This course provides an extension of the Computer Networks introductory course and provides a more in-depth overview of congestion control mechanisms using in Computer Networks.

Introduction: A short summary review of the layered network model

TCP Congestion Control - a core component of how reliable data transmission is maintained over networks.

Congestion Overview

• Introduces the problem of “network congestion”.
• Describes symptoms like increased delays, packet loss, and retransmissions.
• Explains that unmanaged congestion can collapse performance for all users.

Fairness of Allocations

• Explores how bandwidth should be fairly shared among users.
• Discusses “max-min fairness” and “proportional fairness”.
• Analyses trade-offs between fairness and efficiency.

Additive Increase - Multiplicative Decrease (AIMD)

• Describes TCP’s method for adapting to congestion:
• “Additive Increase”: Gradually increases sending rate to probe for available bandwidth.
• “Multiplicative Decrease”: Slashes rate quickly on detecting congestion.
• Strikes a balance between “throughput” and “stability”.

History of TCP Congestion Control

• Outlines how congestion control evolved over time, especially after major Internet slowdowns in the late '80s.
• Introduces key algorithms and milestones in TCP development.

ACK Clocking

• Explains how “acknowledgment (ACK) packets” act as a pacing mechanism.
• Sending is “clocked” by the receipt of ACKs, helping to avoid flooding the network.

TCP Slow-Start

• Introduces how a TCP connection begins transmission:
• Starts conservatively.
• Doubles the sending rate each RTT until signs of congestion appear.

TCP Fast Retransmit / Fast Recovery

• “Fast Retransmit”: Quickly detects and resends lost packets (using duplicate ACKs).
• “Fast Recovery”: Avoids going all the way back to slow-start, speeding up recovery. 

Explicit Congestion Notification (ECN)

• A modern enhancement to signal congestion “before” packet loss.
• Routers mark packets instead of dropping them, and endpoints respond by reducing their rate.

Upon completion of the course, learners will be able to understand and explain in details the reasoning behind and the functioning of the TCP/IP Protocol’s Congestion handling methods. 

• Presentation
• Interactive discussions
• Questions & Answers
• Quizzes and learning checks