Forwarding this to the list just so its in the archives. ---------- Forwarded message ---------- From: Jody Shumaker <jody.shumaker@xxxxxxxxx> Date: May 10, 2006 3:45 PM Subject: Re: HTB at 100+ Mbits/sec To: Muthukumar S <muthukumar@xxxxxxxxx>
3. I've never quite understood the recommendation for setting the root HTB to 85-90% of the link. All these tests used 100%. Can someone please explain or point me to some explanations for the 90% recommendation and why it is considered necessary?
85-90% is just a recommendation, in reality it just needs to be slightly lower than the actual max bandwidth. The reason for this is to insure you are the bottleneck. If you aren't the bottleneck, then it's likely there will a queue at the the other bottleneck that will diminish the value to any shaping you do. Often the 85-90% figure is given because people may be told by their isp they have 512kbit, but in reality it rarely performs that much due to noisy lines etc. Personally I'd suggest measuring the actual max bandwidth and then set the limit below that. In my case my isp claims i have 2mbit upload, in testing I found myself to have 1840.8kbit/s upload, and thus set my max to 1836kbit/s to give myself 5kbit/s of room in case noise varies and my actual upload max varies. compare to my isp's claimed 2mbit though, this is 91.8%. If I had just used the 90% guideline it would of been accurate. In the past though, I've been able to use 504kbit on a 512kbit connection because testing found it to consistently get a real throughput of around 508kbit. - Jody _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
