ipprecedence

[Eugene Grosbein]

On Wed, Jul 02, 2003 at 09:18:48AM -0700, Luigi Rizzo wrote:

> > > It seems to me you could use dummynet/ipfw2 to provide a
> > > stronge PREFERENCE for packets w/non-zero precedence --
> ...
> > And what bandwidth of pipe should I use?
> > Note that I do not need traffic shaping,
> > I need to rearrange queues only.
> 
> Are you really sure that you are seeing significant queueing
> in your system ?

It seems so.

> Reordering packets based on precedence/priority
> typically makes sense at the bottleneck, not elsewhere.

My prioritized traffic is VoIP that is low volume but intolerate to delays.

> And your bottleneck is probably your ISP, not your local router.

This traffic originates, passes and terminates inside our
heterogeneous network completely.

> If, on the contrary, you have some kind of "slow" interface,
> such as various kinds of serial lines etc. you might in
> principle put a call to "if_tx_rdy()" in the 'transmit complete'
> interrupt service routine of the device driver, and put
> 
> 	pipe ... config bw foo0
> 
> where foo0 is the name of your device (I introduced this in
> 3.x times, though no device supports it).

Sadly, I really have slow media (overloaded 2Mbit WaveLan)
but it is served by standalone router (not bridge) that is capable
to rearrange packets using IP precedence. My FreeBSD is connected
using 10Mbit ethernet with that WaveLan router (that's name is Revolution)
and this 10Mbit segment is loaded too. So if FreeBSD could rearrange queues
using IP precedence, that would be pretty useful. Can it?

Eugene