From owner-freebsd-stable@FreeBSD.ORG Thu Sep 28 15:08:31 2006 Return-Path: X-Original-To: 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 6EEC316A47B for ; Thu, 28 Sep 2006 15:08:31 +0000 (UTC) (envelope-from dudu.meyer@gmail.com) Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.171]) by mx1.FreeBSD.org (Postfix) with ESMTP id D574743D7D for ; Thu, 28 Sep 2006 15:08:22 +0000 (GMT) (envelope-from dudu.meyer@gmail.com) Received: by ug-out-1314.google.com with SMTP id m2so163881uge for ; Thu, 28 Sep 2006 08:08:22 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=i7Yejx8iHpG/6GzZSPIpxah/2eizKsRJV6UFTuuWLlYzW2qQQzmdzGyljY9wulJrVqGG9yRdvbln2P6m/R7xatrssTVWy7H8TeASnLyIYwx2e0a5SW+CuZXYLRb8AlDh++Dg65osCd33HxoXNWbUQp6mycyZBSIXvrD+Eqh6vB0= Received: by 10.67.21.11 with SMTP id y11mr1320174ugi; Thu, 28 Sep 2006 08:08:22 -0700 (PDT) Received: by 10.66.248.4 with HTTP; Thu, 28 Sep 2006 08:08:21 -0700 (PDT) Message-ID: Date: Thu, 28 Sep 2006 12:08:21 -0300 From: "Eduardo Meyer" To: "Sam Leffler" , stable@freebsd.org In-Reply-To: <451AECA0.7000103@errno.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <451AECA0.7000103@errno.com> Cc: Subject: Re: 802.11 RSSI value displayed from ifconfig(8) 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, 28 Sep 2006 15:08:31 -0000 Thank you Mr Leffler for this explanation. Honestly I did not know about those tools. Very interesting, useful and some curious (say, number of associations denied by wlan acl) information, which I believe I will be able to produce some logs of it with audit support. But I did not find any "signal" information nor any value which looks like dBm # athstats -i ath0 4 watchdog timeouts 549821 tx management frames 7 tx frames discarded prior to association 1744404 tx stopped 'cuz no xmit buffer 15 tx linearized to cluster 97625 tx failed 'cuz too many retries 9069518 long on-chip tx retries 422577 tx frames with no ack marked 62850632 tx frames with short preamble 1700110 tx frames with an alternate rate 24280171 rx failed 'cuz of bad CRC 1 rx failed 'cuz frame too large 62560031 rx failed 'cuz of PHY err 4211566 OFDM timing 101667 OFDM restart 58199442 CCK timing 47356 CCK restart 31931664 beacons transmitted 109058 periodic calibrations rssi of last ack: 24 417831 switched default/rx antenna Antenna profile: [1] tx 31753038 rx 33886147 [2] tx 31594701 rx 33711543 # wlanstats -i ath0 1509703 rx discard 'cuz dup 335650 rx frame ssid mismatch 2314 rx deauthentication 377 rx disassociation 4959 rx discard 'cuz acl policy 1068 tx failed for no node 3 active scans started 142 nodes timed out inactivity Note that I am acting in hostap mode. On 9/27/06, Sam Leffler wrote: > Eduardo Meyer wrote: > > Hello, I would like to convert RSSI to dBm (in fact I would love if > > ifconfig cound display SNR in dBM), so I would like to know if this > > formula is any right: > > > > /* Calculate the RSSI Value */ > > V_RSSI = 3.0 * (RSSI_VAL/1024); > > RSSI_dBM = (int8_t) ((-50.0 * V_RSSI) - 45.5); > > > > And if there are any other tools which can help me finding out signal > > stenght, when I am acting as an access point. > > ifconfig reports rssi as whatever the driver provided. The intent is > that it be a signed value relative to the current noise floor (both in > dBm). If you look at the output of wlanstats > (tools/tools/net80211/wlanstats) or, for ath devices, athstats > (tools/tools/ath/athstats) you will see the default displays show > "signal" which is rssi+noise-floor in dBm. The main issue(s) right now > are that the net80211-driver api does not pass noise floor up so it can > be reported to user apps and drivers reports rssi+nf in varying units. > athstats doesn't have that issue since it queries the driver directly > (hence it's display has a reasonable noise floor). > > It's on my todo list to push signal-related data up properly and fix > ifconfig so it displays a proper signal strength in the normal status > display. The issue of units is more difficult as converting data for > some devices to dBm can be tricky. > > Sam > -- =========== Eduardo Meyer pessoal: dudu.meyer@gmail.com profissional: ddm.farmaciap@saude.gov.br