[LARTC] burst question

[Stef Coene]

On Thursday 18 November 2004 19:27, richard lucassen wrote:
> This is one of my test classes:
>
> class htb 1:10 parent 1:1 prio 0 quantum 2048 rate 160Kbit ceil 400Kbit
> burst 1803b/8 mpu 0b cburst 2111b/8 mpu 0b level 0
>
> Q1: where does "level 0" stand for?
=46rom /usr/src/linux-2.6.8/net/sched/sch_htb.c
    Levels:
    Each class is assigned level. Leaf has ALWAYS level 0 and root
    classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level
    one less than their parent.

> Q2: where does this b/8 stand for?
Don't know.

> Q3: this is on a i386 platform, so timer resolution should be 10mS.
> According to the doc the minimal burst should be 10mS*160Kbit=3D1600. Why
> is it 1803?
=46rom /usr/src/iproute2/tc/q_htb.c
        /* compute minimal allowed burst from rate; mtu is added here to ma=
ke
           sute that buffer is larger than mtu and to have some safeguard=20
space */

> Q4: I want this class to be able to allow 400Kbit burst during 3
> seconds. What value should I give to the burst parameter? Is this
> 400/160*1803=3D4507b?
400kbit * 3s =3D 1200kbit.
You can try this, but htb burst is not made for this.  It is made for burst=
 of=20
a few k.

Stef

=2D-=20
stef.coene@docum.org
=A0"Using Linux as bandwidth manager"
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