Re: txqueuelen has wrong units; should be time

Eric Dumazet
2011-03-02T16:52:26Z

Le mercredi 02 mars 2011 à 17:41 +0100, Mikael Abrahamsson a écrit :
> On Tue, 1 Mar 2011, Stephen Hemminger wrote:
>
> > Also WRED is not default on faster links because it can't be done fast
> > enough.
>
> Before this propagates as some kind of truth. Cisco modern core routers
> have no problems doing WRED at wirespeed, the above statement is not true.
>

looking at cisco docs you provided
( <http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/12stbwr.html>
)
, it seems the WRED time limits (instead of bytes/packets limits) are
internaly converted to bytes/packets limits

quote :

When the queue limit threshold is specified in milliseconds, the number
of milliseconds is internally converted to bytes using the bandwidth
available for the class.

So it seems its only a facility provided, and queues are still managed
with bytes/packets limits...

WRED is able to prob drop a packet when this packet is enqueued. At time
of enqueue, we dont know yet the time of dequeue, unless bandwidth is
known.