ipprecedence

Eugene Grosbein eugen at kuzbass.ru
Sun Jul 6 22:05:04 PDT 2003


> > > How could the scheduler decide when to drain the queue ?
> > It should move packets from zero-bw WFQ pipe the interface FIFO
> > as soon as possible but should consider weights
> with infinite bandwidth (that is what 'bw 0' means),
> "as soon as possible" means immediately, so you will
> never have anything in the dummynet queues, and weights
> would have no purpose.

Ok, I've got this. Perhaps, I need to setup 2bmit dummynet pipe.

> > Well, I could do that but my configuration is different.
> > My FreeBSD router does not have WaveLan interface. Instead, I have
> > another device (named "RWR") with one 10Mbit Ethernet interface
> > and one 2Mbit WaveLan interface. RWR can pass traffic with non-zero
> > IP Precedence first. FreeBSD has fxp(4) 100Mbit Ethernet card that
> > connects it to the RWR. So I see no reason to patch fxp(4) here :-)
> 
> so what's your problem then ???

Cisco3640<-ethernet/LAN1->FreeBSD<-ethernet->RWR1<-radio-
-radio>RWR2<-ethernet/LAN2>-ATA186

The first problem is that VoIP is delay-intolerate.
The second problem is that WaveLan is 2mbit only and is overloaded.
The other problem is that routers in the chain are loaded significantly.
So the goal is to make voice traffic prioritized over the whole
chain of routers.

Cisco can pass VoIP before other traffic ("ip rtp priority" command),
RWRs can too. Is FreeBSD capable of prioritizing VoIP in this scenario?
I hope it is. Perhaps, I need 2mbit dummynet queue for traffing that
goes to LAN2 (and back to LAN2) and different weights for VoIP
and other flows. Am I right?

Eugene Grosbein


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