Help? Where?
>From: "Richard Clark" <rclark --at-- airgain.com>
>To: <mitch --at-- dast.nlanr.net>
>Subject: Help? Where?
>Date: Wed, 7 Jul 2004 12:47:13 -0700
>
>
>Mitch,
>
>Sorry to bother you directly, but I cant seem to find a support contact
anywhere&
>Tried the support/contact page, but the comment line only takes, well, one
line.
>Tried the email link, but that doesnt work either (dast --at-- nlanr.net)...
>Hoping your address works! J
>
>Also tried to find anything about KNOWN PROBLEMS , but search doesnt work,
>and there is zilch in the iperf documentation&
>
>Heres the original text/problem&
>
>Hi!
>
>A customer of ours reported some throughput problems, which we
subsequently investigated, and found to be something odd in the iperf
testing tool. We
>are hoping you might have some answers/guidance for us.
>
>Namely, we are running testing between two WinXP machines, via the
>dos command prompt, using iperf u s i 5 and iperf u c
><ipaddr> -i 5 t 30 b 10m , through a pair of wireless Ethernet bridges.
>The results that we get using different packet sizes -l x are very
strange.
>For packet 1100 bytes or smaller, we get throughput about 6.2 mbits/sec.
>
>For packets 1200 to 1490 bytes, we get throughput of about 1.7mbits/sec.
>
>Yes, even the default UDP packet size of 1470 gets throughput of about
1.5mbits/sec.
>
>And for packets 1500 bytes or more, we again get throughput of 6.2 mbits/sec.
>
>We tried to reproduce this behavior with the Chariot testing tool, but
varying the
>UDP datagram sizes there did not have the same result. In other words,
Chariot gave
>about 6.2mbits throughput for all the above packet sizes&
>
>So, my question is, are there known problem/quirks with 1200-1490 byte
packets?
>
>Have you seen this problem before? Any clues/help you can give us?
>
>Thanks!!!
>
>Richard H. Clark
>Airgain, Inc.
>
>C:\IPERF>iperf -s -u -i 5 -l 1460
>------------------------------------------------------------
>Server listening on UDP port 5001
>Receiving 1460 byte datagrams
>UDP buffer size: 8.00 KByte (default)
>------------------------------------------------------------
>[1968] local 192.168.0.21 port 5001 connected with 192.168.0.190 port 1552
>[ ID] Interval Transfer Bandwidth Jitter Lost/Total
Datagrams
>[1968] 0.0- 5.0 sec 1.03 MBytes 1.72 Mbits/sec 8.992 ms 1302/ 2039 (64%)
>[1968] 5.0-10.0 sec 1.05 MBytes 1.76 Mbits/sec 9.008 ms 1400/ 2155 (65%)
>[1968] 10.0-15.0 sec 1.04 MBytes 1.74 Mbits/sec 5.347 ms 1387/ 2134 (65%)
>[1968] 15.0-20.0 sec 1.02 MBytes 1.71 Mbits/sec 7.762 ms 1393/ 2127 (65%)
>[1968] 20.0-25.0 sec 1.05 MBytes 1.76 Mbits/sec 5.505 ms 1402/ 2154 (65%)
>[1968] 25.0-30.0 sec 1.02 MBytes 1.72 Mbits/sec 11.355 ms 1384/ 2120 (65%)
>[1968] 0.0-30.3 sec 6.26 MBytes 1.74 Mbits/sec 12.375 ms 8347/12844 (65%)
>
--
Mitch Kutzko | mitch --at-- dast.nlanr.net | mitch --at-- ncsa.uiuc.edu | 217-333-1199
Project: http://dast.nlanr.net/ | Personal: http://hobbes.ncsa.uiuc.edu/