Incorrect Throughput Summaries in UDP?
Hello,
We're trying to do some iperf tests through an uncongested network using UDP
streams, reporting the rate every 2 seconds for 1 minute. We're using iperf
1.6.5 with pthreads and we get some strange reporting of the summary result:
------------------------------------------------------------
Server listening on UDP port 5010
Receiving 1472 byte datagrams
UDP buffer size: 2097152 Byte (WARNING: requested 1048576 Byte)
------------------------------------------------------------
[ 3] local xxx.xxx.xxx.xxx port 5010 connected with
xxx.xxx.xxx.xxx port 32769
[ ID] Interval Transfer Bandwidth Jitter Lost/Total
Datagrams
[ 3] 0.0- 2.0 sec 204248832 Bytes 816993694 bits/sec 0.015 ms
41676/180432 (23%)
[ 3] 0.0- 2.0 sec 2 datagrams received out-of-order
[ 3] 2.0- 4.0 sec 200495232 Bytes 801980527 bits/sec 0.016 ms
45147/181353 (25%)
[ 3] 4.0- 6.0 sec 199322048 Bytes 797289787 bits/sec 0.011 ms
45986/181395 (25%)
[ 3] 6.0- 8.0 sec 199009984 Bytes 796037946 bits/sec 0.007 ms
46202/181399 (25%)
[ 3] 8.0-10.0 sec 199110080 Bytes 796411251 bits/sec 0.031 ms
46153/181418 (25%)
[ 3] 10.0-12.0 sec 199123328 Bytes 796523978 bits/sec 0.013 ms
46182/181456 (25%)
[ 3] 12.0-14.0 sec 199288192 Bytes 797152369 bits/sec 0.025 ms
46043/181429 (25%)
[ 3] 14.0-16.0 sec 199408896 Bytes 797552240 bits/sec 0.028 ms
46029/181497 (25%)
[ 3] 16.0-18.0 sec 199332352 Bytes 797412738 bits/sec 0.012 ms
46090/181506 (25%)
[ 3] 18.0-20.0 sec 196868224 Bytes 787472109 bits/sec 0.025 ms
47720/181462 (26%)
[ 3] 20.0-22.0 sec 194798592 Bytes 779195147 bits/sec 0.014 ms
49125/181461 (27%)
[ 3] 22.0-24.0 sec 194883968 Bytes 779420907 bits/sec 0.030 ms
49077/181471 (27%)
[ 3] 24.0-26.0 sec 194845696 Bytes 779424093 bits/sec 0.028 ms
49066/181434 (27%)
[ 3] 26.0-28.0 sec 194858944 Bytes 779509829 bits/sec 0.013 ms
49097/181474 (27%)
[ 3] 28.0-30.0 sec 195091520 Bytes 780318871 bits/sec 0.029 ms
48976/181511 (27%)
[ 3] 30.0-32.0 sec 194680832 Bytes 778715151 bits/sec 0.025 ms
49238/181494 (27%)
[ 3] 32.0-34.0 sec 196510528 Bytes 786080630 bits/sec 0.029 ms
47969/181468 (26%)
[ 3] 34.0-36.0 sec 199289664 Bytes 797175397 bits/sec 0.017 ms
46106/181493 (25%)
[ 3] 36.0-38.0 sec 199210176 Bytes 796770190 bits/sec 0.041 ms
46157/181490 (25%)
[ 3] 38.0-40.0 sec 199313216 Bytes 797323826 bits/sec 0.019 ms
46024/181427 (25%)
[ ID] Interval Transfer Bandwidth Jitter Lost/Total
Datagrams
[ 3] 40.0-42.0 sec 199375040 Bytes 797390917 bits/sec 0.028 ms
45999/181444 (25%)
[ 3] 42.0-44.0 sec 200144896 Bytes 800570377 bits/sec 0.029 ms
45466/181434 (25%)
[ 3] 44.0-46.0 sec 199370624 Bytes 797549490 bits/sec 0.022 ms
45984/181426 (25%)
[ 3] 46.0-48.0 sec 199458944 Bytes 797878462 bits/sec 0.030 ms
45885/181387 (25%)
[ 3] 48.0-50.0 sec 101038080 Bytes 404154543 bits/sec 0.026 ms
113310/181950 (62%)
[ 3] 50.0-52.0 sec 199441280 Bytes 797706887 bits/sec 0.021 ms
45894/181384 (25%)
[ 3] 52.0-54.0 sec 197998720 Bytes 792020621 bits/sec 0.025 ms
46817/181327 (26%)
[ 3] 54.0-56.0 sec 199107136 Bytes 796465181 bits/sec 0.013 ms
46163/181426 (25%)
[ 3] 56.0-58.0 sec 200219968 Bytes 800880673 bits/sec 0.022 ms
45416/181435 (25%)
[ 3] 58.0-60.0 sec 197239168 Bytes 788955489 bits/sec 0.012 ms
47441/181435 (26%)
[ 3] 0.0-60.0 sec 1559126656 Bytes 207849079 bits/sec 0.012 ms
1466661/5443627 (27%)
[ 3] 0.0-60.0 sec 2 datagrams received out-of-order
As you can see, the summary rate is much smaller than that reported by the
regular intervals; also, the total number of bytes transfered is about a third
less than the accumulated count.
We repeated the test a few times and the report is similar in all tests.
Any comments/suggestions appreciated!
Yee.
--
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Yee-Ting Li email: ytl --at-- hep.ucl.ac.uk
High Energy Particle Physics http://www.hep.ucl.ac.uk/~ytl
University College London Tel: +44 (0) 20 7679 1376
Gower Street Fax: +44 (0) 20 7679 7145
London, WC1E 6BT
United Kingdom
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