CHAPTER 3: OSI REFERENCE MODEL
3.1 Purpose
A conceptual framework that standardizes network communication.
3.2 Layers and Functions
Layer 7: Application
Interfaces with applications
Protocols: HTTP, FTP, SMTP, DNS
Layer 6: Presentation
Encryption, compression, data translation
Example: SSL/TLS
Layer 5: Session
Manages communication sessions
Example: NetBIOS
Layer 4: Transport
Segmentation, flow control
Protocols: TCP, UDP
Layer 3: Network
Routing, IP addressing
Protocols: IP, ICMP, ARP
Layer 2: Data Link
MAC addressing, frames
Protocols: Ethernet
Layer 1: Physical
Cables, signals
Standards: RJ45, Fiber optic, Wi-Fi
3.1 Purpose
A conceptual framework that standardizes network communication.
3.2 Layers and Functions
Layer 7: Application
Interfaces with applications
Protocols: HTTP, FTP, SMTP, DNS
Layer 6: Presentation
Encryption, compression, data translation
Example: SSL/TLS
Layer 5: Session
Manages communication sessions
Example: NetBIOS
Layer 4: Transport
Segmentation, flow control
Protocols: TCP, UDP
Layer 3: Network
Routing, IP addressing
Protocols: IP, ICMP, ARP
Layer 2: Data Link
MAC addressing, frames
Protocols: Ethernet
Layer 1: Physical
Cables, signals
Standards: RJ45, Fiber optic, Wi-Fi
