From owner-freebsd-hardware@FreeBSD.ORG Sun Jan 14 11:52:11 2007 Return-Path: X-Original-To: freebsd-hardware@freebsd.org Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id ED51316A40F for ; Sun, 14 Jan 2007 11:52:11 +0000 (UTC) (envelope-from soralx@cydem.org) Received: from cydem.org (S0106000103ce4c9c.vc.shawcable.net [24.87.27.3]) by mx1.freebsd.org (Postfix) with ESMTP id D357013C455 for ; Sun, 14 Jan 2007 11:52:09 +0000 (UTC) (envelope-from soralx@cydem.org) Received: from soralx.cydem.org (unknown [192.168.0.249]) by cydem.org (Postfix/FreeBSD) with ESMTP id 1369391FAE; Sun, 14 Jan 2007 03:52:08 -0800 (PST) Date: Sun, 14 Jan 2007 03:52:06 -0800 From: To: Message-ID: <20070114035206.2089217d@soralx.cydem.org> In-Reply-To: <20070113121335.46975.qmail@web52714.mail.yahoo.com> References: <20070113121335.46975.qmail@web52714.mail.yahoo.com> X-Mailer: Claws Mail 2.6.1 (GTK+ 2.10.6; i386-portbld-freebsd5.4) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: trigves@yahoo.com Subject: Re: DWL-G520 low signal, low speed X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Jan 2007 11:52:12 -0000 > >>> I have a problem with my wifi DWL G520 atheros chip based card... > >>> I have low signal only 20-30% and also a low speed 5-11 > >>> Mbit/s..router is only 1-2 m away from me and with gentoo I have > >>> 90% signal strength..I'm using FreeBSD 6.2 PRERELEASE Same thing here, folks. When using the 'if_ath' module (or compiling the driver into kernel -- doesn't matter), the reported signal strength (via `ifconfig ath0 up && ifconfig ath0 scan`) is about 20:0 to 30:0 (whatever the units are?), depending on spatial orientation, and being positioned ~10m away from the base station. The 'media:' quickly degrades to 'DS/1Mbps'. Measurement of the signal strength with notebook relocated right near the transceiver yield values of 50-60 units (noise has the value of '0' all the time). Perhaps the ndisulator is being overly optimistic, but it reports S:N of ~140:0 when away from the transiever, and ~160:0 when near. ifconfig says that media is OFDM/54Mbps. I says that probably the units are totally arbitrary, or the ndis driver is just being piss-proud [i.e., exaggerating a little, and his signal is not really that big] ;) Now, I didn't do any real performance comparison yet (ath vs ndis), but I can say this: ath performance seems to me rather disappointing -- the carrier gets lost from time to time, range is not impressive (or am i just expecting too much?), there's absolutely no reception without antenna connected (I believe this isn't right), etc... I don't have much time to look into the issue now, but if someone will suggest how to do some advanced testing (at almost a step-by-step level), I would do that. OS: 6.2-BETA2 [SorAlx] ridin' VN1500-B2 From owner-freebsd-hardware@FreeBSD.ORG Sun Jan 14 14:28:41 2007 Return-Path: X-Original-To: freebsd-hardware@freebsd.org Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 1DBCF16A40F for ; Sun, 14 Jan 2007 14:28:41 +0000 (UTC) (envelope-from trigves@yahoo.com) Received: from web52714.mail.yahoo.com (web52714.mail.yahoo.com [206.190.48.237]) by mx1.freebsd.org (Postfix) with SMTP id D692C13C455 for ; Sun, 14 Jan 2007 14:28:38 +0000 (UTC) (envelope-from trigves@yahoo.com) Received: (qmail 13778 invoked by uid 60001); 14 Jan 2007 14:28:37 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type; b=h1ze3AS894EEtxuB0aINyCOHUNcGtrmhA2eYHO6OQq8srqG7rimiLTfhHozrDUr9x8uZpjoFO1kDFtosSnyQf+pKEXTP8d8LwO2D0xN+m/BsKZ8Quhtokmml8jPtWAQCoafLe9BwzvofHfR2B3GD+J/YlIGWisgKYs1BAfym64o= ; Message-ID: <20070114142837.13776.qmail@web52714.mail.yahoo.com> Received: from [195.168.231.73] by web52714.mail.yahoo.com via HTTP; Sun, 14 Jan 2007 06:28:37 PST Date: Sun, 14 Jan 2007 06:28:37 -0800 (PST) From: