OSI Reference Model

The Open Systems Interconnection (OSI) model is a conceptual framework that standardizes network communication functions into seven distinct layers, developed by the International Organization for Standardization (ISO) in 1984.

Overview and Purpose

• OSI Model History and Development
• Why the OSI Model Matters
• OSI vs Other Network Models

Layer Deep Dives

• Layer 7: Application Layer in Detail
• Layer 6: Presentation Layer in Detail
• Layer 5: Session Layer in Detail
• Layer 4: Transport Layer in Detail
• Layer 3: Network Layer in Detail
• Layer 2: Data Link Layer in Detail
• Layer 1: Physical Layer in Detail

OSI Model in Practice

• Data Encapsulation and Decapsulation Process
• Protocol Data Units Across Layers
• Header Analysis by Layer
• Cross-Layer Interactions

Cybersecurity Perspectives

• Attack Vectors by OSI Layer
• Defense Strategies by Layer
• Layer-Specific Security Tools
• OSI-Based Security Assessment

Troubleshooting with OSI

• Bottom-Up Troubleshooting Approach
• Top-Down Troubleshooting Approach
• Identifying Problems by Layer
• OSI-Based Network Diagnostics

Related Topics

• Comparing OSI and TCP/IP
• TCP/IP Protocol Suite
• Network Protocols by Layer

Key Terms

• Encapsulation
• Protocol Data Unit
• Headers and Trailers
• Layer Interface Points

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