[LARTC] Borrowing between HTB classes not working as expectd.

[Ryan Castellucci]

On 11/13/05, andreas.klauer at metamorpher.de
<andreas.klauer at metamorpher.de> wrote:
> Quoting Ryan Castellucci <ryan.castellucci at gmail.com>:
> > I did not mix these up. I'm using the 1:2 class for TCP and ICMP
> > control packets, such as TCP acks which need an amount of bandwidth
> > proportinate to the maximum download rate.
>
> There seems to be a misunderstanding of some kind. You say you're using
> the 1:2
> class for control packets; but in the output you've sent, the 1:2 class is the
> root HTB class, so it should be (indirectly) used for everything.

Erp, I ment 1:3.....

> The only
> classes you can use directly (that means classify packets to) are the leaf
> classes (HTB classes which don't have any more children), in your setup that
> would be one of the 1:3,356-361,612-617,869-873 leaf classes.
>
> Class 1:2 has a rate/ceil of 217kbit. Children of this class are 1:3
> (124/149),
> 1:4 (128/243), 1:5 (102/243), and 1:6 (25/204). As I said before, the problem
> is that the rates of these classes don't add up. These child classes added
> together for example use 124+128+102+25=379kbit, although the parent provides
> only 217kbit. Classes 1:4 and 1:5 in particular can borrow up to 243kbit each,
> although the parent class can provide only 217kbit in total. So how exactly do
> you expect the borrowing to work? Unless you have an understanding of
> the inner
> workings of HTB in great detail, the results of this setup are pretty much
> unpredictable.
>
> The same problem can be found further down the tree; for example, the
> class 1:4
> has a rate of 128kbit. Children of this class are 1:356-361, with a rate of
> 128kbit each. Added together, they require a rate of 768kbit, but the parent
> class only provides 128kbit (or it would if the parent class of this parent
> class could provide as much).
>
> Same story with 1:5 and 1:6.
>
> The first thing you have to do is calculate the class rates so they add up
> properly. Otherwise you will never get anywhere near a predictable borrowing
> behaviour.

I'll go though and make sure everything adds up, and try it again.

--
Ryan Castellucci http://ryanc.org/