Trigve Siver To: freebsd-hardware@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Re: DWL-G520 low signal, low speed X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Jan 2007 14:28:41 -0000 Hi,=0A=0AOne more thing I want to add is...that when I was using ath I have= had low speed and also had a lot of interupts and I realised that ath was = sharing IRQ with USB (IRQ 19 in my case)... so I disabled the USB and throw= away ath from kernel and compile it as module (want to take some performan= ce test with ndis and ath)...and after that I have still low signal but med= ia is OFDM/54 Mbps and is stable... to the performance....I think that ndis= is somehow a little faster...when dowloading/uploading about 100 kB/s fast= er...but haven't done some serious testing (don't know how maybe with kisme= t?)=0A=0ATrigve=0A=0A----- Original Message ----=0AFrom: "soralx@cydem.org"= =0ATo: freebsd-hardware@freebsd.org=0ACc: trigves@yahoo.= com=0ASent: Sunday, January 14, 2007 12:52:06 PM=0ASubject: Re: DWL-G520 lo= w signal, low speed=0A=0A=0A> >>> I have a problem with my wifi DWL G520 at= heros chip based card...=0A> >>> I have low signal only 20-30% and also a l= ow speed 5-11=0A> >>> Mbit/s..router is only 1-2 m away from me and with ge= ntoo I have=0A> >>> 90% signal strength..I'm using FreeBSD 6.2 PRERELEASE= =0A=0ASame thing here, folks. When using the 'if_ath' module (or compiling = the=0Adriver into kernel -- doesn't matter), the reported signal strength= =0A(via `ifconfig ath0 up && ifconfig ath0 scan`) is about 20:0 to 30:0=0A(= whatever the units are?), depending on spatial orientation, and being=0Apos= itioned ~10m away from the base station. The 'media:' quickly=0Adegrades to= 'DS/1Mbps'. Measurement of the signal strength with notebook=0Arelocated r= ight near the transceiver yield values of 50-60 units (noise=0Ahas the valu= e of '0' all the time).=0A=0APerhaps the ndisulator is being overly optimis= tic, but it reports S:N=0Aof ~140:0 when away from the transiever, and ~160= :0 when near. ifconfig=0Asays that media is OFDM/54Mbps. I says that probab= ly the units are=0Atotally arbitrary, or the ndis driver is just being piss= -proud [i.e.,=0Aexaggerating a little, and his signal is not really that bi= g] ;)=0A=0ANow, I didn't do any real performance comparison yet (ath vs ndi= s), but=0AI can say this: ath performance seems to me rather disappointing = -- the=0Acarrier gets lost from time to time, range is not impressive (or a= m i=0Ajust expecting too much?), there's absolutely no reception without=0A= antenna connected (I believe this isn't right), etc...=0A=0AI don't have mu= ch time to look into the issue now, but if someone will=0Asuggest how to do= some advanced testing (at almost a step-by-step=0Alevel), I would do that.= =0A=0AOS: 6.2-BETA2=0A=0A[SorAlx] ridin' VN1500-B2=0A_____________________= __________________________=0Afreebsd-hardware@freebsd.org mailing list=0Aht= tp://lists.freebsd.org/mailman/listinfo/freebsd-hardware=0ATo unsubscribe, = send any mail to "freebsd-hardware-unsubscribe@freebsd.org"=0A=0A=0A=0A=0A= =0A=0A=0A=0A =0A___________________________________________________________= _________________________=0ANeed Mail bonding?=0AGo to the Yahoo! Mail Q&A = for great tips from Yahoo! Answers users.