[LARTC] priorities + htb

[LARTC] priorities + htb

[Abraham van der Merwe]

Hi!

How does prioritization work when you've got a tree structure, e.g.

 |
 +-- class_a rate 64kbit prio 1
 |    |
 |    +-- class_a1 rate 32kbit prio 1
 |    | 
 |    `-- class_a2 rate 32kbit prio 2
 |
 `-- class_b rate 64kbit prio 2

Above could either be interpreted as

 (a) a, a1 have prio 1
     b, a2 have prio 2

     (iow, no distinction is being made between the inner/nested classes and
      the outer/parent classes)

 OR

 (b) all packets matching a1, a2 are prio 1, then a1 is given a higher
     priority than a2

     (iow, multiple layers of prioritization exist)	 

-- 

Regards
 Abraham

TODAY the Pond!
TOMORROW the World!
                -- Frogs (1972)

___________________________________________________
 Abraham vd Merwe - Frogfoot Networks CC
 1st Floor, Albion Springs, 183 Main Road, Newlands
 Phone: +27 21 689 3876 Cell: +27 82 565 4451
 Http: http://www.frogfoot.net/ Email: abz@frogfoot.net

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Re: [LARTC] priorities + htb

[Ed Wildgoose]

Abraham van der Merwe wrote:

>Hi!
>
>How does prioritization work when you've got a tree structure, e.g.
>
>  
>

I think the whole idea of linux QOS is that it dequeues up the tree 
until it reaches the net interface.  So effectively I think you evaluate 
each leaf in turn on the way up the tree

If for example you have some queue which gives 50:50, and below one leaf 
you add another queue which gives 50:50 then I think those bottom leaves 
are getting 1/4 each.

I'm sure Andy or someone else will correct me if I'm wrong, but I think 
this is how you evaluate the whole QOS tree to see what will happen?

Ed W
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Re: [LARTC] priorities + htb

[pljosh]

U¿ytkownik Abraham van der Merwe napisa³:
> Hi!
> How does prioritization work when you've got a tree structure, e.g.
>  |
>  +-- class_a rate 64kbit prio 1
>  |    |
>  |    +-- class_a1 rate 32kbit prio 1
>  |    | 
>  |    `-- class_a2 rate 32kbit prio 2
>  |
>  `-- class_b rate 64kbit prio 2

HTB means: __Hierarchical__ Token Bucket so it is more like this:

>  (b) all packets matching a1, a2 are prio 1, then a1 is given a higher
>      priority than a2
> 
>      (iow, multiple layers of prioritization exist)	 
> 

But "prio" is used when there is some some unused BW that could be 
splited for borrowing (for classes which have ceil higher than rate).
-josh

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Re: [LARTC] priorities + htb

[Stef Coene]

On Friday 18 June 2004 13:12, pljosh wrote:
> U¿ytkownik Abraham van der Merwe napisa³:
> > Hi!
> > How does prioritization work when you've got a tree structure, e.g.
> >
> >  +-- class_a rate 64kbit prio 1
> >
> >  |    +-- class_a1 rate 32kbit prio 1
> >  |
> >  |    `-- class_a2 rate 32kbit prio 2
> >
> >  `-- class_b rate 64kbit prio 2
The prio of class class_a is never used and does not matter.

> HTB means: __Hierarchical__ Token Bucket so it is more like this:
> >  (b) all packets matching a1, a2 are prio 1, then a1 is given a higher
> >      priority than a2
> >
> >      (iow, multiple layers of prioritization exist)
>
> But "prio" is used when there is some some unused BW that could be
> splited for borrowing (for classes which have ceil higher than rate).
Htb is used for 2 things:
- class with lowest prio will get the lowest latancy (if and only if this 
class is not sending more data then the tate)
- class will lowest prio will get the remaining bandwidth from the parent 
after each child class is sending his rate.

Stef

-- 
stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
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