From owner-freebsd-net@FreeBSD.ORG Wed Jan 27 19:14:54 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 792FB106566C for ; Wed, 27 Jan 2010 19:14:54 +0000 (UTC) (envelope-from egorenar@googlemail.com) Received: from mail-ew0-f218.google.com (mail-ew0-f218.google.com [209.85.219.218]) by mx1.freebsd.org (Postfix) with ESMTP id 0BD4C8FC0A for ; Wed, 27 Jan 2010 19:14:53 +0000 (UTC) Received: by ewy10 with SMTP id 10so1614659ewy.3 for ; Wed, 27 Jan 2010 11:14:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=aGk1+Z5hBQt/EvgdymWLUmUqZbczhXvLgMU7R+6tMNk=; b=JmpitbUnFeP46vm5jt6sreFhnSFj/KmlNVi8mtnEEWCB9sWCdbwArKIXN9QVRNxCpb Z2XRjM/mQWguzhUeMG2fXOlD/vFUbfepW1GqR3W8PyCoMNCmeGBPAgRZpJecQqqMQkgy tL+3yY8JCs7w1ydron+hjBENIvu7p9aQYyO6A= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Sl212mmaqsxkaY7WvCg8r5fQ6yWsrpOKO0IV5N72HK7GiPKE0C/Yg84S8Mia6zCthX qRZJE5HY9RGHewyKKuu09rfsu27XYnZhChVH01+Cb2m5KlQgwFdMNJ+fhU4JNRRx7GYP dA+4i5hXmqhuwRKRtRgBitR5iNhwmBkbEphs0= MIME-Version: 1.0 Received: by 10.213.37.147 with SMTP id x19mr361115ebd.58.1264619286033; Wed, 27 Jan 2010 11:08:06 -0800 (PST) In-Reply-To: <2d3b7e441001271104j14836df4j14428d34561dead1@mail.gmail.com> References: <2d3b7e441001271104j14836df4j14428d34561dead1@mail.gmail.com> Date: Wed, 27 Jan 2010 20:08:06 +0100 Message-ID: <2d3b7e441001271108p2a40dbbbwaa6af9679d61ab@mail.gmail.com> From: Alexander Egorenkov To: freebsd-net@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Re: A-MPDU transmission in net80211 on FreeBSD 8 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: Wed, 27 Jan 2010 19:14:54 -0000 Sorry, i posted the wrong comment. Here is the comment which i don't understand: /* * NB: don't assign a sequence # to potential * aggregates; we expect this happens at the * point the frame comes off any aggregation q * as otherwise we may introduce holes in the * BA sequence space and/or make window accouting * more difficult. * * XXX may want to control this with a driver * capability; this may also change when we pull * aggregation up into net80211 */ Thanks. On Wed, Jan 27, 2010 at 8:04 PM, Alexander Egorenkov < egorenar@googlemail.com> wrote: > > Hi, > > i'm implementing a device driver for a 802.11n NIC under FreeBSD 8 > und experimented with A-MPDU transmission. I looked into net80211 code > and there is some code which implements this feature but it worked not very > well for me. > I noticed e.g. that sequence numbers are not assigned to A-MPDU frames > and found this comment in file ieee80211_output.c : > > > /* > * Check if A-MPDU tx aggregation is setup or if we > * should try to enable it. The sta must be associated > * with HT and A-MPDU enabled for use. When the policy > * routine decides we should enable A-MPDU we issue an > * ADDBA request and wait for a reply. The frame being > * encapsulated will go out w/o using A-MPDU, or possibly > * it might be collected by the driver and held/retransmit. > * The default ic_ampdu_enable routine handles staggering > * ADDBA requests in case the receiver NAK's us or we are > * otherwise unable to establish a BA stream. > */ > > Can somebody elaborate this description to me please. > > Thanks. > > ALex. > >