=0Ahttp://answers.yahoo.com/dir/?l= ink=3Dlist&sid=3D396546091 From owner-freebsd-hardware@FreeBSD.ORG Sun Jan 14 18:35:46 2007 Return-Path: X-Original-To: freebsd-hardware@freebsd.org Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D306216A4A0 for ; Sun, 14 Jan 2007 18:35:46 +0000 (UTC) (envelope-from sam@errno.com) Received: from ebb.errno.com (ebb.errno.com [69.12.149.25]) by mx1.freebsd.org (Postfix) with ESMTP id 86B1313C4BB for ; Sun, 14 Jan 2007 18:35:46 +0000 (UTC) (envelope-from sam@errno.com) Received: from [10.0.0.199] ([10.0.0.199]) (authenticated bits=0) by ebb.errno.com (8.13.6/8.12.6) with ESMTP id l0EIZeot025768 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 14 Jan 2007 10:35:40 -0800 (PST) (envelope-from sam@errno.com) Message-ID: <45AA77FC.8080702@errno.com> Date: Sun, 14 Jan 2007 10:35:40 -0800 From: Sam Leffler Organization: Errno Consulting User-Agent: Thunderbird 1.5.0.9 (Macintosh/20061207) MIME-Version: 1.0 To: soralx@cydem.org References: <20070113121335.46975.qmail@web52714.mail.yahoo.com> <20070114035206.2089217d@soralx.cydem.org> In-Reply-To: <20070114035206.2089217d@soralx.cydem.org> X-Enigmail-Version: 0.94.1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: trigves@yahoo.com, freebsd-hardware@freebsd.org Subject: Re: DWL-G520 low signal, low speed X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Jan 2007 18:35:46 -0000 soralx@cydem.org wrote: >>>>> I have a problem with my wifi DWL G520 atheros chip based card... >>>>> I have low signal only 20-30% and also a low speed 5-11 >>>>> Mbit/s..router is only 1-2 m away from me and with gentoo I have >>>>> 90% signal strength..I'm using FreeBSD 6.2 PRERELEASE > > Same thing here, folks. When using the 'if_ath' module (or compiling the > driver into kernel -- doesn't matter), the reported signal strength > (via `ifconfig ath0 up && ifconfig ath0 scan`) is about 20:0 to 30:0 > (whatever the units are?), depending on spatial orientation, and being > positioned ~10m away from the base station. The 'media:' quickly > degrades to 'DS/1Mbps'. Measurement of the signal strength with notebook > relocated right near the transceiver yield values of 50-60 units (noise > has the value of '0' all the time). Noise floor is not uniformly reported outside the driver, hence it is 0 according to the tools your using. Signal strength is the raw rssi coming off the card averaged over the last 10 frames. This is the receive signal strength in approximately 1/2 dBm units relative to the current noise floor. Correlating that to physical units is hard. About all you can do is consider that the rssi values coming out of the hardware are in the range 0..63. rssi values >~15 should support reasonable communication. Transmit speeds are mainly a property of the transmit rate control algorithm. You haven't indicated what you are using but presumably it is sample and it is known to be very sensitive to changes in rssi. That is a design flaw (maybe even a bug but noone seems to dig for these issues). Given an rssi of 20-30 I would expect to see upstream tcp netperf results through a reasonable AP on the order of 8-15 Mb/s to a station 1-hop past the ap. But that depends on many factors such as the ap and the antenna's. > > Perhaps the ndisulator is being overly optimistic, but it reports S:N > of ~140:0 when away from the transiever, and ~160:0 when near. ifconfig > says that media is OFDM/54Mbps. I says that probably the units are > totally arbitrary, or the ndis driver is just being piss-proud [i.e., > exaggerating a little, and his signal is not really that big] ;) ndis is useless in this area. Comparing it's operation to ath is also rarely meaningful as the ndis driver includes certain features that the native driver does not (e.g. s/w tx retry and support for xr mode--useful only when talking to an Atheros AP). > > Now, I didn't do any real performance comparison yet (ath vs ndis), but > I can say this: ath performance seems to me rather disappointing -- the > carrier gets lost from time to time, range is not impressive (or am i > just expecting too much?), there's absolutely no reception without > antenna connected (I believe this isn't right), etc... I've not recently tested the particular chip in the DWL-G520 but in the past it's been ok. If I recall