
● There is no need for a server process to be running all the time and waiting for the client
processes to connect.
● The responsibility is shared between peers.
● A P2P system is a distributed collection of peer nodes.
● Each node is a both a server and client:
• May provide services to each peers.
• May consume services from other peers.

9. Click to edit Master title style
9
PEER-TO-PEER PARADIGM
– No always-on server
– Arbitrary end systems directly
communicate
– Peers are intermittently connected
and change IP addresses
– Pair of hosts called peers.
– Peers communicate without
passing through some special server.
– Highly scalable but difficult to
manage.

10. Click to edit Master title style
10
PEER-TO-PEER PARADIGM
HOW IT WORKS ?
• A peer-to-peer network allows
computer hardware and software to
communicate without the need for a
server.
• One peer makes a request, it is
possible that multiple peers have the
copy of that requested object.
• The file transfer takes place directly
between peers.

11. Click to edit Master title style
11
PEER TO PEER PARADIGM
ADVANTAGES:
1. Easy to scale
2. Easy to set up and maintain
3. Reduces technical Staff
DISADVANTAGES
1. Not very secure
2. Hard to backup
3. Performance issues

12. Click to edit Master title style
12
PEER-TO-PEER PARADIGM
Examples:
• Distributed downloads in Ubuntu,
Linux Mint OS
• Networking between 2 computers in
windows OS
Uses:
● Resource sharing and
collaborative working

13. Click to edit Master title style
13
CONCLUSION APPLICATION PARADIGMS
CLIENT SERVER
A distributed application model based on resource or
services called servers and service requesters as
clients
PEER TO PEER
A distributed application model that partitions tasks or
workloads between peers

14. Click to edit Master title style
14
THANK YOU