Stef, I solved my problem by changing PSCHED_CLOCK_SOURCE to PSCHED_CPU in /usr/src/linux/include/net/pkt_sched.h My graph is now a nice smooth diagonal line as I increase the bandwidth in increments as I did before. Thanks for you help on this one. You site has been a tremendous help in getting me up and running. Take care, Dan Farino Sr. System Engineer Stamps.com, Inc. Santa Monica, CA -----Original Message----- From: Stef Coene [mailto:stef.coene@docum.org] Sent: Tuesday, November 12, 2002 10:07 AM To: Dan Farino; lartc@mailman.ds9a.nl Subject: Re: Extremely inaccurate results using either TBF or HTB On Tuesday 12 November 2002 17:58, Dan Farino wrote: > Hi Stef, > > Thanks for the reply! However, I think the gap is way too large to be > explained by overhead, etc. > > Here are the results from some other tests. I started with: > tc qdisc add dev eth2 root tbf rate 1.9mbit buffer 20Kb/8 limit 15Kb > > Here are the average transfer rates measured over approx 20 seconds > (again according to PerfMon) as I change the "1.9mbit" to other values > while performing a large download: > > Mbit Kb/s > ----- ------ > 2.5 360 > 2.0 360 > 1.9 360 > 1.8 240 > 1.5 240 > 1.4 240 > 1.3 180 > 1.2 180 > > The lines really are that flat. There is nothing resembling the graphs > on your site. Mine has the low-res, stair-step effect that you can see > by graphing the above numbers. > > I can't seem to find any "mbit" number that will actually produce a cap > at exactly 2mbit. > > I will try a both different type NIC and Debian at some point today. What NIC are you using ? > Thanks for your help! No problem. I can send you my scripts that I use the record the bandwidth usage. Some of them can be found on www.docum.org. Basically, I create a iptables chain for each traffic stream I want to monitor. I record the counters each second and calculates the bandwdith. I have some scripts that executes a htb script, starts the needed flows, calculates the bandwidth, if the bandwidth is stable : record the bandwidth, restart the proces with a different setting. After some time, you have it for each rate so you can create a nice graph. Stef -- stef.coene@docum.org "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.oftc.net _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
