Communication Layers in Networks
Computer networks rely on structured models to manage the complexity of communication.
The OSI model and the TCP/IP model use layered architectures that break down network functions into smaller, manageable parts, ensuring interoperability, scalability, and easier troubleshooting.
Advantages of Layered Architecture
- Simplification: Breaking communication into layers makes complex processes manageable.
- Isolation: Changes in one layer do not affect others, allowing for independent development and troubleshooting.
- Interoperability: Different vendors can develop products for specific layers, ensuring compatibility across devices.
- Scalability: New technologies can be integrated into a specific layer without affecting the entire system.
Understanding network layers is essential for designing, implementing, and troubleshooting communication systems.
The OSI Model
| No. | Part | Layer | Purpose | Example protocols |
|---|---|---|---|---|
| 7 | Software | Application Layer | Interfaces with end-user applications | HTTP, FTP, SMTP |
| 6 | Software | Presentation Layer | Translates data formats, handles encryption and compression | SSL/TLS, JPEG, PNG |
| 5 | Software | Session Layer | Manages sessions between applications | NetBIOS, RPC |
| 4 | Transport Layer | Ensures reliable data transfer | TCP, UDP | |
| 3 | Hardware | Network Layer | Routes data between devices | IP, ICMP |
| 2 | Hardware | Data Link Layer | Handles error detection and correction in data frames | Ethernet, Wi-Fi |
| 1 | Hardware | Physical Layer | : Transmits raw bits over physical media | RS-232, USB |
- The Application Layer is where users interact with the network, using applications like web browsers and email clients.
- Think of the Presentation Layer as a translator, ensuring data is in a format both sender and receiver understand.
- The Transport Layer breaks data into segments and ensures they are reassembled correctly at the destination.
- The Physical Layer is the foundation of the OSI model, dealing with the actual transmission of bits over cables, radio waves, or other media.
- The OSI model is a reference model, not a protocol suite.
- It provides a conceptual framework for understanding network communication.
The TCP/IP Model
Note- The TCP/IP model is more streamlined than the OSI model, with only four layers.
- It is the foundation of the internet and most modern networks.
- Application Layer
