Contents

1. Introduction to Linux Traffic Control

   • 1.1 Target audience and assumptions about the reader
   • 1.2 Conventions
   • 1.3 Recommended approach
   • 1.4 Missing content, corrections and feedback

2. Overview of Concepts

   • 2.1 What is it?
   • 2.2 Why use it?
   • 2.3 Advantages
   • 2.4 Disdvantages
   • 2.5 Queues
   • 2.6 Flows
   • 2.7 Tokens and buckets
   • 2.8 Packets and frames

3. Traditional Elements of Traffic Control

   • 3.1 Shaping
   • 3.2 Scheduling
   • 3.3 Classifying
   • 3.4 Policing
   • 3.5 Dropping
   • 3.6 Marking

4. Components of Linux Traffic Control

   • 4.1 qdisc
   • 4.2 class
   • 4.3 filter
   • 4.4 classifier
   • 4.5 policer
   • 4.6 drop
   • 4.7 handle

5. Software and Tools

   • 5.1 Kernel requirements
   • 5.2 iproute2 tools (tc)
   • 5.3 tcng, Traffic Control Next Generation
   • 5.4 IMQ, Intermediate Queuing device

6. Classless Queuing Disciplines (qdiscs)

   • 6.1 FIFO, First-In First-Out (pfifo and bfifo)
   • 6.2 pfifo_fast, the default Linux qdisc
   • 6.3 SFQ, Stochastic Fair Queuing
   • 6.4 ESFQ, Extended Stochastic Fair Queuing
   • 6.5 GRED, Generic Random Early Drop
   • 6.6 TBF, Token Bucket Filter

7. Classful Queuing Disciplines (qdiscs)

   • 7.1 HTB, Hierarchical Token Bucket
   • 7.2 HFSC, Hierarchical Fair Service Curve
   • 7.3 PRIO, priority scheduler
   • 7.4 CBQ, Class Based Queuing

8. Rules, Guidelines and Approaches

   • 8.1 General Rules of Linux Traffic Control
   • 8.2 Handling a link with a known bandwidth
   • 8.3 Handling a link with a variable (or unknown) bandwidth
   • 8.4 Sharing/splitting bandwidth based on flows
   • 8.5 Sharing/splitting bandwidth based on IP

9. Scripts for use with QoS/Traffic Control

   • 9.1 wondershaper
   • 9.2 ADSL Bandwidth HOWTO script (myshaper)
   • 9.3 htb.init
   • 9.4 tcng.init
   • 9.5 cbq.init

10. Diagram

    • 10.1 General diagram

11. Annotated Traffic Control Links