OSI MODEL APPLICATIONS

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DATA COMMUNICATION AND NETWORKING

 Project Scenario        

The scenario of this project can be referred to Figure 1. Figure 1 shows the logical network flow from a home network to UTeM facilities. In this figure, a UTeM’s student is trying to access the Ulearn system located in the UTeM network facilities. The student is using her modem to connect to the public network before able to connect to the UTeM facilities. From the UTeM network, the data then was forwarded to IT Center where the Ulearn System server is located.


Figure 1: Logical Network Flow

 


 

 

OSI Model


TABULATION OF OSI MODEL AND FUNCTIONALITIES

NO

OSI LAYER

FUNCTIONS

WHAT IS INSIDE

1.

Application Layer

·        Responsible for providing services to the layer incorporated.

·        mail services

·        www access / SMTP /HTTP


 

DATA

2.

Presentation Layer

·        Responsible for syntax and semantics of information translation (bit streams) and encrypt or decrypt the data while compressing them

 

DATA

3.

Session Layer

·        Establishes and syncronises the interaction between systems

·        dialog control

·        syncronisation

 

DATA

4.

Transport Layer

·        Delivery of message from one process to another by few method :

  • port addressing 
  • segmenting 
  • connection control
  • flow control
  • error control

 

SEGMENTS

5.

Network Layer

·        Responsible for delivery of packets from original source to destination

·      IP address of both device(segment) is packet-ed

 

 


 

**Logical addressing is needed to go off IP boundaries of LAN

 

 

PACKETS

6.

Data link Layer

·        Packets are framed and transmitted from node-node

·        Header of packets are MAC addresses of both sender and reciever 

 

FRAMES

7.

Physical

·        Physical media Transmission

·        Responsible for transmitting individual bits from node to next 

  • cable,Hub

BITS

 

 EXPLANATION OF THE GIVEN SCENARIO

 

 

 

When the student connects to the internet he uses his own modem and he uses the network approach of WAN (wide area network) . He connects his machine to the WiFi that is available at home in order to surf the web . The UTeM private network uses Campus Area Network (CAN) to connect between the IT centre and the FTMK faculty.

 

Application Layer

When he surf to the Ulearn page immediately The browser sends an HTTP request message  to the server, asking it to send a copy of the website to the client  across the students internet connection using OSI model configuration.

Presentation layer

Makes sure that data from UTEM and from the Students modem is  accurate to all the devices which are there in a closed network.

Session layer

Enables both the networks and machines to have a stable and synchronized connection via dialog control.  

Transport Layer

The rate and the amount of data that should be sent from the students machine is determined

 

Network Layer

Since the student is currently trying to access details form the FTMK course page in ulearn the IT centre then asks request from the FTMK servers .the server then  sends the website's files to the browser as a series of small chunks called data packets

 

Data Link

The stream of information is now packeted and header of packets are MAC addresses of both sender and receiver.

 

Physical Layer

The modem that the student used is the transmission medium between the UTeM CAN and the WAN connection.

 

 

 

 

 

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