correctly it's used in at least one widely distributed commercial product using freebsd and my driver. What is going on here is unclear and is par for the course--diagnosing wireless problems can be very hard and snapshots of data are rarely meaningful. What you need to do to get a baseline is isolate the stations and run tests at each tx rate and w/ a fixed/known attenuation. You measure throughput and verify the system is doing what is expected (this is called a waterfall test and is usually done with stations wired together in separate rf isolation chambers). Past that you need to test how the system behaves in the face of noise. All of this has been done repeatedly for this stuff and I have confidence in it. There are ways to diagnose what is going on such as locking the transmit rate and running unidirectional blast tests to measure packet error rate. These can identify whether problems are on the sending or receiving side. > > I don't have much time to look into the issue now, but if someone will > suggest how to do some advanced testing (at almost a step-by-step > level), I would do that. See above. Sam From owner-freebsd-hardware@FreeBSD.ORG Sun Jan 14 18:40:24 2007 Return-Path: X-Original-To: freebsd-hardware@freebsd.org Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id CD3AE16A417 for ; Sun, 14 Jan 2007 18:40:24 +0000 (UTC) (envelope-from sam@errno.com) Received: from ebb.errno.com (ebb.errno.com [69.12.149.25]) by mx1.freebsd.org (Postfix) with ESMTP id A475E13C45E for ; Sun, 14 Jan 2007 18:40:24 +0000 (UTC) (envelope-from sam@errno.com) Received: from [10.0.0.199] ([10.0.0.199]) (authenticated bits=0) by ebb.errno.com (8.13.6/8.12.6) with ESMTP id l0EIeOeV025788 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 14 Jan 2007 10:40:24 -0800 (PST) (envelope-from sam@errno.com) Message-ID: <45AA7918.2020603@errno.com> Date: Sun, 14 Jan 2007 10:40:24 -0800 From: Sam Leffler Organization: Errno Consulting User-Agent: Thunderbird 1.5.0.9 (Macintosh/20061207) MIME-Version: 1.0 To: Trigve Siver References: <20070114142837.13776.qmail@web52714.mail.yahoo.com> In-Reply-To: <20070114142837.13776.qmail@web52714.mail.yahoo.com> X-Enigmail-Version: 0.94.1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-hardware@freebsd.org Subject: Re: DWL-G520 low signal, low speed X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Jan 2007 18:40:24 -0000 Trigve Siver wrote: > Hi, > > One more thing I want to add is...that when I was using ath I have had low speed and also had a lot of interupts and I realised that ath was sharing IRQ with USB (IRQ 19 in my case)... so I disabled the USB and throw away ath from kernel and compile it as module (want to take some performance test with ndis and ath)...and after that I have still low signal but media is OFDM/54 Mbps and is stable... to the performance....I think that ndis is somehow a little faster...when dowloading/uploading about 100 kB/s faster...but haven't done some serious testing (don't know how maybe with kismet?) Downstream performance is mostly dependent on performance of the sender. 100 kB/s (kilobits?) is likely not significant which means the radio operation are likely similar. If you really want to compare what's going on collect a packet trace of both drivers and look at the tx rates and other characteristics. The interrupt rate you cited original is too high. I believe your card has on-chip counters for phy errors which means you should get only interrupts for real frames and that's typically max's out at ~4K/sec when running full out in both directions. More typical packet rates are <1K and there are some interrupt mitigiation techniques used to bring the interrupt rate lower than that. BTW top-posting means all context is lost when I reply; it is discouraged. Sam