Re: how RED should work ?

Andy Furniss
Fri, 07 Dec 2007 12:50:32 -0000

Salatiel Filho wrote:
> Hi , i am trying to understand how RED queue discipline works but i am
> having a few troubles.
>
> The parameters are MIN , MAX , LIMIT , BURST
>
> I put LIMIT = 64Kb, so if i am not wrong it should PDROP anything over
> this value , right ?
> i put MIN  = 8Kb , so no drops at all below this value, right ?
> i put MAX = 16Kb, starts to early drop anything above this using
probability P.
> I put probability at 0.5 [very high , just for test]
> i PUT burst at 20 [actually , no idea what really put in here]
>
> but after a while downloading at full speed i still get no drops at
> all. Using 50% probability i should get at least 1 early drop shouldnt
> i ?
>
> qdisc red 3: limit 64Kb min 8Kb max 16Kb
>  Sent 5023410 bytes 3817 pkts (dropped 0, overlimits 0)
>   marked 0 early 0 pdrop 0 other 0
>
>
>

RED doesn''t rate limit by its self so you need to make it a child of
htb/tbf/hfsc.

Andy.