Lecture 19: Congestion Control: The Router's View
The router has a unique view of congestion, as the router is where the congestion actually happens. So, what actions should the router take when it sees long queues of packets? Today's lecture will discuss several different queueing disciplines (FIFO, Round-Robin, Fair Queueing, Weighted Fair Queuing). We will then talk about the Random Early Drop (RED) algorithm in some detail.
Lesson Objectives
By the end of this lesson, the student will be able to:
- describe the differences between packet scheduling algorithms and drop policies.
- describe the algorithm and issues with the following queueing algorithms: FIFO, Priority Queueing, Round Robin, Fair Queuing and Weighted Fair Queueing.
- analyze a scenario using one of the following queueing algorithms: FIFO, Priority Queueing, Round Robin, Fair Queuing and Weighted Fair Queueing.
- describe the opportunities for a router to do congestion control.
- describe the goals and details of the RED Gateway algorithm, as well as its advantages when compared to FIFO or other queueing algorithsm.
- calculate average queue length and drop probability as the RED algorithm does.
Reading
- RED Gateways [Floyd93]
Slides
Due
- Paper Review: Floyd93