OSI LAYER MODEL (PART 2)

    

    In this section, you are expecting to explain on how the data travels from the student’s computer to reach the Ulearn System server which is in the UTeM IT Center. The explanation should be related the OSI Layer Model. Explain the possible network components involves throughout the communications. Illustrate the diagram to support your explanation.

How data travels from student’s computer to reach the Ulearn System server which is in the UTeM it Center.

Assume the scenario is, the student is uploading a document file to the UTeM ULearn System. 

7. Application Layer

This process starts firstly from the student’s computer. The student will access the system using UI through websites or application programs. Data will be sent to the application layer, when the student wants to access the system. The application layer uses https protocol to send commands and specifies the data format. Then, this layer 7 will pass all the information data to the presentation layer.

6. Presentation Layer

In the presentation layer, the data from the application layer will be converted to binary format which can be understood by machines. The data format will be standardized. Encryption and compression will also be provided. This means that this presentation layer will compress the data which improves the efficiency and speed of the data. After that, the new data is passed it to the next layer which is the session layer.

5. Session Layer

In this layer, it facilitates the starting, handling and ending of communications between nodes. The communication session will be initialized by sending requests and responses between the application and the transport layer.  This process determines whether the request sent is valid or not. Then, this layer will manage the data flow and pass the data to the transport layer.

4. Transport Layer

During this transport layer, data is changed or disintegrated into segments that are resembled by the transport layer at server side. This layer also provides multiplexing, which makes the host able to send or receive error corrected data through TCP and UDP protocols. Other than that, at this layer the source and destination port will also be specified. Flow control, port assigning and fragmentation will be done during this layer.

3. Network Layer

This layer facilitates the data transferred to check whether the network layer is necessary or not. 

The network layer provides addressing across the internet and determines the path the data is to be sent. The routing happens in this layer and occurs at the router. The segments from the transport layer will be given the source and destination IP address and those segments become packets. The packets now will be passed to the next layer which is the data link layer.

2. Data Link Layer

This layer makes sure that the information is not corrupted. The packets from the network layer will be broken down into frames and will be delivered to the physical layer for transmission.

1. Physical Layer

The frames are converted to bit streams of ones and zeros and transmitted through a physical medium such as cable, network adaptors, ethernet, etc. This physical layer ensures the bit synchronization and bit synchronization will in return ensure the end-user data is assembled in the correct order it was sent. 

Network Components involved throughout the data communication

    The student needs access to the Ulearn System located in the UTeM IT server. Thus, this involves network components to connect the students to the public network to connect to the UTeM IT server. There are 2 types of computer network components which are hardware components and software components that are required for any installations. The hardware components involved are the client, server, transmission medium, peer and connecting devices such hub, router, access point and modem. The software components involved are the operating system and protocols.

1. Sender : The device that sends the message. Examples of senders are computer, telephones. In this scenario it's the student’s computer.

2. Receiver : The device that receives the message. In this scenario it's the Ulearn System server.

3. Message : Information or data to be communicated. Form of data can be text, numbers, pictures, audio and video. In this case, it is the document file that the student wants to upload.

4. Transmission Medium : The physical path by which a message travels from the sender to the receiver. Some examples of transmission media are coaxial cable, fiber-optic wire.

5. Protocol : Is a set of rules that govern data communications. Protocol allows two device that are connected to communicate.