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Topic: 80% UDP datagrams lost on a wrt54g with openwrt with iperf

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Post #1
lolo
1 Nov 2004, 21:40

on wrt54g v1.1 with a barebone openwrt +
libpthread_0.1_mipsel.ipk
libstdc++_5.0.5_mipsel.ipk
iperf_1.7.0-wrt1_mipsel.ipk

(package from www.wildcatwireless.net)

on the wrt :

/etc/init.d # iperf -s -f m -l 1470 -i 1 -p 5001 -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 0.03 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.1 port 5001 connected with 192.168.1.2 port 42551
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total Datagrams
[  3]  0.0- 1.0 sec  1.02 MBytes  8.57 Mbits/sec  1.223 ms 3007/ 3736 (80%)
[  3]  1.0- 2.0 sec  1.06 MBytes  8.93 Mbits/sec  1.817 ms 3265/ 4024 (81%)
[  3]  2.0- 3.0 sec  1.08 MBytes  9.07 Mbits/sec  1.448 ms 3164/ 3935 (80%)
[  3]  3.0- 4.0 sec  1.03 MBytes  8.67 Mbits/sec  1.258 ms 3163/ 3900 (81%)
[  3]  4.0- 5.0 sec  1.03 MBytes  8.67 Mbits/sec  1.172 ms 3251/ 3988 (82%)
[  3]  5.0- 6.0 sec  1.00 MBytes  8.37 Mbits/sec  1.243 ms 3181/ 3893 (82%)
[  3]  6.0- 7.0 sec  1.04 MBytes  8.73 Mbits/sec  1.024 ms 3162/ 3904 (81%)
[  3]  7.0- 8.0 sec  1.06 MBytes  8.87 Mbits/sec  1.194 ms 3099/ 3853 (80%)
[  3]  8.0- 9.0 sec  1.06 MBytes  8.93 Mbits/sec  0.883 ms 3168/ 3927 (81%)
[  3]  9.0-10.0 sec  1.09 MBytes  9.13 Mbits/sec  1.590 ms 3113/ 3889 (80%)
[  3]  0.0-10.2 sec  10.5 MBytes  8.59 Mbits/sec  15.529 ms 31638/39115 (81%)

on a debian 2.6.8 :

vaio:/home/vaio/wrt54g/packages-backup/www.wildcatwireless.net/wrt54g# iperf -c 192.168.1.1 -T 32 -i 1 -l 1470 -t 10 -p 5001 -f m -u -b54m
------------------------------------------------------------
Client connecting to 192.168.1.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 0.11 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.2 port 42551 connected with 192.168.1.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3] -0.0- 1.0 sec  5.43 MBytes  45.5 Mbits/sec
[  3]  1.0- 2.0 sec  5.51 MBytes  46.2 Mbits/sec
[  3]  2.0- 3.0 sec  5.48 MBytes  46.0 Mbits/sec
[  3]  3.0- 4.0 sec  5.52 MBytes  46.3 Mbits/sec
[  3]  4.0- 5.0 sec  5.51 MBytes  46.3 Mbits/sec
[  3]  5.0- 6.0 sec  5.47 MBytes  45.9 Mbits/sec
[  3]  6.0- 7.0 sec  5.46 MBytes  45.8 Mbits/sec
[  3]  7.0- 8.0 sec  5.46 MBytes  45.8 Mbits/sec
[  3]  8.0- 9.0 sec  5.49 MBytes  46.0 Mbits/sec
[  3]  9.0-10.0 sec  5.51 MBytes  46.2 Mbits/sec
[  3]  0.0-10.0 sec  54.8 MBytes  46.0 Mbits/sec
[  3] Server Report:
[  3]  0.0-10.2 sec  10.5 MBytes  8.59 Mbits/sec  15.528 ms 31638/39115 (81%)
[  3] Sent 39115 datagrams

wrt proc utilisation : 

