Re: HTB - What's the minimal value for 'rate' parameter?

[Antonio Almeida <vexwek@gmail.com>]

Now I understand. It makes sense - totally! Thanks for your endurance
trying to open my eyes :)
I've been trying rates bigger that 100bit for a while and it's working fine.
Thanks a lot for your illustration!

Regards
  Antonio Almeida



On Wed, Apr 14, 2010 at 10:45 PM, Jarek Poplawski wrote:
> Antonio Almeida wrote, On 04/14/2010 12:22 PM:
>
>> What do you mean with "1:2 has grandchildren with overflown rate tables"?
>> I couldn't understand your idea. Is there any mistake in the
>> configuration I sent?
>> How would you set rates for this particular example?
>
>
> class htb 1:1 root rate 1000Mbit ceil 1000Mbit
> class htb 1:2 parent 1:1 rate 4096Kbit ceil 4096Kbit
> class htb 1:10 parent 1:2 rate 1024Kbit ceil 4096Kbit
> class htb 1:11 parent 1:2 rate 1024Kbit ceil 4096Kbit
> class htb 1:101 parent 1:10 prio 3 rate 8bit ceil 4096Kbit
> class htb 1:111 parent 1:11 prio 3 rate 8bit ceil 4096Kbit
>
> Classes 1:101 and 1:111 have too low rates, which causes wrong (overflowed!)
> values in their rate tables, so their rates could be practically
> uncontrollable. They are limited by their ceils instead, so something like:
>
> class htb 1:101 parent 1:10 leaf 101: prio 3 rate 4096Kbit ceil 4096Kbit
> class htb 1:111 parent 1:11 leaf 111: prio 3 rate 4096Kbit ceil 4096Kbit
>
> But then their guaranteed rates are higher than their parents, and the
> sum is higher than grandparent's rate, which means the config is wrong.
> (You have to control these sums - HTB doesn't.)
>
> As I wrote before, the minimal (overflow safe) rate depends on max
> packet size, and for 1500 byte it would be something around:
> 1500b/2min, so if your clients can wait so long, try this:
>
> class htb 1:101 parent 1:10 leaf 101: prio 3 rate 100bit ceil 4096Kbit
> class htb 1:111 parent 1:11 leaf 111: prio 3 rate 100bit ceil 4096Kbit
>
> Regards,
> Jarek P.
>