Computer Network Layer- Concept of OSI Layer and tcp ip layer or tcp ip protocol.
Computer Network Layer- Concept of OSI Layer and tcp ip layer or tcp ip protocol.
Contents [hide]
- 1 Computer Network Layers – OSI Model & TCP/IP Model
- 2 OSI Model (7 Layers)
- 3 OSI Model Layers & Their Functions
- 4 Easy Way to Remember OSI Layers (Top to Bottom)
- 5 TCP/IP Model (4 Layers)
- 6 OSI vs TCP/IP Model
- 7 TCP/IP Protocols (Used in Internet)
- 8 Key Differences Between OSI & TCP/IP Model
- 9 Conclusion
- 10 Computer Network Layer- Concept of OSI Layer and tcp ip layer or tcp ip protocol.
- 11 Data Encapsulation & OSI & TCP/IP Models Week 2
- 12 The OSI Model and the TCP/IP Protocol Suite
- 13 UNIT 2 OSI AND TCP/IP MODELS
- 14 Network Models OSI vs. TCP/IP
- 15 Chapter 2 Network Models
Computer Network Layers – OSI Model & TCP/IP Model
Computer networks follow a structured model to enable communication between devices. The two main models used are:
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OSI Model (Open Systems Interconnection Model)
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TCP/IP Model (Transmission Control Protocol/Internet Protocol Model)
OSI Model (7 Layers)
The OSI Model has 7 layers, each responsible for a specific function in data transmission.
OSI Model Layers & Their Functions
| Layer No. | Layer Name | Function |
|---|---|---|
| 7 | Application | Interface for user applications (e.g., Web browser, Email) |
| 6 | Presentation | Data formatting, encryption, compression (e.g., SSL, JPEG) |
| 5 | Session | Manages sessions (start, maintain, end connections) |
| 4 | Transport | Reliable or unreliable data transmission (e.g., TCP, UDP) |
| 3 | Network | Routing, logical addressing (IP addresses) |
| 2 | Data Link | MAC addressing, error detection (e.g., Ethernet, ARP) |
| 1 | Physical | Transmission of raw bits (e.g., cables, WiFi, fiber optics) |
Easy Way to Remember OSI Layers (Top to Bottom)
“All People Seem To Need Data Processing”
(A = Application, P = Presentation, S = Session, T = Transport, N = Network, D = Data Link, P = Physical)
TCP/IP Model (4 Layers)
The TCP/IP Model is a simpler model used in the real-world Internet. It has 4 layers:
| Layer No. | Layer Name | OSI Equivalent | Function |
|---|---|---|---|
| 4 | Application | (Application + Presentation + Session) | Handles application protocols (HTTP, FTP, SMTP) |
| 3 | Transport | Transport | Reliable/Unreliable data transmission (TCP, UDP) |
| 2 | Internet | Network | Logical addressing & routing (IP, ICMP, ARP) |
| 1 | Network Access | (Data Link + Physical) | Data transfer via hardware (Ethernet, WiFi) |
OSI vs TCP/IP Model
| Feature | OSI Model | TCP/IP Model |
|---|---|---|
| Number of Layers | 7 | 4 |
| Used in Real-World? | No | Yes (Internet-based model) |
| Complexity | More Complex | Simpler |
| Main Protocol | Theoretical Model | TCP/IP Protocol Suite |
TCP/IP Protocols (Used in Internet)
| Layer | Common Protocols |
|---|---|
| Application | HTTP, HTTPS, FTP, SMTP, DNS |
| Transport | TCP, UDP |
| Internet | IP, ICMP, ARP |
| Network Access | Ethernet, WiFi, PPP |
Key Differences Between OSI & TCP/IP Model
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OSI Model is conceptual, whereas TCP/IP is practical and used in the Internet.
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OSI has 7 layers, TCP/IP has only 4 layers.
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OSI model separates Presentation & Session layers, but TCP/IP combines them into the Application layer.
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TCP/IP follows a client-server model and is the foundation of modern networking.
Conclusion
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OSI Model is used for learning and understanding network architecture.
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TCP/IP Model is used in real-world networking (Internet, websites, emails, etc.).
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Understanding TCP/IP protocols (like HTTP, TCP, IP, etc.) is crucial for network engineers, cybersecurity, and software developers.
Do you want a practical example or a deeper explanation of any layer?