JNTU B.Tech IV COMPUTER NETWORKS Previous Question Paper (July/August - 2022 - R16)

The Open Systems Interconnection (OSI) reference model is a conceptual framework developed by the ISO to standardize the functions of a telecommunication or computing system into seven distinct layers. Each layer provides specific services to the layer above it and receives services from the layer below it.

The seven layers are:

1. Physical Layer: Handles the transmission of raw bit streams over a physical medium. It defines mechanical, electrical, and procedural interfaces.
2. Data Link Layer: Responsible for node-to-node data transfer, framing, physical addressing (MAC), and error detection/correction.
3. Network Layer: Manages logical addressing (IP), routing, and packet forwarding across different networks.
4. Transport Layer: Ensures end-to-end communication, flow control, segmentation, and error recovery (e.g., TCP, UDP).
5. Session Layer: Establishes, maintains, and terminates sessions between applications.
6. Presentation Layer: Handles data translation, encryption, decryption, and compression to ensure the application layer can read the data.
7. Application Layer: Provides network services directly to user applications, such as HTTP, FTP, and SMTP.

Diagrammatic Representation (Conceptual Flow):

The model facilitates interoperability between diverse systems by ensuring that manufacturers follow a common protocol stack, allowing different hardware and software to communicate effectively across a network.