ASSIGNMENT NO.2:
BAHADUR Sub- Campus, Layyah
Department Of English :
Subject :
Computer Studies
Topic :
Layer wise TCP/IP & OSI Model Protocols.
Submitted By :
Roll No.
Class:
Muhammad Umar
14
BS English Evening 3rd Semester
Session :
2019 _ 2023
Submitted To ;
Sir Hassan Mohtism
1
Submission Date:
25 -11 -2020
Layer wise TCP/IP & OSI
Model Protocols :
Layer Wise TCP/IP:
TCP/IP is the suite of
communications protocols used to connect
hosts on the internet.
TCP/IP stands for ‘’Transmission Control Protocol
/ Internet Protocol’’ .
Main Purpose:
 The purpose of TCP/IP model is to
allow communication over large
distances.
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 TCP/IP protocol stack is specifically
designed as a model to offer highly
reliable and end to end byte stream
over an unreliable internetwork.
 TCP/IP has since then become the
foundation of the internet.
A
protocol is the set of rules and conventions used in
sending, interpreting and responding to a piece of data. Obviously,
each layer is equipped with the intelligence of the
protocols it needs to use the lower layer’s interface,
provide its own interface to its upper layers and
interact with the corresponding interface on a
different machine. Such a set of layers and protocols
network architecture
is called a
. A list of the
protocols used by a system in these different layers,
is called a protocol stack.
Layers of TCP/IP
Model:
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TCP/IP model have four
layers :
1) Application Layer
2) Transport Layer
3) Internet
4) Network Interface
1) Application Layer :
Application layer is the topmost
layer in the TCP/IP model.
 It is responsible for handling high – level
protocols , issues of representation.
 This layer allows the user to interact with the
application.
Protocols :
Following are the protocols used in the application
layer.
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HTTP,SNMP,SMTP,DNS,TELNET,FTP,NFS,NIS,RI
P,RDISC & others .
HTTP:
HTTP stands for “Hypertext Transfer
Protocol”.
 This protocol allows us to access the data over
the world wide web .
 It transfers the data In the form of plain text ,
audio , video.
SNMP:
SNMP stands for simple “Network
Management Protocol”
 It is a framework used for managing the devices
on the internet by using the TCP/IP protocol
suite .
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SMTP:
SMTP stands for “Simple Mail Transfer
Protocol”.
 Simple Mail Transfer Protocol (SMTP) as an
internet mailing system.
 The TCP/IP protocol that supports the e-mail is
known as a simple mail transfer protocol.
FTP:
FTP stands for “File Transfer Protocol”.

File Transfer Protocol (FTP) for high-speed
disk-to-disk file transfers.
 FTP is a standard internet protocol used for transmitting the
files from one computer to another computer.
TELNET:
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 Telnet for interactive terminal access to
remote internet hosts.
Transport Layer:
 This layer provides backbone to
data flow between two hosts.
 This layer receives data from the
application layer above it .
Protocols:
There are many protocols that work at this
layer, TCP,UDP.
TCP:
Transmission Control Protocol (TCP),
which provides connection-oriented reliable data
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delivery, duplicate data suppression, congestion
control, and flow control.
UDP:
“User Datagram Protocol (UDP)”. It provides
connectionless, unreliable, best-effort service.
Internet Layer:
The internet layer, also called the
internetwork layer or the network layer, provides
the “virtual network” image of an internet (this layer
shields the higher levels from the physical network
architecture ).
 The main responsibility of the internet layer is to
send the packets from any network &they arrive
at the destination irrespective of the route they
take.
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Protocols:
Following are the protocols used in
this layer are :IP, ARP, ICMP,IGMP& RARP.
IP Protocol:
 IP protocol is used in this layer and it is the most
significant part of the entire TCP/IP suite.
Following are the responsibilities of the
protocol:
IP Addressing :
 This protocol implements logical host addresses
known as IP Addresses.
Host - To – Host Communication:
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 It determines the path through which the data is
to be transmitted.
Data Encapsulation and Formatting :
 An IP protocol ensure that the data is sent and
received securely etc.
ARP Protocol :
 ARP stands for “Address Resolution
Protocol”.
 ARP is a network layer protocol which is used
to find the physical address from the IP address.
The two terms are mainly associated with the
ARP protocol.
ARP Request :
 When a sender wants to know the physical
address of the device , it broadcasts the ARP
Request to the network.
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ARP Reply :
 Every device attached to the network will accept
the ARP request and process the request , but
only recipient recognize the IP address and
sends back its physical address in the form of
ARP reply .
ICMP Protocol:
 ICMP stands for “Internet Control Message
Protocol”.
 An ICMP Protocol mainly uses two terms.
ICMP Test:
 ICMP test is used to test whether the
destination is reachable or not.
ICMP Reply:

ICMP Reply is used to check weather the
destination device is responding or not.
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Network Interface Layer:
 The network interface layer, also called the link
layer or the data-link layer, is the interface to
the actual network hardware.
 This interface may or may not provide reliable
delivery, and may be packet or stream oriented.
 In fact, TCP/IP does not specify any protocol
here, but can use almost any network interface
available, which illustrates the flexibility of the IP
layer.
A more detailed layering model is included..
Applicati
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ons
SMTP,TELNENT,FTP,…
……………
Transpo
rt
TCP
UDP
Internet
IP
work
IC AR RA
MP P RP
Network Ethernet ,Token – Ring , FDDI ,
Interface Wireless , Async , ATM
and
Hardwar
e
The Open Systems
Interconnection (OSI)
Reference Model:
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The OSI (Open
Systems Interconnect)
Reference Model
defines as ,seven-layer
model of data
communication with
physical transport at the
lower layer and
application protocols at
the upper layers.
The seven layers are:
The Application Layer:
Network applications
such as terminal
emulation and file
transfer. FTP , TFTP ,
POP3 , SMTP and
HTTP are the few
examples of standards
and protocols used in
this layer .
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The Presentation Layer:
Formatting of data and
encryption. ASCII ,
BMP , GIF , JPEG ,
WAV , AVI , and MPEG
are the few examples of
standards and protocols
used in this layer .
The Session Layer:
 Establishment
and
maintenance of
sessions. RPCs and
NFS are the examples
of the session layer.
The Transport Layer:
Provision of reliable and
unreliable end-to-end
delivery . TCP and UDP
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are the examples of the
transport layer.
The Network Layer:
Packet delivery,
including routing. IP ,
IPX and Apple Talk are
the examples of this
layer.
The Data Link Layer:
Framing of units of
information and error
checking. HDLC , PPP
and Frame Relay are
the examples of this
layer.
The Physical Layer:
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Transmission of bits on
the physical hardware.
CSU/DSU , DCE and
DTE are the few
examples of the
standards used in this
layer.
The OSI Reference Model :
Application
Application
Presentation
Presentation
Session
Session
Transport
Transport
Network
Network
Data link
Data link
Physical
Physical
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