[altq:1884] ALTQ Performance Problem - help needed!

["Thorsten Kutska" <thorsten.kutska@student.uni-tuebingen.de>]

Hi everybody. I'm new to this group and I got the following problem. I hope
this isn't a repost but i couldn't find anything in the archives about that
topic.

I'm using ALTQ on a OpenBSD 3.3 ethernet bridge in a building that is
connected via a 3MBit connection to our ISP.
The box is a PIII-800, BX Chipset, with 128MB RAM and two 3Com ethernet
cards.
There are about 120 users in the house and I want to make a rather fair
queuing for everyone of them (guaranteed minimum bandwidth, borrow) and I'm
planning to prioritize some things in the future (empty tcp-acks).

I tried the following:

I wrote a script that looks which users are online and creates a pf.conf
according to the results. Each user gets one queue. The script is run every
minute, so the config file is reloaded every minute.

My pf.conf looks like this:

#######################
# ALTQ directives:
altq on $ext_if cbq bandwidth 3000Kb queue { q_def_out, q_users_out,
q_servers_out }
altq on $int_if cbq bandwidth 3000Kb queue { q_def_in, q_users_in,
q_servers_in }

# Static queues:
queue q_def_in bandwidth 10Kb cbq(default)
queue q_def_out bandwidth 10Kb cbq(default)
queue q_servers_in bandwidth 50Kb cbq
queue q_servers_out bandwidth 400Kb cbq

# Parent user queues (example for only one user. if more than one user is
online, the bandwidth gets divided equally among them)
queue q_users_in bandwidth 2940Kb cbq { q_076158_in }
queue q_users_out bandwidth 2590Kb cbq { q_076158_out }

# Example user queue:
queue q_076158_in bandwidth 2940Kb cbq(borrow)
queue q_076158_out bandwidth 2590Kb cbq(borrow)

pass out log quick on $ext_if from 172.16.76.158 to any queue q_076158_out
pass out log quick on $int_if from any to 172.16.76.158 queue q_076158_in
#######################

I managed to get it to work and it worked quite fine when only a few users
were online. But when I have like 30 users online, the maximum throughput
seems to go down to like 600KBits/s.

So I praise you, mighty ALTQ-gurus, if you got some ideas for improvements,
any help is appreciated very much.

Best regards

Thorsten Kutska

[I apologize if my english isn't correct, I'm german ;- ) ]