Opened 6 years ago
Last modified 18 months ago
#11209 new defect
ar71xx iw reports adhoc rx rate 1Mbps (throughput is higher)
Reported by: | Musti <musti@…> | Owned by: | developers |
---|---|---|---|
Priority: | normal | Milestone: | Barrier Breaker 14.07 |
Component: | packages | Version: | Trunk |
Keywords: | Cc: | nbd |
Description
Tested on wr741nd v4.3 r30919, iw dev wlan0-1 station dump, iw does not report the correct rx bitrate, it is always 1Mbps, although I have performed throughput tests with iperf that go up to 17Mbps in both directions.
Please note that this was tested in a multi SSID setup ap+ad-hoc, the issue was on ad-hoc interface, ap interface reports the correct bitrate only after significant traffic has been passed through.
Providing: wireless config file, iwconfgi output, station dump outputs for both wireless interfaces.
root@wr741nd-test:/# cat /etc/config/wireless config wifi-device radio0 option type mac80211 option channel 8 option macaddr f8:d1:11:37:b8:0c option hwmode 11ng option htmode HT20 list ht_capab SHORT-GI-20 list ht_capab SHORT-GI-40 list ht_capab RX-STBC1 list ht_capab DSSS_CCK-40 config wifi-iface option device radio0 option network mesh option mode ap option ssid open option encryption none config wifi-iface option device radio0 option network mesh option mode adhoc option ssid mesh option bssid 02:CA:FF:EE:BA:BE option encryption none root@wr741nd-test:/# iwconfig lo no wireless extensions. edge0 no wireless extensions. eth1 no wireless extensions. wlan0-1 IEEE 802.11bgn ESSID:"mesh" Mode:Ad-Hoc Frequency:2.447 GHz Cell: 02:CA:FF:EE:BA:BE Tx-Power=18 dBm RTS thr:off Fragment thr:off Encryption key:off Power Management:on wlan0 IEEE 802.11bgn Mode:Master Frequency:2.447 GHz Tx-Power=18 dBm RTS thr:off Fragment thr:off Power Management:on eth0 no wireless extensions. mon.wlan0 IEEE 802.11bgn Mode:Monitor Frequency:2.447 GHz Tx-Power=18 dBm RTS thr:off Fragment thr:off Power Management:on root@wr741nd-test:/# iw dev wlan0 station dump Station b8:8d:12:23:23:ba (on wlan0) inactive time: 20 ms rx bytes: 90488265 rx packets: 69139 tx bytes: 56742973 tx packets: 65074 tx retries: 442587 tx failed: 0 signal: -52 [-52] dBm signal avg: -49 [-50] dBm tx bitrate: 72.2 MBit/s MCS 7 short GI rx bitrate: 72.2 MBit/s MCS 7 short GI authorized: yes authenticated: yes preamble: short WMM/WME: yes MFP: no TDLS peer: no root@wr741nd-test:/# iw dev wlan0-1 station dump Station b6:48:7a:a1:ac:14 (on wlan0-1) inactive time: 90 ms rx bytes: 25218263 rx packets: 36782 tx bytes: 46461786 tx packets: 37776 tx retries: 2301 tx failed: 0 signal: -49 [-49] dBm signal avg: -47 [-47] dBm tx bitrate: 54.0 MBit/s rx bitrate: 1.0 MBit/s authorized: yes authenticated: yes preamble: long WMM/WME: yes MFP: no TDLS peer: no
Attachments (0)
Change History (2)
comment:1 Changed 4 years ago by jow
- Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07
comment:2 Changed 18 months ago by thx1111
This report has been open since 2012-04-01. It is ongoing still in 2016, with iw version 4.3 in openwrt, and iw version 4.7 in Arch. It is not just a problem with openwrt per se.
The problem is not always with the "receive" bitrate, but may instead be with the "transmit" bitrate. Also, the misreported rate is complementary between the access point and the station, where, for instance, iw at the station may report "rx bitrate: 1.0 MBit/s" while the access point reports "tx bitrate: 1.0 MBit/s", even though the actual access point to station channel rate is some much higher value.
I suspect that the cause may be some kind of failed interaction between iw and various wireless drivers. I have seen iw report the "correct" transmit and receive bitrates on some station hardware while the access point is still reporting "1.0 MBit/s" as the "tx bitrate".
In addition to the problem with the transmit and receive bitrate reports, I also see iw misreport the signal levels on occasion, such as "196 dBm". That suggests some kind of overflow in the conversion software.
I suppose that this bug should be treated as "Upstream".
Milestone Attitude Adjustment 12.09 deleted