Curious if iperf2 <https://sourceforge.net/projects/iperf2/>exhibits
similar behavior? It shouldn't have an issue with low packet rates.
Bob
On Mon, Apr 16, 2018 at 2:25 PM, Bruce A. Mah <[email protected]> wrote:
> 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.
> >
> >
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>
>
>
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