Hi ALL,
I'm doing the performance profiling of our WiFi module with iperf.
The module is based on Marvell 8686 chipset with Libertas driver.
A strange issue i encounterred is that even i changed to a higher bit
rate ,the result of iperf seems that the bandwidth/troughput is still
not changed.
Details are as follows:
1. First test with default Bit Rate -1Mb/s
# iwconfig
eth1 IEEE 802.11b/g ESSID:"dlink"
Mode:Managed Frequency:2.437 GHz Access Point: 00:24:01:25:18:8A
Bit Rate:1 Mb/s Tx-Power=13 dBm
Retry limit:8 RTS thr=2347 B Fragment thr=2346 B
Encryption key:off
Power Management:off
Link Quality=100/100 Signal level=-22 dBm Noise level=-93 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:125310
Tx excessive retries:1120 Invalid misc:2988 Missed beacon:0
#
# iperf -c 172.31.42.51 -i 5 -t 60
------------------------------------------------------------
Client connecting to 172.31.42.51, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 172.31.42.218 port 33228 connected with 172.31.42.51 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 5.0 sec 792 KBytes 1.30 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 5.0-10.0 sec 680 KBytes 1.11 Mbits/sec
……
The bandwidth tested out with iperf is around 1.1Mb/s.
2. Change to a higner Bit Rate (11Mb/s) and re-test
# iwconfig eth1 rate 11M fixed
# iwconfig
eth1 IEEE 802.11b/g ESSID:"dlink"
Mode:Managed Frequency:2.437 GHz Access Point: 00:24:01:25:18:8A
Bit Rate=11 Mb/s Tx-Power=13 dBm
Retry limit:8 RTS thr=2347 B Fragment thr=2346 B
Encryption key:off
Power Management:off
Link Quality=100/100 Signal level=-22 dBm Noise level=-94 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:125610
Tx excessive retries:1120 Invalid misc:2988 Missed beacon:0
# iperf -c 172.31.42.51 -i 5 -t 60
------------------------------------------------------------
Client connecting to 172.31.42.51, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 172.31.42.218 port 33229 connected with 172.31.42.51 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 5.0 sec 776 KBytes 1.27 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 5.0-10.0 sec 720 KBytes 1.18 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 10.0-15.0 sec 680 KBytes 1.11 Mbits/sec
The bandwidth tested out with iperf is still around 1.1Mb/s.
Why the bandwidth is not changed when bit rate is changed to 11Mb/s?
Any thing wrong?
Thanks
Regards
Dongas
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
