Dummynet Queue Weighting

[Louis A. Mamakos]

> # SAMPLE CONFIG
> ipfw queue 1 ip from A to B
> ipfw queue 1 config weight 10 pipe 1
> ipfw queue 2 ip from C to D
> ipfw queue 2 config weight 5 pipe 1
> ipfw queue 3 ip from E to F
> ipfw queue 3 config weight 1 pipe 1
> ipfw pipe 1 config bw 1000Kbit/s
> 
> Question?
> 
> When setting up queues as I have done above with different weights they (the
> queues) will share the assigned pipe proportionate to their weight.
> 
> For example if you had traffic on all three queues, the A&B(1), C&D(2), and
> E&F(3); they would get 10/16, 5/16, and 1/16 of the pipe, respectively.
> 
> But, what if A&B(1) had no traffic? It is my understanding that queue 2 and
> 3 would still only get 5/16 and 1/16 of the pipe regardless. In this
> example, 3/8 or 375Kb/s total. Or would 2 and 3 share the whole pipe if
> queue 1 is inactive, which would make my questions moot?

I use a similar configuration to prioritize VoIP traffic on my
"upstream" network connection.  I create a pipe with the bandwidth
sized to the actual capacity of the network link and the multiple
queues just as you did.  

The answer to your question is that idle queue do not consume capacity
on the pipe they are associated with.  I have queue with weights
100 (for VoIP), 20 (for interactive SSH, NTP) and 1 (everything else)
and the "everything else" traffic can use the full capacity of the
pipe with the other queues are idle.

louie