The document outlines the layers of data communication and computer networks, focusing on the OSI model. It describes the responsibilities of each layer, from the physical layer transmitting bits to the application layer providing services to the user. Key functions include node-to-node delivery, packet delivery, and process-to-process message delivery.

1. Data Communication
and Computer Networks
[EEE 314]
Mubashir Husain RehmaniMubashir Husain Rehmani
Assistant Professor
Department of Electrical Engineering
COMSATS Institute of Information Technology,
Wah Cantt, Pakistan

2. Layers: Sending a Message

3. Intenet Layers

4. Peer to Peer Processes

5. An Exchange using Internet
Model

6. Physical Layer

7. Physical Layer
The physical layer is responsible for
transmitting individual bits from one
node to the next.node to the next.

8. Data Link Layer

9. Data Link Layer
The data link layer is responsible for
transmitting frames from
one node to the next.one node to the next.

10. Node-to-Node Delivery

11. An Example

12. Network Layer

13. Network Layer
The network layer is responsible for the
delivery of packets from the original
source to thesource to the
final destination.

14. Source to Destination Delivery

15. Transport Layer

16. Transport Layer
The transport layer is responsible for
delivery of a message from one process
to another.to another.

17. Process to Process Delivery of
Message

18. An Example

19. Application Layer

20. Application Layer
The application layer is responsible for
providing services to the user.

21. Duties of Layers

22. OSI Model