OSI Model Network Layer: Primary Function and Fundamentals

Study Notes

Network Layer Introduction

The Network Layer is the 3rd layer of the OSI model and is responsible for managing host and network addressing, sub-networks, and internetworking.

Layer-3 Functionalities

The primary focus of devices that work on the Network Layer is routing.
Routing tasks include:
- Addressing devices and networks
- Populating routing tables or static routes
- Queuing and forwarding data according to quality of service constraints
- Internetworking between different subnets
- Delivering packets to destination with best efforts
The Network Layer provides both connection-oriented and connectionless mechanisms.

Network Layer Features

Quality of service management
Load balancing and link management
Security
Interrelation of different protocols and subnets with different schema
Different logical network design over the physical network design
L3 VPN and tunnels can be used to provide end-to-end dedicated connectivity
Internet protocol is a widely deployed Network Layer protocol that enables end-to-end communication between devices over the internet.

Description

Learn about the basics of the Network Layer (Layer 3) in the OSI model, including its responsibilities, functionalities, and devices that work on this layer. Understand how it manages host and network addressing, sub-networks, and internetworking.