From owner-freebsd-wireless@FreeBSD.ORG Thu Jul 18 15:59:30 2013 Return-Path: Delivered-To: freebsd-wireless@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id A5E276C6 for ; Thu, 18 Jul 2013 15:59:30 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-wi0-x22c.google.com (mail-wi0-x22c.google.com [IPv6:2a00:1450:400c:c05::22c]) by mx1.freebsd.org (Postfix) with ESMTP id 43F51810 for ; Thu, 18 Jul 2013 15:59:30 +0000 (UTC) Received: by mail-wi0-f172.google.com with SMTP id c10so6836199wiw.5 for ; Thu, 18 Jul 2013 08:59:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; bh=SAWavVkG+IpwN1GThQSHmwW1lwMapvyfobDPRlWeP7U=; b=XQbPxulFLA6TCxQPeOu592BCys5aUZwMDCSxKrnvGetS+aFWXKRIgoiJO6nkUxjAkv QQik2PdUmjBkEojRG+sqqgY/YiB2bmRdCEn7He4oNEsSQQKCPEjCTjpA4HiqWdepAesE ZKWPbHFDEADE9Xnm0QBCYtRu5/9T2AJwQGISWvj+NfuRk1QSiqUTKXdvypcXmpmsRXoV 1cwS4gZ9r60rqZnLOzucy4V2bjLb/sOnZJFuXZsdE8ojx5rzyQkeKvzinaUOd880hSG8 jA8U/hBqw6SUkS9t041Z4wKlKKeSCenVCYn9XalEkYvCKvlQ8gsCxQCwyz+pwKaRVCLe +HGw== MIME-Version: 1.0 X-Received: by 10.194.63.229 with SMTP id j5mr8865513wjs.79.1374163169453; Thu, 18 Jul 2013 08:59:29 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.217.94.132 with HTTP; Thu, 18 Jul 2013 08:59:29 -0700 (PDT) In-Reply-To: <20130718155200.GA381@pintail.NGC004> References: <20130718155200.GA381@pintail.NGC004> Date: Thu, 18 Jul 2013 08:59:29 -0700 X-Google-Sender-Auth: RQHLGv8LNCwxTbtXkNM9K2t6Je8 Message-ID: Subject: Re: high latency due to distant clients From: Adrian Chadd To: freebsd-wireless@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-BeenThere: freebsd-wireless@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Discussions of 802.11 stack, tools device driver development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Jul 2013 15:59:30 -0000 Hi, I think I fixed this in -HEAD. -adrian On 18 July 2013 08:52, Petar Bogdanovic wrote: > Hi, > > for several years now, I've been running an ALIX-AP with a CM9 Atheros > 5212 card. The AP covers a whole house which has about 6 flats and the > average amount of active clients ranges from 10 to 15. > > Recently I noticed high latency when pinging the AP itself which happens > when distant clients (who knows where around the house---could be inside > or outside) seem to cause "longs" (long on-chip tx retries) and/or > "xretries" (tx failed 'cuz too many retries). > > The Rate, when talking to these distant clients, is usually below 11M > (sometimes as low as 1M) which is consistent with their low RSSI values > the AP is reporting. > > With high latency I mean continuous bursts of 500-1000ms instead of > 0.5ms so I wonder if this is normal. > > The software is slightly out of date and athstats is not completely in > sync with the kernel i'm using (therefore its not reporting some values): > > # uname -a > FreeBSD parrot.NGC004 8.1-RC2 FreeBSD 8.1-RC2 #2: Thu Aug 16 21:13:54 CEST 2012 > > # athstats -i ath0 > athstats: ath0: Invalid argument > athstats: ath0: Invalid argument > 3181606 data frames transmit > 45659 tx frames with an alternate rate > 568149 long on-chip tx retries > 19091 tx failed 'cuz too many retries > 0M current transmit rate > 25 tx stopped 'cuz no xmit buffer > 20922 tx frames with no ack marked > 3039151 tx frames with short preamble > 362335 rx failed 'cuz of bad CRC > 1181 rx failed 'cuz of PHY err > 315 OFDM restart > 866 CCK restart > 2 TDMA slot timing updates > -0/+0 TDMA slot adjust (usecs, smoothed) > 26135 TDMA tx failed 'cuz ACK required > -74 rx noise floor > 3070927 tx frames through raw api > 6299685 fast frames received > 1328215 fast frames flushed from staging q > 20835 ANI decrease noise immunity > 6593 ANI increased spur immunity > 121582 ANI decrease spur immunity > 160 ANI decreased first step level > 2 cumulative OFDM phy error count > 2 RTS without CTS > 1360093 beacons received > Antenna profile: > > Any ideas on how to avoid that? Of course I could buy better antennas > but it seems that, generally speaking, this shouldn't happen. > > Thanks, > > Petar Bogdanovic > _______________________________________________ > freebsd-wireless@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-wireless > To unsubscribe, send any mail to "freebsd-wireless-unsubscribe@freebsd.org"