From owner-freebsd-net@FreeBSD.ORG Sat Feb 20 21:55:47 2010 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF4BF106566B for ; Sat, 20 Feb 2010 21:55:46 +0000 (UTC) (envelope-from rpaulo@gmail.com) Received: from mail-ew0-f211.google.com (mail-ew0-f211.google.com [209.85.219.211]) by mx1.freebsd.org (Postfix) with ESMTP id 7E7CD8FC0C for ; Sat, 20 Feb 2010 21:55:46 +0000 (UTC) Received: by ewy3 with SMTP id 3so1213415ewy.13 for ; Sat, 20 Feb 2010 13:55:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:subject:mime-version :content-type:from:in-reply-to:date:cc:content-transfer-encoding :message-id:references:to:x-mailer; bh=tZUVYmOISkW+fR0RIn18Wq0/JPU548wsXhbJMy/5YNo=; b=dl4jaqb+7jOrABJSVadXp/807B/g9nQohcGzCAksDN+jD9gFQlC+2mh9TWaCgEjwh/ vj2P/RRkc3qh605klpRxaeYbduL1gRcilcn386HC0wwqI2X7S62ubbg62M7EXxZFOC4r CHyhfxsVH4K5JWu6/Z0hv8GxAveJytnlhnSys= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; b=ZxkP4gJ2LHV0ZFmRECuKpbEcueTQmXZW1mIS5ZS7cajcsR6DGdJXjue0RVkg/2lejL lKnu8xA2Ix/JfS1QPrCWkkOCMmR7qfCBeHU1uaJFZ/qo6WVuqusGppuJnZJTVsAkCwQo S0t9Fa2MSexm1pN/rrKGHkd+mlvRir/v53i4g= Received: by 10.213.100.160 with SMTP id y32mr2419971ebn.49.1266702945404; Sat, 20 Feb 2010 13:55:45 -0800 (PST) Received: from ?10.0.10.4? (54.81.54.77.rev.vodafone.pt [77.54.81.54]) by mx.google.com with ESMTPS id 28sm5127548eye.31.2010.02.20.13.55.42 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sat, 20 Feb 2010 13:55:43 -0800 (PST) Sender: Rui Paulo Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset=us-ascii From: Rui Paulo In-Reply-To: <4B80595F.2050406@errno.com> Date: Sat, 20 Feb 2010 21:55:41 +0000 Content-Transfer-Encoding: quoted-printable Message-Id: References: <2d3b7e441002100446k36493e24ldef6d4e335092b7f@mail.gmail.com> <4B73274E.1050902@freebsd.org> <2d3b7e441002101401x2f6f5f28i5ee3b63c18e6b1ed@mail.gmail.com> <4B80595F.2050406@errno.com> To: Sam Leffler X-Mailer: Apple Mail (2.1077) Cc: freebsd-net@freebsd.org, Alexander Egorenkov Subject: Re: net80211 and PPI header X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Feb 2010 21:55:47 -0000 On 20 Feb 2010, at 21:51, Sam Leffler wrote: > Alexander Egorenkov wrote: >>> What exactly do you need? We should be able to extend radiotap. >>>=20 >> 1. Not only one RSSI but for every antenna (also in dBm) >> 2. HT greenfield/HT mixed indicator >> 4. Number of spatial streams (STBC) >> 3. A-MPDU support (MPDU density, A-MPDU reassembly) >> The most important one is A-MPDU support, i think. >> Wireshark supports PPI header and can handle A-MPDUs very nicely. >> That's it for now :-) >=20 > I discussed integrating PPI w/ radiotap back when I did the existing = 11n support but never got anywhere (>3 years ago?). The PPI stuff was = done under contract to Intel and the folks involved never contacted = anyone about doing it within radiotap instead. It looked entirely = possible to leverage the PPI decoder in wireshark to handle AMPDU = reassembly from the radiotap decoder but I never got to it. >=20 > As to the other state Greenfield was nonexistent (and unclear if it'd = make it out of draft status) when I did stuff or I'd have reserved a bit = for it. The # of streams can be implied from the MCS unless I = misunderstand. I do want the per-antenna/chain state (rssi, nf, evm) = but was looking for things to stabilize before adding to radiotap--each = device/driver exports different data and I wanted something that was = enough of a superset to handle the most devices. Adopting PPI data = structures would be reasonable. >=20 > I would prefer to not emit PPI but instead augment radiotap. We've = standardized on radiotap for 802.11 and all the drivers now use it (or = should use it). I'll leave it to others to deal w/ the politics of the = radiotap noobs; the technical details of doing this are straightforward. FWIW, I have very basic support of PPI headers on my 11n branch. -- Rui Paulo