Question 1: Name the seven layers of the OSI model in the correct order, starting from the lowest layer to the highest.

Answer: Physical, Data Link, Network, Transport, Session, Presentation, Application

Question 2: Describe the main function of the Transport layer in a network.

Answer: The Transport layer is responsible for end-to-end communication, ensuring data is transferred reliably and in the correct order.

Question 3: Explain the role of the Application layer in a network communication.

Answer: The Application layer provides network services directly to user applications, facilitating tasks like email, web browsing, and file transfer.

Question 4: Identify which layer is responsible for routing data packets across different networks.

Answer: The Network layer.

Question 5: Complete the following table for the OSI model: | Layer Number | Layer Name | Main Function | |--------------|--------------|--------------| | 3 | ? | Routing and addressing | | 4 | ? | ? |

Answer: | 3 | Network | Routing and addressing | | 4 | Transport | End-to-end communication and reliability |

Question 6: Draw a simple diagram to illustrate how data flows through the layers of a network from a computer to a web server. Label each layer involved in the process.

Answer: A layered diagram starting from Application at the top, passing through Presentation, Session, Transport, Network, Data Link, and Physical layers, showing data moving down through the layers on the sender side and up through the layers on the receiver side, with labels indicating each layer.

Question 7: Explain why the Presentation layer is important in network communications.

Answer: The Presentation layer translates data between the application and network formats, handling encryption, decryption, and data formatting to ensure compatibility.

Question 8: Describe what happens at the Data Link layer when a device sends data over a local network.

Answer: The Data Link layer packages data into frames, adds MAC addresses, and manages error detection to ensure reliable delivery within the local network.

Question 9: Identify one protocol associated with the Transport layer and describe its purpose.

Answer: TCP (Transmission Control Protocol); it ensures reliable, ordered delivery of data between devices.

Question 10: Sketch a block diagram representing the three main network layers (Network Interface, Internet, and Transport). Leave space for your drawing. Label each layer clearly.

Answer: A three-layer block diagram with each layer represented as a box: the bottom labeled 'Network Interface', the middle 'Internet', and the top 'Transport'. Arrows should show data moving between layers, illustrating encapsulation.

Question 11: Why is it important for each layer of the network model to have a specific function? Write your answer in 2-3 sentences.

Answer: Having specific functions for each layer simplifies troubleshooting, enhances modular design, and allows different protocols to operate independently. This layered approach makes networks more reliable and easier to maintain.