/etc/init.d # ps aux
  PID  Uid     VmSize Stat Command
    1 0           380 S   init
    2 0               SW  [keventd]
    3 0               SWN [ksoftirqd_CPU0]
    4 0               SW  [kswapd]
    5 0               SW  [bdflush]
    6 0               SW  [kupdated]
    7 0               SW  [mtdblockd]
   16 0               SWN [jffs2_gcd_mtd4]
   30 0           344 S   syslogd -C 16
  553 0           376 S   /usr/sbin/dnsmasq
  558 0           376 S   /usr/sbin/httpd -p 80 -h /www -r WRT54G Router
  563 0           308 S   /usr/sbin/telnetd -l /bin/sh
  571 0           544 S   /bin/sh
 2550 0           356 R   ps aux
/etc/init.d #

lot of packet lost
more test needed

Post #2
lolo
3 Nov 2004, 10:28

A - LAN connection (bridge activated br0=eth0+eth2)
192.168.1.1=wrt54g
192.168.1.2=debian 2.6.8

1- pc=>wrt
on the pc side (client=sender)

vaio:/home/vaio# iperf -c 192.168.1.1 -T 32 -i 1 -l 1470 -t 10 -p 5001 -f m -u -b54m
------------------------------------------------------------
Client connecting to 192.168.1.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 0.11 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.2 port 32831 connected with 192.168.1.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3] -0.0- 1.0 sec  6.29 MBytes  52.8 Mbits/sec

[  3]  1.0- 2.0 sec  6.28 MBytes  52.7 Mbits/sec
[  3]  2.0- 3.0 sec  6.28 MBytes  52.7 Mbits/sec
[  3]  3.0- 4.0 sec  6.27 MBytes  52.6 Mbits/sec
[  3]  4.0- 5.0 sec  6.39 MBytes  53.6 Mbits/sec
[  3]  5.0- 6.0 sec  6.39 MBytes  53.6 Mbits/sec
[  3]  6.0- 7.0 sec  6.25 MBytes  52.4 Mbits/sec
[  3]  7.0- 8.0 sec  6.36 MBytes  53.4 Mbits/sec
[  3]  8.0- 9.0 sec  6.36 MBytes  53.4 Mbits/sec
[  3]  9.0-10.0 sec  6.36 MBytes  53.4 Mbits/sec
[  3]  0.0-10.0 sec  63.2 MBytes  53.0 Mbits/sec
[  3] Server Report:
[  3]  0.0-10.2 sec  14.1 MBytes  11.5 Mbits/sec  14.490 ms 35079/45107 (78%)
[  3] Sent 45

on the wrt side (server=receiver)

/etc # iperf -s -f m -l 1470 -i 1 -p 5001 -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 0.03 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.1 port 5001 connected with 192.168.1.2 port 32831
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total Datagrams
[  3]  0.0- 1.0 sec  1.45 MBytes  12.2 Mbits/sec  1.424 ms 3444/ 4480 (77%)
[  3]  1.0- 2.0 sec  1.44 MBytes  12.1 Mbits/sec  1.371 ms 3459/ 4486 (77%)
[  3]  2.0- 3.0 sec  1.39 MBytes  11.7 Mbits/sec  1.224 ms 3454/ 4446 (78%)
[  3]  3.0- 4.0 sec  1.44 MBytes  12.1 Mbits/sec  1.447 ms 3491/ 4518 (77%)
[  3]  4.0- 5.0 sec  1.38 MBytes  11.6 Mbits/sec  0.651 ms 3513/ 4496 (78%)
[  3]  5.0- 6.0 sec  1.38 MBytes  11.6 Mbits/sec  1.136 ms 3607/ 4591 (79%)
[  3]  6.0- 7.0 sec  1.40 MBytes  11.7 Mbits/sec  2.081 ms 3485/ 4482 (78%)
[  3]  7.0- 8.0 sec  1.43 MBytes  12.0 Mbits/sec  0.823 ms 3505/ 4528 (77%)
[  3]  8.0- 9.0 sec  1.37 MBytes  11.5 Mbits/sec  0.617 ms 3572/ 4546 (79%)
[  3]  9.0-10.0 sec  1.38 MBytes  11.6 Mbits/sec  0.594 ms 3474/ 4458 (78%)
[  3]  0.0-10.2 sec  14.1 MBytes  11.5 Mbits/sec  14.491 ms 35079/45107 (78%)
107 datagrams

2 - wrt=>pc
on the wrt side (client)

