Networking and Security: Overview of OSI and TCP/IP Models

A
Report
On
Networking and Security

Introduction
Computer Networking is a type of telecommunication network that incorporates a linked
network of various computing devices and is also a medium to share resources. This report
wholly discusses about how the connectivity is made among computing devices and systems.
It also includes a brief overview of layers of OSI model and TCP/IP referencing model that
makes this connectivity possible.
Lecture-1
This lecture describes how the data is transmitted over any network, starting from number
system which enables any computer to understand the inputs and translate the values to give
the desired output. There are four number system that are used in networking.
a. Decimal number system with base 10, it represents quantities and addresses IPv4
protocol. (Mirkovic, Dietrich, Dittrich, & Reiher, 2004, p.7).
b. Binary number system represents how the data is stored into the system and it can be
used to examine bits in data.
c. Hexadecimal number system addresses IPv6 protocols and represents relatively larger
quantities. Basically it is a shorthand way to write large binary numbers.
d. Octal number system is used for modifying Linux permissions.
Wireshark is a Protocol Analyser and thusly can catch the parallel information that
comprised arrange movement and after that dissect and show that information in approaches
to enable us to comprehend it. Wireshark is use all through the systems administration
industry as isn't just vital to us, yet in addition to arrange engineers around the world.
Virtualization supports server farms around the world. We are just worried about its
utilization as a work area client; anyway its venture into industry is significant.
Lecture-2
In this, operation of basic networking hardware like NIC, Hubs, Switches and routers is
discussed. In Circuit Switched systems a committed channel is set up before information
being sent. (Shin, 2010) The best case of a circuit exchanged system is the Plain Old
Telephone System (POTS) as utilized in numerous organizations and homes. Once the

circuit is set up, you and the individual on the opposite end of the phone successfully have a
wire interfacing the two phones for the span of the phone call. This course anyway is
basically worried about Packet Switched systems. Example of packet switched network is
ARPANET. It stands for Advanced Research Projects Agency Network. It incorporates both
packet switching and TCP/IP protocols. Earlier Interface Message Processors (IMPs) were
used to connect to network and nowadays routers fulfil the need.
Packet Switching is done in offices using Wifi, cables in homes, larger networks like
business or university networks using optical fibre. This devices are interconnected by NIC
cards, routers, network hubs etc. The data transmission over the network is based on two
network models i.e. OSI and TCP/IP model. These models can handle small packets of data.
For large amount of data transmission it has to be fragmented (at the beginning) and
reassembly at the destination. The transmission of data is described by these two network
models.
Lecture 3
OSI and TCP/IP referencing model is a virtual model that shows how the data is transmitted
over network. These two models have different number of layers. OSI has seven layers
whereas TCP/IP has 4 layers. (Hidalgo, Siu, Nemunaitis, Rizzo, Hammond, Takimoto,
Ferrante, 2001, p.7).
Application layer is common in both models. This layer is the user interface and enables user
to get access to interact with thousands of services and devices over the internet and on local
network. It has categories of interaction:
a. Client/server architecture- In this client request services from the server like a web client
request web pages from web servers.
b. Peer to peer architectures- In this, each machine in the system can go about as both a
server and a customer (at the same time if required). All machines (peers) can share
assets (document and printers) and can likewise get to any mutual asset.
c. Host based architectures- Each system has mainframe connected to terminals and this
mainframe performed all the processing.
d. Cloud based architecture- It can supply a scope of administrations to associations
including the processing stage, working frameworks and programming.