Network Layer - Gate Smashers

May 30, 2024

Network Layer - Gate Smashers

Introduction

  • Position: Third layer from bottom in the OSI Model
  • Function: Takes data from the Transport Layer and passes to the Data Link Layer

Main Responsibilities

1. Host to Host Delivery

  • Alternate Names: Source to Destination delivery, Machine to Machine delivery
  • Function: Responsible for transferring messages from source machine to destination machine across different networks
  • Example: Involves routing messages from network A to network B through intermediate routers if direct communication is not possible.
  • Mechanism: Utilizes IP addresses (Logical Address) which are combinations of Network ID and Host ID

2. IP Addressing

  • Components: Network ID and Host ID
  • Importance: Determines which network and which machine in that network to send the message

3. Routing

  • Function: Determines the path the message should take to reach the destination
  • Protocols Used: RIP (Routing Information Protocol), OSPF (Open Shortest Path First)
  • Routing Devices: Routers (primary), bridges, switches, firewalls
  • Role of Routers: Routers use routing algorithms to determine the best path for data packets

4. Fragmentation

  • Purpose: Divides large packets into smaller fragments suitable for the network
  • Need: Ensures packets can be handled by routers with different capacities

5. Congestion Control

  • Usage: More commonly managed in the Transport Layer, but discussed in Network Layer
  • Methods: Leaky Bucket, Token Bucket
  • Protocols: ICMP (Internet Control Message Protocol), IGMP (Internet Group Management Protocol)
  • Function: Controls network load and prevents congestion by sending control messages to adjust data transmission rates

Key Devices Used

  • Routers: Integral to Network Layer; makes routing decisions using algorithms
  • Switches and Bridges: Can also be used but primarily belong to the Data Link Layer

Conclusion

  • The Network Layer plays a crucial role in ensuring effective data communication through Host to Host delivery, IP addressing, routing, fragmentation, and congestion control.
  • Importance of standardized protocols to ensure efficient data transfer.

Thank you.