16/10/2024
The OSI (Open Systems Interconnection) model has seven layers, each responsible for specific functions in network communication. Here are the layers from top to bottom:
1. Application Layer (Layer 7): Interfaces directly with the user and applications, providing services such as email, file transfer, and web browsing.
2. Presentation Layer (Layer 6): Translates data between the application layer and the network, ensuring proper data formatting, encryption, and compression.
3. Session Layer (Layer 5): Manages sessions between two communicating devices, controlling the start, maintenance, and termination of connections.
4. Transport Layer (Layer 4): Ensures end-to-end communication, providing reliable data transfer, error correction, and flow control. Protocols like TCP and UDP operate here.
5. Network Layer (Layer 3): Manages logical addressing and routing of data packets across networks. This layer includes IP addressing and routing.
6. Data Link Layer (Layer 2): Responsible for node-to-node data transfer, error detection, and handling physical addressing (MAC addresses). It is divided into two sub-layers: MAC and LLC.
7. Physical Layer (Layer 1): Deals with the physical transmission of raw data over a medium (like cables, radio waves), including hardware like cables, switches, and network interface cards.
These layers work together to ensure that data is transmitted effectively and reliably across networks.
