TCP and UDP Comparison

TCP and UDP

• TCP (Transmission Control Protocol) is a connection-oriented protocol. A connection is established between the sender and receiver before data transmission.
• UDP (User Datagram Protocol) is a connectionless protocol. No connection is established before data transmission.
• TCP provides reliable data transfer, ensuring all data is transmitted correctly, completely, and in the correct order.
• TCP employs acknowledgments and retransmissions to guarantee data integrity.
• UDP offers faster data transmission than TCP, lacking the overhead of connection establishment and error checking.
• TCP is suitable for applications requiring reliable transfer, like file transfers and web browsing.
• UDP is preferable for applications needing speed, even with potential data loss, such as video streaming and online gaming.
• TCP incorporates flow control to regulate transmission rate, preventing sender overload of the receiver.
• UDP lacks flow control.

OSI Model

• The OSI (Open Systems Interconnection) model is a conceptual framework defining networking system functions.
• It comprises seven layers, each with distinct responsibilities.
• Layers include:
  • Physical Layer: Transmits raw bit streams over the physical medium.
  • Data Link Layer: Encapsulates bits into frames, controlling physical medium access.
  • Network Layer: Routes packets across networks.
  • Transport Layer: Provides reliable or unreliable data delivery between applications.
  • Session Layer: Establishes, manages, and terminates communication sessions.
  • Presentation Layer: Translates data formats between applications.
  • Application Layer: Provides network services to applications (e.g., email, web browsing).
• Layers interact in a structured manner.
• Each layer adds its header to data before passing it down.
• Headers are removed at each receiving step.

TCP/IP Model

• TCP/IP (Transmission Control Protocol/Internet Protocol) model underpins the internet.
• It's simpler than the OSI model, with only four layers.
• Layers consist of:
  • Network Access Layer: Corresponds to OSI's physical and data link layers, handling physical data transmission.
  • Internet Layer: Corresponds to OSI's network layer, managing packet routing. IP is central in this layer.
  • Transport Layer: Matches OSI's transport layer, providing reliable or unreliable data delivery. TCP and UDP operate here.
  • Application Layer: Corresponds to OSI's session, presentation, and application layers, providing network services to applications.

Comparison of TCP/IP and OSI Models

• Both models are hierarchical, employing layered structures for networking.
• The TCP/IP model is simpler and more practical, reflecting real-world network design better.
• The OSI model is more theoretical, serving as a conceptual framework.
• TCP/IP is used in practical networking; the OSI model is primarily a reference.
• Modern networks predominantly use TCP/IP protocols.
• While more comprehensive, the OSI model hasn't achieved the same standardisation as TCP/IP.