Shivangi submitted a topic paper on "Computer Networking" for her Computer Science and Engineering department. The 3-page paper discusses the objectives of networking, including enabling communication between applications on different computers and matching application requirements. It also covers the four steps of networking, including interconnecting multiple links, finding and routing data, and matching applications needs. Additionally, it defines key networking concepts like links, nodes, packet and circuit switching, congestion control, the layered Internet protocol stack, and considerations for security in computer networks.

1. NAME:-SHIVANGI
DEPT:- COMPUTER SCIENCE & ENGINEERING
ROLL NO:- ‘9’
GROUP:- ”X”
TOPIC NAME:- “Computer
Networking”
SUBMITTED TO:-

2. Communication between applications on
different computers.
Must understand application needs/demands.
Traffic data rate.
Traffic pattern (bursty or constant bit rate).
Traffic target (multipoint or single destination,
mobile or fixed).
Delay sensitivity.
Loss sensitivity.
What is the Objective of
Networking

3. Four Steps to Networking
Communicating across a link.
Connecting together multiple links
(internetworking).
Finding and routing data to nodes on
internetwork.
Matching application requirements.

4. A First Step
Creating a link between nodes.
Link: path followed by bits.
•Wired or wireless.
•Broadcast or point-to-point (or
both).
Node: any device connected to a
link.

5. 5
Types of Links
Point-to-Point Multiple Access
…

6. 6
Switched Network
What are Switched Networks
 Switch: moves bits
between links
 Packet switching
 Circuit switching

7. 7
Packet Switching (Internet)
Packets

8. 8
Packet Switching
 Interleave packets from different sources.
 Efficient: resources used on demand.
 Statistical multiplexing
 General
 Multiple types of applications.
 Accommodates bursty traffic.
 Addition of queues.

9. 1-9
Circuit Switching: FDM and TDM
FDM
frequency
time
TDM
frequency
time
4 users
Example:

10. 10
What if Network is Overloaded
Problem: Network Overload
 Short bursts: buffer
 What if buffer overflows?
 Packets dropped
 Sender adjusts rate until load = resources
 Called “congestion control”
Solution: Buffering and Congestion Control

11. 1-11
Why layering
Dealing with complex systems:
 explicit structure allows identification, relationship of
complex system’s pieces
 layered reference model for discussion
 modularization eases maintenance, updating of
system
 change of implementation of layer’s service
transparent to rest of system
 e.g., change in gate procedure doesn’t affect
rest of system
 layering considered harmful

12. 1-12
Internet protocol stack
 application: supporting network
applications
 FTP, SMTP, HTTP
 transport: process-process data
transfer
 TCP, UDP
 network: routing of datagrams from
source to destination
 IP, routing protocols
 link: data transfer between
neighboring network elements
 PPP, Ethernet
 physical: bits “on the wire”
application
transport
network
link
physical

13. 1-13
Network Security
 The field of network security is about:
 how bad guys can attack computer networks
 how we can defend networks against attacks
 how to design architectures that are immune to
attacks
 Internet not originally designed with (much)
security in mind
 original vision: “a group of mutually trusting
users attached to a transparent network” 
 Internet protocol designers playing “catch-up”
 Security considerations in all layers!