Layer 3 of the OSI model is known as the Network Layer. Here’s a breakdown of its main functions:
- Routing: The Network Layer is responsible for determining the best path for data to travel from the source to the destination. It uses routing algorithms and protocols to make these decisions and ensure efficient data delivery.
- Logical Addressing: At this layer, devices are assigned logical addresses, such as IP addresses. These addresses are used to identify devices on a network and facilitate the routing process.
- Packet Forwarding: Once the best path is determined, the Network Layer forwards data packets along that path. It ensures that packets move from one network segment to another until they reach their final destination.
- Fragmentation and Reassembly: When data packets are too large to be transmitted over the physical medium, the Network Layer can fragment them into smaller pieces. These fragments are then reassembled at the destination.
- Error Handling and Diagnostics: The Network Layer also handles errors that occur during the routing process and provides diagnostic functions to identify and resolve issues.
Some common protocols that operate at the Network Layer include:
- Internet Protocol (IP): The primary protocol used for routing data on the internet.
- Internet Control Message Protocol (ICMP): Used for network diagnostics and error reporting.
- Address Resolution Protocol (ARP): Used to map IP addresses to physical (MAC) addresses.
In summary, the Network Layer ensures that data is correctly routed and delivered across networks, enabling communication between devices that may be far apart. ata is efficiently routed and delivered from one network to another, managing logical addresses and handling packet forwarding.