/etc #  iperf -c 192.168.1.2 -T 32 -i 1 -l 1470 -t 10 -p 5001 -f m -u -b54m
------------------------------------------------------------
Client connecting to 192.168.1.2, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 0.03 MByte (default)
------------------------------------------------------------
[  5] local 192.168.1.1 port 2049 connected with 192.168.1.2 port 5001
[ ID] Interval       Transfer     Bandwidth
[  5] -0.0- 1.0 sec  2.12 MBytes  17.7 Mbits/sec
[  5]  1.0- 2.0 sec  2.15 MBytes  18.0 Mbits/sec
[  5]  2.0- 3.0 sec  2.13 MBytes  17.9 Mbits/sec
[  5]  3.0- 4.0 sec  2.11 MBytes  17.7 Mbits/sec
[  5]  4.0- 5.0 sec  2.13 MBytes  17.9 Mbits/sec
[  5]  5.0- 6.0 sec  2.14 MBytes  17.9 Mbits/sec
[  5]  6.0- 7.0 sec  2.13 MBytes  17.9 Mbits/sec
[  5]  7.0- 8.0 sec  2.12 MBytes  17.8 Mbits/sec
[  5]  8.0- 9.0 sec  2.12 MBytes  17.8 Mbits/sec
[  5]  9.0-10.0 sec  2.11 MBytes  17.7 Mbits/sec
[  5]  0.0-10.0 sec  21.3 MBytes  17.8 Mbits/sec
[  5] Server Report:
[  5]  0.0-10.0 sec  21.1 MBytes  17.7 Mbits/sec  1.606 ms   76/15162 (0.5%)
[  5] Sent 15162 datagrams

on the pc side (server)

vaio:/home/vaio# iperf -s -f m -l 1470 -i 1 -p 5001 -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 0.11 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.2 port 5001 connected with 192.168.1.1 port 2049
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total Datagrams
[  3]  0.0- 1.0 sec  2.09 MBytes  17.5 Mbits/sec  0.043 ms   17/ 1509 (1.1%)
[  3]  1.0- 2.0 sec  2.14 MBytes  17.9 Mbits/sec  0.027 ms    9/ 1534 (0.59%)
[  3]  2.0- 3.0 sec  2.13 MBytes  17.9 Mbits/sec  0.036 ms    0/ 1520 (0%)
[  3]  3.0- 4.0 sec  2.11 MBytes  17.7 Mbits/sec  0.013 ms    0/ 1503 (0%)
[  3]  4.0- 5.0 sec  2.13 MBytes  17.9 Mbits/sec  0.042 ms    0/ 1522 (0%)
[  3]  5.0- 6.0 sec  2.14 MBytes  17.9 Mbits/sec  0.015 ms    0/ 1523 (0%)
[  3]  6.0- 7.0 sec  2.13 MBytes  17.9 Mbits/sec  0.110 ms    0/ 1519 (0%)
[  3]  7.0- 8.0 sec  2.09 MBytes  17.5 Mbits/sec  0.013 ms   27/ 1515 (1.8%)
[  3]  8.0- 9.0 sec  2.09 MBytes  17.5 Mbits/sec  0.013 ms   23/ 1514 (1.5%)
[  3]  9.0-10.0 sec  2.11 MBytes  17.7 Mbits/sec  0.011 ms    0/ 1502 (0%)
[  3]  0.0-10.0 sec  21.1 MBytes  17.7 Mbits/sec  1.607 ms   76/15162 (0.5%)

B - WLAN connection (bridge activated br0=eth0+eth2)
192.168.1.1=wrt54g
192.168.1.224=debian 2.6.8

1- pc=>wrt

on the pc side (client)

