LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking > Linux - Wireless Networking
User Name
Password
Linux - Wireless Networking This forum is for the discussion of wireless networking in Linux.

Notices

Reply
 
Search this Thread
Old 07-11-2010, 03:56 AM   #1
zibalas
LQ Newbie
 
Registered: Jan 2010
Posts: 15

Rep: Reputation: 0
Question ath9k (AR5008) in AP mode - very poor performance


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:

Code:
driver=nl80211
######################### basic hostapd configuration ##########################
#
interface=blue0
channel=09
hw_mode=g
ieee80211n=1
logger_syslog=-1
logger_syslog_level=4
logger_stdout=-1
logger_stdout_level=4
dump_file=/tmp/hostapd.dump
auth_algs=1
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0
ssid=IPFire
ignore_broadcast_ssid=0
######################### wpa hostapd configuration ############################
#
wpa=2
wpa_passphrase=******
wpa_key_mgmt=WPA-PSK
wpa_pairwise=CCMP TKIP

#ht_capab=[HT40-]
 
Old 01-07-2011, 01:39 AM   #2
Beret_87
LQ Newbie
 
Registered: May 2005
Location: Romania
Posts: 5

Rep: Reputation: 0
same problem

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
 
  


Reply

Tags
80211n, ath9k, wireless


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] Master mode on AR928X using ath9k driver. Jophish Linux - Networking 1 10-26-2010 06:05 AM
poor performance javabb Red Hat 8 01-20-2005 05:48 AM
poor performance in x ah786 Slackware 10 11-09-2004 11:11 AM
Poor performance Shyne Red Hat 1 10-17-2004 11:50 AM
Poor Video Performance yoink Linux - Newbie 3 12-03-2002 12:07 PM


All times are GMT -5. The time now is 12:22 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration