From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yx0-f171.google.com (mail-yx0-f171.google.com [209.85.213.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 02C53200411 for ; Sun, 13 Nov 2011 23:44:38 -0800 (PST) Received: by yenl7 with SMTP id l7so883279yen.16 for ; Sun, 13 Nov 2011 23:44:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=EeyKqR7dWvAe9PQFC932zk8xahNwxYJ8WcAGNKchB1M=; b=pfsRsw+k+Vpuq7g4RDMskN0nGbsDnSn9OID4ZeIM0R8XiwM4/m7lcmEvbJr47yyNb9 PExEDWlgpWUZ7ztt8n8t+KXkXAmqkW+C9LPm5MtDgjgmQrrNyfELDT3wnbxG5L5T02WM dvWeA9o6tHiBEtUdc/AIGGPU2S+LjNWYTfUwg= MIME-Version: 1.0 Received: by 10.182.59.49 with SMTP id w17mr4734747obq.37.1321256677615; Sun, 13 Nov 2011 23:44:37 -0800 (PST) Received: by 10.182.15.40 with HTTP; Sun, 13 Nov 2011 23:44:37 -0800 (PST) In-Reply-To: References: <20111114022209.GA5769@brevard.conman.org> Date: Mon, 14 Nov 2011 08:44:37 +0100 Message-ID: Subject: Re: A tiny almost sorta kinda nearly minimal perfect hash for a mac classifier? From: Dave Taht To: Fred Baker Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: bloat-devel@lists.bufferbloat.net X-BeenThere: bloat-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Developers working on AQM, device drivers, and networking stacks" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Nov 2011 07:44:39 -0000 On Mon, Nov 14, 2011 at 3:41 AM, Fred Baker wrote: > > On Nov 14, 2011, at 10:22 AM, Sean Conner wrote: > >> =A0Why not just use the lower N bits as the hash function? > > or > > unsigned macHash (unsigned long long =A0macAddressClone) { > =A0 =A0 return 0xFFF & (macAddressClone ^ (macAddressClone >> 12)); > } > > That allows you to keep different OUIs separated somewhat. I should probably not have used 'arp' as an example, but suggested tcpdump. Multicast and broadcast on 802.11 are 'special'. They are always transmitted at the lowest rate possible (and eat up correspondingly far more airtime), and in the case of power save mode, can be deferred up to 200 ms, to wait for stations to be awake enough to 'hear' them. So anything with the multicast mac bit set should end up dumped in a special queue to manage that better. Virtual interfaces on a given radio twiddle on the local mac bit and then do arbitrary transforms elsewhere on the mac > _______________________________________________ > Bloat-devel mailing list > Bloat-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat-devel > --=20 Dave T=E4ht SKYPE: davetaht US Tel: 1-239-829-5608 FR Tel: 0638645374 http://www.bufferbloat.net