vaio:/home/vaio# iperf -c 192.168.1.1 -T 32 -i 1 -l 1470 -t 10 -p 5001 -f m -u -b54m
------------------------------------------------------------
Client connecting to 192.168.1.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 0.11 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.224 port 32831 connected with 192.168.1.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3] -0.0- 1.0 sec  3.16 MBytes  26.5 Mbits/sec
[  3]  1.0- 2.0 sec  3.29 MBytes  27.6 Mbits/sec
[  3]  2.0- 3.0 sec  3.21 MBytes  27.0 Mbits/sec
[  3]  3.0- 4.0 sec  3.27 MBytes  27.4 Mbits/sec
[  3]  4.0- 5.0 sec  3.25 MBytes  27.2 Mbits/sec
[  3]  5.0- 6.0 sec  3.28 MBytes  27.5 Mbits/sec
[  3]  6.0- 7.0 sec  3.22 MBytes  27.0 Mbits/sec
[  3]  7.0- 8.0 sec  3.28 MBytes  27.5 Mbits/sec
[  3]  8.0- 9.0 sec  3.22 MBytes  27.0 Mbits/sec
[  3]  9.0-10.0 sec  3.23 MBytes  27.1 Mbits/sec
[  3]  0.0-10.0 sec  32.4 MBytes  27.2 Mbits/sec
[  3] Server Report:
[  3]  0.0-10.2 sec  12.8 MBytes  10.5 Mbits/sec  12.091 ms 13998/23122 (61%)
[  3]  0.0-10.2 sec  2 datagrams received out-of-order
[  3] Sent 23122 datagrams

on the wrt side (server)

/ # iperf -s -f m -l 1470 -i 1 -p 5001 -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 0.03 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.1 port 5001 connected with 192.168.1.224 port 32831
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total Datagrams
[  3]  0.0- 1.0 sec  1.28 MBytes  10.7 Mbits/sec  2.311 ms 1221/ 2135 (57%)
[  3]  0.0- 1.0 sec  1 datagrams received out-of-order
[  3]  1.0- 2.0 sec  1.26 MBytes  10.5 Mbits/sec  1.905 ms 1436/ 2332 (62%)
[  3]  2.0- 3.0 sec  1.28 MBytes  10.8 Mbits/sec  2.009 ms 1398/ 2313 (60%)
[  3]  3.0- 4.0 sec  1.29 MBytes  10.8 Mbits/sec  1.656 ms 1417/ 2337 (61%)
[  3]  4.0- 5.0 sec  1.28 MBytes  10.8 Mbits/sec  1.580 ms 1383/ 2298 (60%)
[  3]  5.0- 6.0 sec  1.27 MBytes  10.6 Mbits/sec  1.436 ms 1438/ 2342 (61%)
[  3]  5.0- 6.0 sec  1 datagrams received out-of-order
[  3]  6.0- 7.0 sec  1.27 MBytes  10.7 Mbits/sec  1.223 ms 1408/ 2315 (61%)
[  3]  7.0- 8.0 sec  1.27 MBytes  10.7 Mbits/sec  1.805 ms 1407/ 2316 (61%)
[  3]  8.0- 9.0 sec  1.28 MBytes  10.7 Mbits/sec  2.291 ms 1401/ 2314 (61%)
[  3]  9.0-10.0 sec  1.28 MBytes  10.7 Mbits/sec  1.708 ms 1415/ 2328 (61%)
[  3]  0.0-10.2 sec  12.8 MBytes  10.5 Mbits/sec  12.091 ms 13998/23122 (61%)
[  3]  0.0-10.2 sec  2 datagrams received out-of-order

2- wrt=>pc
on the wrt side (client)

/ # iperf -c 192.168.1.224 -T 32 -i 1 -l 1470 -t 10 -p 5001 -f m -u -b54m
------------------------------------------------------------
Client connecting to 192.168.1.224, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 0.03 MByte (default)
------------------------------------------------------------
[  5] local 192.168.1.1 port 2049 connected with 192.168.1.224 port 5001
[ ID] Interval       Transfer     Bandwidth
[  5] -0.0- 1.0 sec  1.90 MBytes  16.0 Mbits/sec
[  5]  1.0- 2.0 sec  1.89 MBytes  15.8 Mbits/sec
[  5]  2.0- 3.0 sec  1.89 MBytes  15.9 Mbits/sec
[  5]  3.0- 4.0 sec  1.89 MBytes  15.9 Mbits/sec
[  5]  4.0- 5.0 sec  1.90 MBytes  15.9 Mbits/sec
[  5]  5.0- 6.0 sec  1.90 MBytes  15.9 Mbits/sec
[  5]  6.0- 7.0 sec  1.90 MBytes  15.9 Mbits/sec
[  5]  7.0- 8.0 sec  1.86 MBytes  15.6 Mbits/sec
[  5]  8.0- 9.0 sec  1.90 MBytes  15.9 Mbits/sec
[  5]  9.0-10.0 sec  1.89 MBytes  15.9 Mbits/sec
[  5]  0.0-10.0 sec  18.9 MBytes  15.9 Mbits/sec
[  5] Server Report:
[  5]  0.0-10.0 sec  18.6 MBytes  15.6 Mbits/sec  2.131 ms  238/13500 (1.8%)
[  5]  0.0-10.0 sec  6 datagrams received out-of-order
[  5] Sent 13500 datagrams

