4.8-Stable DummyNet

[Mike Porter]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Monday 02 June 2003 01:55 pm, 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.
>
> I have done some research and found this site:
> http://info.iet.unipi.it/~luigi/ip_dummynet/
>
> After reading I became more confused than before.  Should I share the link
> as a whole to all 64 client machines OR should I set a fixed BW for all
> client machines.  Are there other websites out there that can help with
> this?
>
> Also if and when I do find a working pipe/queue config do I put it before
> the natd via rl0 command or after?

Another consideration, from experience:  rl is not a very good "inside" nic, 
at least if running with the old standby 8139 chip.  I don't have direct 
experience with the 82xx family they are using these days, but with my 
8139-based card, I could never, under windows, get a single download past 
30KBps (but I could open 3 downloads before the performance started to fall 
off) (this is on a cable modem).  Under BSD (4-stable in the days of 4.5 and 
4.6) I couldn't get anything past 100Kbps.  Using a machine with two 
realtek's as a gateway/router, I found I was brealy better than dialup on my 
local machines.  Switching to a Netgear NIC (dc driver) vastly improved 
matters.  When set for dc0=outside, rl0=inside, my LAN performance is about 
the same (indicating a bottleneck in rl0), however, my WAN performance is 
about 1/3 better (I can consistently get 130KBps+, and frequently exceed 
200KBps; once in a while I can even get more than 300KBps, but due to the 
nature of cable, that is pretty rare.).  Putting dc0 on "inside" duty more 
than doubles the performance of my LAN, without changing any network 
infrastructure.  This tells me the rl8139 at least is optimized for use on 
asymetric connection, such as DSL or Cable, and is not really (even though it 
claims to support it) a full-duplex card.  Spend a few dollars more, and get 
a better card, in other words.

I guess that doesn't really help with dummynet, but it could explain some of 
the performance problem...

mike
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (FreeBSD)

iD8DBQE+3RSRY30jZzkECLcRAo/GAJwJyRZfadU1ISrfluktUN2s/JqinwCfdC1w
9ucO194yP4ccqgLW4eg30Aw=
=QTrN
-----END PGP SIGNATURE-----