CARA KERJA OSI LAYER

Summary

This video explains the OSI model, a communication standard in computer networks developed by ISO in 1977. It breaks down the seven layers, from the Application layer (handling how apps access networks) to the Physical layer (defining network transmission methods). Each layer's function is demonstrated through real-world examples like browsing the internet, sending emails, and using internet banking. The OSI model is crucial for network communication, ensuring seamless data transmission and connectivity. The video highlights its importance in the development of computer networks, especially for companies like IBM and Apple.

Takeaways

• 😀 The OSI model is a standard for communication within computer networks, allowing different devices to communicate through the network.
• 😀 The Application Layer (Layer 7) interfaces with applications and manages how they access the network, handling errors like when using web browsers or apps like Skype.
• 😀 The Presentation Layer (Layer 6) translates data from applications into a format that can be transmitted over the network, and encrypts data to ensure privacy.
• 😀 The Session Layer (Layer 5) manages how connections are established, maintained, and terminated, such as logging out from online banking after inactivity.
• 😀 The Transport Layer (Layer 4) breaks data into packets for transmission and ensures they can be reassembled at the destination. TCP and UDP are examples of protocols used here.
• 😀 The Network Layer (Layer 3) defines IP addresses and routes data packets through networks using devices like routers and switches.
• 😀 The Data Link Layer (Layer 2) organizes data into frames and controls how devices access the network medium, utilizing protocols like MAC and LLC.
• 😀 The Physical Layer (Layer 1) deals with the physical transmission of data, including cables and network topologies like Ethernet or fiber optics.
• 😀 The OSI model was created by ISO in 1977 in Europe and has been instrumental in the development of network communication, supporting technological progress in computers like IBM and Apple.
• 😀 The OSI model enables devices to communicate effectively, despite differences in hardware or software, and ensures that data is transmitted securely and reliably across networks.

Q & A

What is the OSI model, and why is it important?

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes how different network protocols interact within seven layers. It is crucial because it helps network professionals understand and troubleshoot communication across computer networks.

What does the Application Layer do in the OSI model?

The Application Layer serves as the interface between applications and the network. It manages how applications access the network and handles error messages. Examples of applications using this layer include web browsers and email clients.

What role does the Presentation Layer play in the OSI model?

The Presentation Layer is responsible for translating, encrypting, and compressing data. It ensures that data can be transmitted in a format compatible with the network and often encrypts the data to ensure security.

Can you explain the function of the Session Layer?

The Session Layer manages the sessions between devices, defining how connections are established, maintained, and terminated. For instance, when a user is inactive on a banking website, the session may automatically end for security reasons.

How does the Transport Layer ensure reliable communication?

The Transport Layer divides data into smaller packets for transmission and ensures that these packets are reassembled correctly at the destination. Protocols like TCP (Transmission Control Protocol) handle the reliability of this process.

What does the Network Layer do?

The Network Layer defines the addressing system (like IP addresses) and handles the routing of data packets across networks. It determines the best path for the data to travel using routers and switches.

What is the Data Link Layer responsible for?

The Data Link Layer is responsible for formatting data into frames, controlling access to the network, and ensuring error-free data transmission. Devices like bridges and switches operate at this layer.

What is the main function of the Physical Layer?

The Physical Layer defines the physical medium for data transmission, such as cables, fiber optics, or wireless systems. It ensures that data is transmitted in the form of electrical or optical signals.

Which protocols work at the Network Layer?

At the Network Layer, protocols like IP (Internet Protocol), ARP (Address Resolution Protocol), and ICMP (Internet Control Message Protocol) work to manage packet routing, addressing, and network communication.

What happens if the network is interrupted while sending data at the Transport Layer?

If the network is interrupted during data transmission at the Transport Layer, the sending device will typically request that the data be retransmitted, ensuring reliable communication through protocols like TCP.