Transport layer: TCP, UDP, QUIC, ports, and sockets

Transport layer: TCP, UDP, QUIC, ports, and sockets are the core concepts of this lesson, which focuses on end-to-end communication between application processes.

The text explains that the transport layer is responsible for providing a logical communication channel between applications by leveraging network layer services. The main transport protocols—TCP, UDP, and QUIC—are then introduced.
TCP offers reliable, connection-oriented communication through mechanisms such as acknowledgments (ACKs), retransmission, flow control, and congestion control. UDP, on the other hand, is a simpler, faster, connectionless, and unreliable protocol, making it suitable for real-time communications such as streaming, VoIP, online gaming, and IoT applications.

The lesson also introduces QUIC, a modern protocol based on UDP but designed to deliver faster, more secure, and more efficient communication, particularly for the modern Web and HTTP/3. Finally, the concepts of ports and sockets are explained; these are essential for directing data to the correct process and managing communication between applications.

Bibliography

Primary sources

Eddy, W. (Ed.). (2022). Transmission Control Protocol (TCP). RFC 9293. IETF / RFC Editor.

Postel, J. (1981). Transmission Control Protocol. RFC 793. IETF / RFC Editor.

Allman, M., Paxson, V., & Blanton, E. (2009). TCP Congestion Control. RFC 5681. IETF / RFC Editor.

Paxson, V., Allman, M., Chu, J., & Sargent, M. (2011). Computing TCP’s Retransmission Timer. RFC 6298. IETF / RFC Editor.

Postel, J. (1980). User Datagram Protocol. RFC 768. IETF / RFC Editor.

Eggert, L., Fairhurst, G., & Shepherd, G. (2017). UDP Usage Guidelines. RFC 8085. IETF / RFC Editor.

Iyengar, J., & Thomson, M. (2021). QUIC: A UDP-Based Multiplexed and Secure Transport. RFC 9000. IETF / RFC Editor.

Thomson, M., & Turner, S. (2021). Using TLS to Secure QUIC. RFC 9001. IETF / RFC Editor.

Iyengar, J., & Swett, I. (2021). QUIC Loss Detection and Congestion Control. RFC 9002. IETF / RFC Editor.

Bishop, M. (2022). HTTP/3. RFC 9114. IETF / RFC Editor.

IANA. Service Name and Transport Protocol Port Number Registry.

Cotton, M., Eggert, L., Touch, J., Westerlund, M., & Cheshire, S. (2011). Internet Assigned Numbers Authority (IANA) Procedures for the Management of the Service Name and Transport Protocol Port Number Registry. RFC 6335. IETF / RFC Editor.

The Open Group. The Open Group Base Specifications — Sockets.

Secondary sources

Kurose, J. F., & Ross, K. W. Computer Networking: A Top-Down Approach. Pearson.

Tanenbaum, A. S., & Wetherall, D. J. Computer Networks. Pearson.

Comer, D. E. Internetworking with TCP/IP, Volume 1. Pearson.

Comer, D. E. Computer Networks and Internets. Pearson.

Peterson, L. L., & Davie, B. S. Computer Networks: A Systems Approach. Morgan Kaufmann.

Stevens, W. R. TCP/IP Illustrated, Volume 1: The Protocols. Addison-Wesley.

Stevens, W. R., Fenner, B., & Rudoff, A. M. UNIX Network Programming, Volume 1: The Sockets Networking API. Addison-Wesley.

Forouzan, B. A. Data Communications and Networking. McGraw-Hill.

Index

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