What I neglected to say is that TCP works fine and it is very low latency... On 3/9/06, Ian McDonald <imcdnzl@xxxxxxxxx> wrote: > 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 > -- 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