on the pc side (server)

vaio:/home/vaio# iperf -s -f m -l 1470 -i 1 -p 5001 -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 0.11 MByte (default)
------------------------------------------------------------
[  3] local 192.168.1.224 port 5001 connected with 192.168.1.1 port 2049
[ ID] Interval       Transfer     Bandwidth       Jitter   Lost/Total Datagrams
[  3]  0.0- 1.0 sec  1.76 MBytes  14.7 Mbits/sec  0.320 ms  105/ 1357 (7.7%)
[  3]  1.0- 2.0 sec  1.88 MBytes  15.8 Mbits/sec  0.039 ms    4/ 1347 (0.3%)
[  3]  2.0- 3.0 sec  1.86 MBytes  15.6 Mbits/sec  0.166 ms   19/ 1349 (1.4%)
[  3]  2.0- 3.0 sec  1 datagrams received out-of-order
[  3]  3.0- 4.0 sec  1.87 MBytes  15.7 Mbits/sec  0.027 ms   19/ 1351 (1.4%)
[  3]  4.0- 5.0 sec  1.89 MBytes  15.8 Mbits/sec  0.023 ms    8/ 1353 (0.59%)
[  3]  4.0- 5.0 sec  2 datagrams received out-of-order
[  3]  5.0- 6.0 sec  1.88 MBytes  15.7 Mbits/sec  0.124 ms   17/ 1355 (1.3%)
[  3]  5.0- 6.0 sec  1 datagrams received out-of-order
[  3]  6.0- 7.0 sec  1.88 MBytes  15.7 Mbits/sec  0.064 ms   17/ 1356 (1.3%)
[  3]  6.0- 7.0 sec  1 datagrams received out-of-order
[  3]  7.0- 8.0 sec  1.84 MBytes  15.4 Mbits/sec  0.042 ms   18/ 1329 (1.4%)
[  3]  8.0- 9.0 sec  1.86 MBytes  15.6 Mbits/sec  0.035 ms   19/ 1348 (1.4%)
[  3]  9.0-10.0 sec  1.87 MBytes  15.7 Mbits/sec  0.042 ms   12/ 1348 (0.89%)
[  3]  9.0-10.0 sec  1 datagrams received out-of-order
[  3]  0.0-10.0 sec  18.6 MBytes  15.6 Mbits/sec  2.131 ms  238/13500 (1.8%)
[  3]  0.0-10.0 sec  6 datagrams received out-of-order

What appears is the that wrt max out to about 11Mbits/s when receiving(server mode). That explain the high packet loss in both lan/wlan tests because the pc succede in sending at top rate (~54Mbit/s LAN & ~27Mbits/s WLAN)

In client mode(sending) the wrt max out at ~18Mbit/s on LAN test and ~16Mbit/s on WLAN test. There is no packet loss whith LAN connection (PC is potentially capable of receiving ~100Mbit/s) althought the packet  loss become visible on WLAN test (~1%) but seems ok : both side are talking at the same speed.

First conclusions/questions :
The bridge has maybe to be disable in order to get full 100Mbit/s on LAN interface
Why is the wrt maxing out at 11Mbit/s when receiving and 18Mbit/s when sending ? (wl/wl0_gmode=1)

Any hints/linkz/comments/advices ?

Post #3
Blackvel
3 Nov 2004, 10:31

Correct me if I am wrong but I think you can not start iperf on WRT because you would get wrong performance results.

Since the iperf program uses the CPU, etc.

Post #4
lolo
4 Nov 2004, 00:42

sure ! but dropping to a poor ~10Mbit/s for a 100Mbit/s LAN switch is a bit disappointing, even for a 125 MHZ proc doing some measurement : there are surely out there reasons explaning those anomalies

The discussion might have continued from here.