If memory serves me right, Michael Fox wrote: > The iperf3 bandwidth option doesn't seem to work (or perhaps I'm not using > it correctly). > > iPerf3 version 3.1.3 on Ubuntu server and Windows client. > > I'm trying to test radio links at various bandwidths, ranging from 32 Kbps > to 400 Kbps, and various packet sizes, ranging from 256 to 1520 bytes. But > setting the bandwidth down to the link bandwidth (or lower) doesn't slow the > output from the client. > > Example: In the example below, bandwidth is clearly set at 128K, but > resulting bandwidth in 200K. > > How do I get the iperf client to only send at the specified rate?
I think the #1 thing you should try is to get newer executables of iperf3. Starting with iperf-3.2 (3.5 is current now) we re-tuned a bunch of stuff with how the transmitter side paces stuff (or rather we made it so it isn't so horribly broken). The use cases where this really helps is for UDP, which tended to send packets in huge bursts, and also had difficulty sending at very low bitrates as you are doing. (iperf3 was originally designed for high-speed environments, such as multiple-10Gbps.) If this doesn't work, sending smaller packets might help, although I think controlling the packet size is part of your tests, so that might not be feasible. Bruce. >> iperf3 -c 192.168.8.10 -u -l 1472 -b 128K > Connecting to host 192.168.8.10, port 5201 > [ 4] local 192.168.7.147 port 59396 connected to 192.168.8.10 port 5201 > [ ID] Interval Transfer Bandwidth Total Datagrams > [ 4] 0.00-1.00 sec 25.9 KBytes 212 Kbits/sec 18 > [ 4] 1.00-2.00 sec 24.4 KBytes 200 Kbits/sec 17 > [ 4] 2.00-3.00 sec 24.4 KBytes 200 Kbits/sec 17 > [ 4] 3.00-4.00 sec 25.9 KBytes 212 Kbits/sec 18 > [ 4] 4.00-5.00 sec 21.6 KBytes 177 Kbits/sec 15 > [ 4] 5.00-6.00 sec 24.4 KBytes 200 Kbits/sec 17 > [ 4] 6.00-7.00 sec 21.6 KBytes 176 Kbits/sec 15 > [ 4] 7.00-8.00 sec 24.4 KBytes 200 Kbits/sec 17 > [ 4] 8.00-9.00 sec 23.0 KBytes 189 Kbits/sec 16 > [ 4] 9.00-10.00 sec 23.0 KBytes 188 Kbits/sec 16 > - - - - - - - - - - - - - - - - - - - - - - - - - > [ ID] Interval Transfer Bandwidth Jitter Lost/Total > Datagrams > [ 4] 0.00-10.00 sec 239 KBytes 195 Kbits/sec 0.049 ms 0/165 (0%) > [ 4] Sent 165 datagrams > > iperf Done. > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Iperf-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/iperf-users >
signature.asc
Description: OpenPGP digital signature
------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________ Iperf-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/iperf-users
