1 Traffic control

     2 

     3 Classless pfifo_fast

     4 -------------

     5 3 bands. This means three fifos. 0 prioritized over 1, 1 over 2.

     6 The kernel puts the packets into the fifos according to TOS.

     7 classless

     8 

     9 Classless Tocken Bucket Filter (tbf)

    10 --------------

    11 limit: max number of bytes waiting for tokens

    12 

    13 latency: max time the bytes may wait for tokens (sets limit)

    14 

    15 burst/buffer/maxburst: size of the bucket in bytes.

    16 

    17 mpu: minimal token usage for a packet

    18 

    19 rate: speedknob?

    20 

    21 peakrate: The peakrate can be used to specify how quickly the bucket is

    22 allowed to be depleted. If doing everything by the book, this is achieved by

    23 releasing a packet, and then wait just long enough, and release the next. We

    24 calculated our waits so we send just at peakrate.

    25 

    26 mtu/minburst: A higher peakrate is possible by sending out more packets per

    27 timertick, which effectively means that we create a second bucket!. To calculate the maximum possible peakrate, multiply the configured mtu by 100

    28 (or more correctly, HZ, which is 100 on Intel, 1024 on Alpha).

    29 

    30 Classless Stochastic Fairness Queueing

    31 -------------------------------

    32 perturb: Reconfigure hashing once this many seconds.

    33 

    34 

    35 HTB (Hierarchic Token Bucket)

    36 -------------------------------

    37 All packets go to the class 1:1

    38 tc qdisc add dev eth1 root handle 1: htb default 1

    39 

    40 The class:

    41 tc class add dev eth1 parent 1: classid 1:1 htb rate 20kbps ceil 20kbps 

    42 

    43 A SFQ qdisc for that rate limited class, so all connections get fair traffic

    44 tc qdisc add dev eth0 parent 1:1 handle 40: sfq perturb 10