OSI Layers

CCNA

OSI Layer 1

Physical layer responsible for transmitting raw bitstreams over a physical medium.

OSI Layer 2

Data link layer that handles node-to-node data transfer and error detection.

OSI Layer 3

Network layer responsible for routing data packets between devices across different networks.

OSI Layer 4

Transport layer that ensures reliable data transfer and manages error recovery and flow control.

OSI Layer 5

Session layer that manages sessions between applications, handling connection establishment, maintenance, and termination.

OSI Layer 6

Presentation layer that translates data formats, encrypts, and compresses data for application use.

OSI Layer 7

Application layer that provides network services directly to user applications, facilitating communication and data exchange.