From owner-freebsd-mips@FreeBSD.ORG Tue Nov 23 15:31:00 2010 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 18C7A106566B for ; Tue, 23 Nov 2010 15:31:00 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9A33D8FC0A for ; Tue, 23 Nov 2010 15:30:59 +0000 (UTC) Received: by wye20 with SMTP id 20so352777wye.13 for ; Tue, 23 Nov 2010 07:30:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=TVvfQpaSgfAB+apI9xw43Kha/8VDC+bDa/uNO0jYiBw=; b=iGt7K5iGUR7FBwhYvGJx8yFXNg/cbTNDC7gC0Q64uWc/yIJDvj4NSNdtDAlY5Xzend ucJDuokOwT3gZE7KqMsotoZk3oV9dvd16FNGpvKTXBT0AnKeAmvF5lujACi1DprCUz6y A7avJuA9UNuJWY2eT0wlVwgXoEsZCeVTTza0g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=uqmZoA1rB8YUwdotxrBjB7+EqWEvLGF1k39XXO6c0gmvV0t1Ozsghhwqm8z7fwFnSG qzqq9E3qTyr0GL+tbKG/fPSVVdVfTP5Ni1y4tzYSLue+/FDw9+sWfrl/hyoxMUXAmMQ5 FsOj+frf2wEH6xCDcBY5IprzyDVOLKa5V8QEw= MIME-Version: 1.0 Received: by 10.227.143.136 with SMTP id v8mr7787609wbu.90.1290526257336; Tue, 23 Nov 2010 07:30:57 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.216.65.210 with HTTP; Tue, 23 Nov 2010 07:30:57 -0800 (PST) In-Reply-To: References: Date: Tue, 23 Nov 2010 23:30:57 +0800 X-Google-Sender-Auth: Ve6jr9vw-8D_QbUn3sTCMQB0qmk Message-ID: From: Adrian Chadd To: Larry Vaden Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-mips@freebsd.org Subject: Re: does anyone have a recommendation for a solid FreeBSD-based 802.11b/g/n AP package for MIPS-based APs and CPEs? X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Nov 2010 15:31:00 -0000 On 23 November 2010 23:18, Larry Vaden wrote: > Adrian, the reason for my original post (seeking to return to the BSD > environs) is that we are seeing gross quantities of stuck beacons in > dmesg on the Ubiquiti M series and have recently noted perps diagnosed > by the UBTik (a MikroTik in a housing form fit and function compatible > with the Rocket M2) trying to associate with _WDS requested_ resulting > in latencies of 10x-20x normal latency. =A0We don't run WDS on our 2.4 > GHz APs. =A0We only run WDS on Ubiquiti M5 series in PTP because that's > the way they produce a transparent Layer 2 bridge. > > Is the amount of time spent processing such a request, combined with > logging and a busy channel, perhaps enough to effectively cause a > denial of service? I've no idea. I haven't at all looked at WDS. As Sam likely pointed out, stuck beacons can include: * because the RF environment is somehow hilariously bad, congested or dirty (seen this); * because the code needing to setup the beacon frames, flush it to RAM before the TBTT (and related) timers fire just doesn't get a chance to run (seen this); * because your backend PCI bus/CPU/FSB bus/etc is busy, and thus the beacon frame doesn't go out in time (haven't seen this); * because the chip is being fondled in the wrong way somehow and it's locking up something (definitely seen this.) It's just a shame that people focus on "stuck beacon!" rather than trying to figure out what other events are occuring at the same time. :-) To track down stuck beacons at my wireless contract, I ended up doing a -lot- of instrumentation to try and figure out what was going on when stuck beacons occured. For example, stuck beacons were occuring in the deep past because the initial noise floor calibrations were being done every 1/10th of a second during a periodic calibration (every 20 minutes), rather than every few seconds, and this tended to upset the radio. Adrian