2.1 Project Report
For this project, each team is expected to produce writing related to the project scenario. From the scenario, you are expecting to produce a report on three major sections which are:
- OSI Layer Model
In this section, you are expecting to explain how the data travels from the student’s computer to reach the Online Learning System server which is in the OUM IT Centre. 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.
The open systems interconnection (OSI) model is a conceptual model created by the International Organization for Standardization which enables diverse communication systems to communicate using standard protocols. It is a 7 layer architecture with each layer having specific functionality to perform. All these 7 layers work collaboratively to transmit the data from one person to another across the globe.
The lowest layer of the OSI reference model is the physical layer. It is capable of the extreme transmission of computerized information bits from the source gadget over network communications to the destination gadget. When the OUM student attempt to access the online learning, the system found in OUM organize offices, the information penetrate through the physical layer in the first place. The modem of student has used to associate the open/public network to able to associate to the OUM offices. Thus, the unstructured crude bit-stream information that sent over a physical medium is being used in this layer and the information stream is in the form of bits.
The data link layer is responsible for the node to node delivery of the message. DLL is responsible to transmit the packet to the Host using its MAC address when it arrives in a network. In this layer, the unstructured raw data from the physical layer transformed into a reliable link in the student’s gadget. Then, the packet received from the Network layer is further divided into frames depending on the frame size of the student’s NIC(Network Interface Card) which consist of header and trailer. DLL also encapsulates Sender and the receiver’s MAC address in the header and the trailer is responsible for detection where it will eliminate any damaged or duplicated frame at once.
The network layer works for the transmission of data from one host to the other located in different networks. In this layer, protocols determine which route is suitable from source to destination. This function of the network layer is known as routing. In order to identify each device on internetwork uniquely, the network layer defines an addressing scheme where the sender & receiver’s IP address is placed in the header by the network layer. Such an address distinguishes each device uniquely and universally. Besides, each frame that consists of source and destination IP address are examined further to determine if it reached its destination in this layer
Transport layer provides services to the application layer and takes services from the network layer. The data in the transport layer is referred to as Segments. In this layer, the port address is added by the transport layer into the header when the student uploads any file in the Online Learning System. Then, the data is further experienced the main function of the transport layer which is segmentation and reassembly. This layer accepts the message from the (session) layer, breaks the message into smaller units. Each of the segment produced has a header associated with it. The transport layer at the destination station reassembles the message. To deliver the message to the correct process, the transport layer header includes a type of address called service point address or port address. Thus, by specifying this address, the transport layer makes sure that the message is delivered to the correct process.
This layer is responsible for the establishment of connection, maintenance of sessions, authentication and ensures security. As we know from the scenario that the student intends to access the Online Learning System, a connection is established between the OUM student’s home network and the server. The server further checks the user’s credentials by allowing them to insert their login information. Then, the session layer manages and synchronize the conversation, where the streams of data are marked and are resynchronized properly, so that the ends of the messages are not cut prematurely, and data loss is avoided. Also, this layer allows a dialog control where it allows two systems to start communication with each other in half-duplex or full-duple
The presentation layer is also called the Translation layer. The data from the application layer is extracted here and manipulated as per the required format to transmit over the network. This layer translates the data for instance from ASCII to EBCDIC. Next, the data encryption translates the data into another form or code. The encrypted data is known as the ciphertext and the decrypted data is known as plain text. A key value is used for encrypting as well as decrypting data. Also, compression is taking place in the presentation layer as reduces the number of bits that need to be transmitted on the network.
We could find the Application layer at the very top of the OSI Reference Model stack of layers, which is implemented by the network applications. These applications produce the data, which must be transferred over the network. This layer also serves as a window for the application services to access the network and for displaying the received information to the user. Simply, this layer provides network services to the end-user. For instance, when OUM student successfully accessed the Online Learning System, they could be able to view the portal which has different kind of services where they could choose which they want to perform.
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