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Networking Models: OSI vs TCP/IP

·137 words·1 min
Author
Zain Chand
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The OSI Model
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OSI Model Encapsulation

The Open Systems Interconnection (OSI) model is a conceptual framework used to describe the functions of a networking system. It consists of seven layers:

  1. Physical Layer: Hardware specifications, cables, and switches.
  2. Data Link Layer: MAC addresses and frame forwarding.
  3. Network Layer: IP addresses and routing.
  4. Transport Layer: TCP/UDP, port numbers, and reliability.
  5. Session Layer: Establishing, maintaining, and terminating sessions.
  6. Presentation Layer: Data formatting, encryption, and compression.
  7. Application Layer: End-user applications (HTTP, FTP, SMTP).

The TCP/IP Model
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The TCP/IP model is a more practical, four-layer model that maps closely to the actual protocols used on the Internet:

  1. Network Access (or Link) Layer: Combines OSI layers 1 and 2.
  2. Internet Layer: Corresponds to the OSI Network layer.
  3. Transport Layer: Corresponds to the OSI Transport layer.
  4. Application Layer: Combines OSI layers 5, 6, and 7.