From owner-freebsd-stable@FreeBSD.ORG Thu Mar 9 07:46:55 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2CFE716A420 for ; Thu, 9 Mar 2006 07:46:55 +0000 (GMT) (envelope-from joao@matik.com.br) Received: from msrv.matik.com.br (msrv.matik.com.br [200.152.83.14]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7CB5343D4C for ; Thu, 9 Mar 2006 07:46:54 +0000 (GMT) (envelope-from joao@matik.com.br) Received: from anb (anb.matik.com.br [200.152.83.34]) by msrv.matik.com.br (8.13.4/8.13.1) with ESMTP id k297kpvQ029076 for ; Thu, 9 Mar 2006 04:46:51 -0300 (BRT) (envelope-from joao@matik.com.br) From: JoaoBR To: freebsd-stable@freebsd.org Date: Thu, 9 Mar 2006 04:46:40 -0300 User-Agent: KMail/1.9.1 References: <20060308231529.GA2049@afflictions.org> <200603091105.38164.doconnor@gsoft.com.au> <440FAA67.7020708@errno.com> In-Reply-To: <440FAA67.7020708@errno.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200603090446.40787.joao@matik.com.br> X-Filter-Version: 1.11a (msrv.matik.com.br) X-Virus-Scanned: ClamAV version 0.88, clamav-milter version 0.87 on msrv.matik.com.br X-Virus-Status: Clean Subject: Re: ath(4) and 802.11g speed X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Mar 2006 07:46:55 -0000 On Thursday 09 March 2006 01:09, Sam Leffler wrote: > Daniel O'Connor wrote: > > In any case I imagine there is no point forcing it to use 54Mbit - it > > will negotiate the highest speed it can manage based on signal strength > > and hardware support (for the AP and the card) automatically. > > > > I suspect forcing 54Mbit will either not work at all (because the signal > > isn't strong enough or your hardware doesn't support it), or it will > > negotiate a speed up to 54Mbit (which would result in no functional > > change). > > Locking the transmit rate (and that's what setting the media does) can > be useful but rarely when operating in any configuration but a p2p setup > where the endpoints are fixed. The algorithm used to select a transmit > rate for a frame is very important to getting good performance. John > Bickett's sample algorithm, typically used with ath, is pretty good but > could still be improved. > I am not so sure that the speed is locked when setting to standard speed wh= at=20 is 54 for 11a/g and 11Mbps for 11b the card then chose the the best speed it can negociate with the AP and eve= n=20 if connected in 54 or 11Mbps it chose the next lower speed when packages ar= e=20 lost but goes up soon the conditions are better again. but when you set the card to a lower speed as 2 or 5.5 you force it to stay= at=20 this speed which may be usefull in noisy environments or longer distances=20 especially adhoc connections.=20 Jo=E3o A mensagem foi scaneada pelo sistema de e-mail e pode ser considerada segura. Service fornecido pelo Datacenter Matik https://datacenter.matik.com.br