Open System Interconnection Model/ OSI Model/ 7 layers explained скачать в хорошем качестве

Open System Interconnection Model/ OSI Model/ 7 layers explained

OSI MODEL In order to accomplish successful communication between two computers the model was introduced by ISO in 1984 7 Layers : 1. Application Layer 2. Presentation Layer 3. Session Layer 4. Transport Layer 5. Network Layer 6. Data Link Layer 7. Physical Layer Application Layer Network Applications provide services with the help of protocols like HTTP, FTP, POP, SMTP, Presentation Layer Performs three major functions Translation: converts characters and numbers to machine understandable binary Compression: reduction of number of bits that are used to represent the original data Encryption/decryption : to maintain the integrity of data before transmission the data is encrypted. Session Layer It helps in setting up and managing connections enabling sending and receiving of data followed by termination of connections or sessions performs three major functions Authentication Authorization Session Management Transport Layer Controls the reliability of communication through Segmentation Flow control Error control Network Layer works for the transmission of received data segments from one computer to another Logical Addressing Path Determination Routing Data Link Layer Physical addressing is done in this layer where MAC address of sender and receiver are assigned to each data packet to form a frame Access Media Controls how data is placed and received from media Physical Layer it converts the binary sequence into signal and transmit over local media Electrical signals light signals Radio Signals