Hello,

I'm trying to setup Linux wireless router. I'm using hostapd with DWA-547 to setup wireless access point. The performance of DWA-547 is really very poor. The card actually performs better in 802.11g mode which doesn't make any sense. 802.11n mode with channel width 20/40MHz slows down the whole system, even ssh becomes glitchy (text input lags). top shows 90-98% idle. Signal strength is 81%. I'm using channel 9 everybody else in visible range is using channel 1.

Does anyone else experience performance slow down in 802.11n mode and/or knows the cause of this?


SeedTest.net and 20 pings to router when idle results:

DWA-547 802.11g
down 20.81 Mb/s
up 20.16 Mb/s
Minimum = 0ms, Maximum = 2ms, Average = 0ms

DWA-547 802.11n channel width 20 MHz
down 16.22 Mb/s
up 13.72 Mb/s
Minimum = 0ms, Maximum = 3ms, Average = 1ms

DWA-547 802.11n channel width 20/40 MHz
down 3.48 Mb/s
up 1.76 Mb/s
Minimum = 13ms, Maximum = 207ms, Average = 57ms

Just for reference DIR-655 results
DIR-655 802.11n channel width 20 MHz
down 66.51 Mb/s
up 39.57 Mb/s
Minimum = 0ms, Maximum = 2ms, Average = 0ms


System:
OS: Linux ipfire 2.6.32.15-ipfire #1 SMP Tue Jun 29 21:04:08 GMT 2010 i686 athlon-4 i386 GNU/Linux
Compat-wireless 2.6.34
AMD Athlon (don't remember actual numbers but the clock is above 1GHZ)
512MB RAM
DLink DWA-547(atheros chipset) wireless PCI card
2x Realtek LAN card

hostapd.conf:

same problem here. i have an ubuntu 10.10 x64 desktop setup as a router, ap, nas, htpc.
over wired network it works well, achieves maximum speed that it's provided by ISP.

But when i try to copy files drom NAS over wireless, or stream movies the ubuntu pc can't be used, text imput and mouse start to lag. maximum throughput on laptop in wireless n mode 2MB/s with an 4965AGN intel wifi card. with a wireless router i got 8-10MB/s with this intel card, with speedtest.net i get max 1mbps download instead of 3mbps (just over wireless, wired works).

i tryed several kernels,stoc hostapd 0.61(max throughput 700-800k over network), and then hostapd 0.73(2MB/s lan-wireless copy)

config:
wireless card: tplink TL-WN951N ar5008 3tx3r
ubuntu x64 10.10 kernel 2.6.35-24-generic
mb gigabyte g41mft-us2h
celeron dual core E3200
2gb ddr3 dual ch
1tb wd black
hosapd 0.7.3


tryed many hosapd config's siple an complex this workt best 'till now


hostapd conf:

interface=wlan1
driver=nl80211
#bridge=br0

country_code=RO
hw_mode=g
channel=6
ieee80211n=1
ssid=Ubuntu_AP
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0
#beacon_int=100
#dtim_period=2
ignore_broadcast_ssid=0

macaddr_acl=1
accept_mac_file=/etc/hostapd/accept

#wpa=2
#wpa_key_mgmt=WPA-PSK
#wpa_pairwise=TKIP CCMP
#wpa_passphrase=12345678

ht_capab=[HT40+][SHORT-GI-40][LDPC][GF][DELAYED-BA][DSSS_CCK-40][MAX-AMSDU-7935][TX-STBC][RX-STBC123]
wmm_enabled=1

# Low priority / AC_BK = background
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0

# Normal priority / AC_BE = best effort
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0

# High priority / AC_VI = video
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0

# Highest priority / AC_VO = voice
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0