4.8-Stable DummyNet

[Eugene Grosbein]

bigtruck at ownij.com wrote:
> 
> Hi.  We just opened a gaming center and have chosen to run a FreeBsd box for
> our firewall.  IPFW is configured at it's very basic running natd through rl0
> and allowing any to any connections from the lan to the outer world.  Natd
> controls access to the lan.
> 
> We have a 6.0 mb/s ADSL net connection for all the gaming clients to use,
> however if a gamer starts downloading a file, that file takes precendence and
> causes everyone's pings 'in-game' to sky rocket to unplayable levels.  I have
> done some reading on DummyNet which is attached at the hip with IPFW, however I
> have been unsuccessful in getting it to work properly.

First of all, you should shape traffic on LAN imho, it will give
you much more control over situation. Second, you should create two
dummynet pipes, one for incoming and one for outgoing traffic and
set 6.0Mbit/s for its bandwidth parameter.

Then, you can engage WF2Q feature of dummynet that is capable
of "fair allocation" of bandwidth between competitors.
You create two queues using 'mask src-ip 0xffffffff' for outgoing traffic
and 'mask dst-ip 0xffffffff' for incoming. And you divert all 
of LAN traffic going into queues. That may be quite good for you.

Furthermore, you can engage GRED for preventing excessive TCP
packet drops, but that should be next stage.

Eugene Grosbein