UDP reverse mode doesn't output sensible data

[GoogleCodeExporter]

What steps will reproduce the problem?
1. recompile the 3.0 code as published on the website
2. on the server run: iperf3 --server
3. on the client run: iperf3 -c <server ip> -V -R -u

What is the expected output? What do you see instead?
Expected: 10 seconds continous transfer from server to client

I always get only transfer for the first second:

[root@intratest132 ~]# iperf3 -c 172.16.1.133 -V -R -u
iperf version 3.0-RC5 (07 November 2013)
Linux intratest132.net.lan 3.4.51-1.i2n.i686.PAE #1 SMP Fri Jun 28 13:49:25 UTC 
2013 i686 i686 i386 GNU/Linux
Time: Tue, 19 Nov 2013 23:47:54 GMT
Connecting to host 172.16.1.133, port 5201
Reverse mode, remote host 172.16.1.133 is sending
      Cookie: intratest132.net.lan.1384904874.4978
[  4] local 172.16.1.132 port 50775 connected to 172.16.1.133 port 5201
Starting Test: protocol: UDP, 1 streams, 8192 byte blocks, omitting 0 seconds, 
10 second test
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  8.00 KBytes  65.5 Kbits/sec              
[  4]   1.00-2.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   2.00-3.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   3.00-4.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   4.00-5.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   5.00-6.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   6.00-7.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   7.00-8.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   8.00-9.00   sec  0.00 Bytes  0.00 bits/sec              
[  4]   9.00-10.00  sec  0.00 Bytes  0.00 bits/sec              
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bandwidth       Jitter    Lost/Total 
Datagrams
[  4]   0.00-10.00  sec  8.00 KBytes  6.55 Kbits/sec  34940.621 ms  0/1 (0%)
[  4] Sent 1 datagrams
CPU Utilization: local/receiver 99.6%, remote/sender 68.3%

iperf Done.

What version of the product are you using? On what operating system?
recompiled from the published 3.0.tar.gz
32bit linux without ipv6 on both machines.

Original issue reported on code.google.com by intra2...@googlemail.com on 19 Nov 2013 at 3:59

[GoogleCodeExporter]

Something 'not right with your set-up; works for me (on a pair of HP ProBook 
8470w running Ubuntu 12.04, patched with 'send-to-self'; connected back-to-back 
via the motherboard ethernet port).

 ./iperf3 -c 192.168.3.5 -V -R -u
iperf version 3.0-RC5 (07 November 2013)
Linux HP-Lab1 3.2.51-send2self #1 SMP Tue Nov 12 11:45:32 GMT 2013 x86_64 
x86_64 x86_64 GNU/Linux
Time: Fri, 22 Nov 2013 00:12:57 GMT
Connecting to host 192.168.3.5, port 5201
Reverse mode, remote host 192.168.3.5 is sending
      Cookie: HP-Lab1.1385079177.043596.3265039e3e
[  4] local 192.168.3.1 port 52838 connected to 192.168.3.5 port 5201
Starting Test: protocol: UDP, 1 streams, 8192 byte blocks, omitting 0 seconds, 
10 second test
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec   136 KBytes  1.11 Mbits/sec
[  4]   1.00-2.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   2.00-3.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   3.00-4.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   4.00-5.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   5.00-6.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   6.00-7.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   7.00-8.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   8.00-9.00   sec   128 KBytes  1.05 Mbits/sec
[  4]   9.00-10.00  sec   128 KBytes  1.05 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bandwidth       Jitter    Lost/Total 
Datagrams
[  4]   0.00-10.00  sec  1.26 MBytes  1.06 Mbits/sec  0.011 ms  0/161 (0%)
[  4] Sent 161 datagrams
CPU Utilization: local/receiver 99.3%, remote/sender 14.4%

iperf Done.

Original comment by CharlesA...@gmail.com on 22 Nov 2013 at 12:20

[GoogleCodeExporter]

I've gotten this in TCP mode too, when using a -b bandwidth throttle. UDP uses 
a throttle by default, so I'm guessing the problem is in the throttling/timer 
code, probably on the server side, and not UDP related.  Will look into it.

Original comment by jef.posk...@gmail.com on 25 Nov 2013 at 7:11

[GoogleCodeExporter]

Original comment by jef.posk...@gmail.com on 26 Nov 2013 at 11:15

• Changed state: Fixed