From owner-freebsd-net@FreeBSD.ORG Thu Sep 3 19:00:01 2009 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DD60A106566C for ; Thu, 3 Sep 2009 19:00:00 +0000 (UTC) (envelope-from sinister@gmail.com) Received: from mail-yw0-f187.google.com (mail-yw0-f187.google.com [209.85.211.187]) by mx1.freebsd.org (Postfix) with ESMTP id 7A9D38FC15 for ; Thu, 3 Sep 2009 19:00:00 +0000 (UTC) Received: by ywh17 with SMTP id 17so302903ywh.3 for ; Thu, 03 Sep 2009 11:59:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:from:to:cc :references:subject:date:mime-version:content-type :content-transfer-encoding:x-priority:x-msmail-priority:x-mailer :x-mimeole; bh=WKwt9jAB+YCYrfxAk5MMgdvjO1Vy7cq19ula7+NjFTs=; b=OWHwaIVO4x/pIg/3J3KtXRNpWG7/iJWMcxdG6d7CwsFa6UgG9U9QAByAdRY2SZDjaD 8PB/oSwi84AwSJ+4x1tZAVA52ZDyjReLls0w7wJL8V+ERBHrlVhNMPMHZUvaSKQr9T4l jh3zS3dzhuU0d86rDX60o/HJ/JQpky+vyhd5I= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:cc:references:subject:date:mime-version :content-type:content-transfer-encoding:x-priority:x-msmail-priority :x-mailer:x-mimeole; b=VSFz+y4qIMlo0Qf3666R22dFrq/wohR5VoO/uVz66WVwadYTZgoBRc8wcrqatbbnp6 Z4YCm6n3+5OB5W9kCEWFiJeTjYPFVyDPnFFXK2/5ZPjTDihBTi3saVRw3oAt73scYMOP CYudbribl0f0DCauLh3GOeyy2qDEsbjjWwhz4= Received: by 10.91.20.12 with SMTP id x12mr214198agi.19.1252004399355; Thu, 03 Sep 2009 11:59:59 -0700 (PDT) Received: from dts (markofthebeast.ca [216.8.139.47]) by mx.google.com with ESMTPS id 17sm462151agd.66.2009.09.03.11.59.55 (version=SSLv3 cipher=RC4-MD5); Thu, 03 Sep 2009 11:59:57 -0700 (PDT) Message-ID: From: Sin To: "Sam Leffler" , "Sin" References: <4790A7EF670C4698ADB76933788A218F@dts> <4A9E8C68.3060300@errno.com> <4AA0051F.8080202@errno.com> Date: Thu, 3 Sep 2009 14:59:59 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Cc: freebsd-net@freebsd.org Subject: Re: toggle short / long preamble with hostapd X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Sep 2009 19:00:01 -0000 Sam, You understand correctly. I should of mentioned also before with high latency comes packet loss, around 15 %. Setting short preamble makes this 1 % or less. So you are right - this doesn't make sense. If I've read this correctly, short preamble is enabled. So I do the ping tests from each machine including the AP and latency is back to under 2ms. test# ifconfig ath0 list sta ADDR AID CHAN RATE RSSI IDLE TXSEQ RXSEQ CAPS FLAG 00:18:de:22:13:f1 1 10 36M 29.5 0 146 34480 EPS AE WPA 00:18:39:15:c6:24 2 10 48M 36.0 0 140 32160 EPS AE WPA I was using channel 1 before in the first email because it was free ( found it free with ifconfig ath0 up scan ) I'm wondering if just changing to channel 10 was the real fix. I wll take your advice and move everything to 8.0. Having the option in any version to force preamble mode would be a nice feature. ----- Original Message ----- From: "Sam Leffler" To: "Sin" Cc: Sent: Thursday, September 03, 2009 2:04 PM Subject: Re: toggle short / long preamble with hostapd > If I understand correctly you say that you have stations associated to a > FreeBSD 7 ap operating in 11g and pings between the clients are slow. This > occurred w/ the Dlink AP you're trying to replace until you manually > forced short preamble. If I've got it right then this doesn't make sense > as the ap should be using short preamble unless there are non-ERP stations > on the channel. You can trace the status of short/long preamble with: > > wlandebug +assoc > > (you should get console msgs that when stations associate that indicate > whether protection is enabled). I believe you'll also get the same info > with: > > ifconfig wlan0 list sta > > on the ap. All this applies to 8.x; I've long since forgotten how things > work on 7.x and I'd recommend that if you're doing a new install you use > 8.0 and not 7.x. > > In general forcing short preamble should not have the effect you describe; > just the