[Codel] [PATCH 1/2] codel: Controlled Delay AQM

[Eric Dumazet]

On Mon, 2012-05-07 at 14:50 -0400, Jim Gettys wrote:

> You want to turn it on in CeroWrt: sure.  Expert audience, who may be
> able to notice when things go sour, fine....
> 
> Neither you, nor I are expert at the current state of ECN in the global
> Internet: but Steve Bauer is.  We can have that conversation with him
> shortly.
> 
> So for now "First, do no harm" should be our mantra....
> 
> So the upstream patch default state should be off.  We don't want to mix
> "codel doesn't work" with "ecn is busted someplace", as it gets its trials.
> 

ecn is negociated by peers, not a qdisc.

ecn at qdisc level is only marking an already enabled ECN packet.

Since most packets are not ECN enabled, they are dropped instead.

If you read my ECN addition to Codel, you can see its disabled by
default already. Its a toy for early adopters.