I've been testing DCCP using netem for quite a while now - just about always with loss and delay. This works really well. A few weeks ago I noticed that if netem isn't turned on but traffic still goes between boxes through a router the performance is abysmal - can be as low as 20K per second instead of 100 Mbit and there is much data loss. I had assumed that this was a recent regression so parked it until I had time to test. However I just tested with a clean 2.6.14 and the problem persists.... The test setup is 10.0.1.31 ----- 10.0.1.33/10.0.2.33 ------- 10.0.2.32 and the command is just: (from 10.0.1.31) ./ttcp_acme -c -l500 -n10000 -t 10.0.2.32 and (from 10.0.2.32) ./ttcp_acme -c -l500 -n10000 -r the following setup works fine: 10.0.1.31 ----- 10.0.1.33 ./ttcp_acme -c -l500 -n10000 -t 10.0.1.33 and ./ttcp_acme -c -l500 -n10000 -r I'll add this to my list of bugs to look at at some stage (along with updating tx buffering, CCID2 not working with loss/delay) but interested in seeing if others have similar problems? Ian -- Ian McDonald Web: http://wand.net.nz/~iam4 Blog: http://imcdnzl.blogspot.com WAND Network Research Group Department of Computer Science University of Waikato New Zealand - : send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