opposite. If you want to figure out what's really going on then > try to turn off stations that might be interfering (if possible). > Otherwise you might try moving to a different channel to avoid whatever > station is interfering. Another possibility is one or both stations are > in power save mode and there's a bug in the RELENG_7 ap support; wlandebug > +power might help for that. > > I can look at adding a knob to force short/long preamble. It would go > into HEAD though and can't promise to backport to RELENG_7. > > Sam > > Sin wrote: >> Sam, >> >> Basically I have a dlink WBR-1310 thats in bridge mode connected to my >> current BSD router ( 6.3) I'm trying to replace this 1310 product with >> FreeBSD 7. The last problem i'm dealing with is poor preformance. >> When I use my current BSD 7 setup it works, but ping times from client to >> another or even to the access point are bad. 100 - 400ms round trip. >> I had this exact problem with the 1310. The fix was to change from long >> to short preable. Been fine ever since. >> >> I used three computers to prove this before emailing. Just swapping the >> 1310 for the 7-STABLE corrects this. The 1310 uses g only mode with >> short preamble getting less then 5ms ping times to each client and host >> and vice-versa >> >> I realize that hostapd.conf is just for the encryption. However ifconfig >> and ath man pages do not talk about this setting. >> >> >> ----- Original Message ----- From: "Sam Leffler" >> To: "Sin" >> Cc: >> Sent: Wednesday, September 02, 2009 11:16 AM >> Subject: Re: toggle short / long preamble with hostapd >> >> >>> Sin wrote: >>>> Hello, >>>> >>>> >>>> Does anyone know how to enable short preamble in 7-STABLE ? >>>> >>>> I'm using ath with hostapd in ap mode. It seems there was an option in >>>> hostapd.conf, but this is not in FreeBSD's >>>> /usr/share/examples/hostapd/hostapd.conf >>>> >>>> >>>> The missing hostapd.conf option was found in google: >>>> >>>> # Short Preamble >>>> # This parameter can be used to enable optional use of short preamble >>>> for >>>> # frames sent at 2 Mbps, 5.5 Mbps, and 11 Mbps to improve network >>>> performance. >>>> # This applies only to IEEE 802.11b-compatible networks and this should >>>> only be >>>> # enabled if the local hardware supports use of short preamble. If any >>>> of the >>>> # associated STAs do not support short preamble, use of short preamble >>>> will be >>>> # disabled (and enabled when such STAs disassociate) dynamically. >>>> # 0 = do not allow use of short preamble (default) >>>> # 1 = allow use of short preamble >>>> #preamble=1 >>>> >>>> >>>> my version of hostapd is " v0.5.10 " - I was not able to set this >>>> option >>> >>> On freebsd hostapd is _purely_ an authenticator; to configure 802.11 >>> parameters you use ifconfig. >>> >>>> >>>> >>>> hostapd.conf: >>>> >>>> interface=ath0 >>>> #preamble=1 >>>> debug=1 >>>> ctrl_interface=/var/run/hostapd >>>> ctrl_interface_group=wheel >>>> ssid=private >>>> wpa=1 >>>> wpa_passphrase=apassword >>>> wpa_key_mgmt=WPA-PSK >>>> wpa_pairwise=TKIP >>>> >>>> >>>> >>>> rc.conf: >>>> >>>> hostapd_enable="YES" >>>> ifconfig_ath0="mode 11g hidessid mediaopt hostap" >>>> >>>> >>>> >>>> ifconfig ath0: >>>> >>>> ath0: flags=8943 metric >>>> 0 mtu 1500 >>>> ether 00:17:9a:4c:e7:83 >>>> media: IEEE 802.11 Wireless Ethernet autoselect mode 11g >>>> >>>> status: associated >>>> ssid private channel 1 (2412 Mhz 11g) bssid 00:17:9a:4c:e7:83 >>>> authmode WPA privacy MIXED deftxkey 2 TKIP 2:128-bit TKIP >>>> 3:128-bit >>>> txpower 31.5 scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 >>>> roam:rssi11g 7 roam:rate11g 5 protmode CTS burst hidessid >>>> dtimperiod 1 >>> >>> In ap mode you should not manually configure preamble; it should be >>> selected according to the associated stations. What are you trying to >>> accomplish? >>> >>> Sam >>> >> >> > >