🎁 New User? Get 20% off your first purchase with code NEWUSER20 · ⚡ Instant download · 🔒 Secure checkout Register Now →
Menu

Categories

Networking Beginner

What is OSI Model?

The seven-layer Open Systems Interconnection model that standardizes network communication functions from physical transmission to application protocols.

The OSI model divides networking into seven abstraction layers: Layer 1 Physical (cables, signals), Layer 2 Data Link (Ethernet frames, MAC addresses), Layer 3 Network (IP packets, routing), Layer 4 Transport (TCP/UDP segments, ports), Layer 5 Session (connection management), Layer 6 Presentation (encryption, compression), and Layer 7 Application (HTTP, DNS, SMTP). Each layer serves the layer above it and is served by the layer below. While the internet primarily follows the simpler TCP/IP model (4 layers), the OSI model remains the standard framework for discussing and troubleshooting network issues by layer.

Related Terms

TCP vs UDP
Two transport layer protocols: TCP provides reliable, ordered delivery while UDP provides fast, connectionless delivery without guarantees.
DHCP
A protocol that automatically assigns IP addresses and network configuration to devices on a network.
Port
A numbered endpoint (0-65535) that identifies specific processes or services on a networked computer for communication.
WireGuard
A modern, lightweight VPN protocol that uses state-of-the-art cryptography and minimal code for fast, secure tunneling.
MTU (Maximum Transmission Unit)
The maximum size of a data packet that can be transmitted over a network without fragmentation.
Proxy Server
An intermediary server that forwards requests between clients and destination servers, providing caching, filtering, or anonymity.
 View All Networking Terms →