From owner-freebsd-net@FreeBSD.ORG Sun Jan 31 07:34:49 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 D99A91065670 for ; Sun, 31 Jan 2010 07:34:49 +0000 (UTC) (envelope-from egorenar@googlemail.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 64FE98FC1B for ; Sun, 31 Jan 2010 07:34:48 +0000 (UTC) Received: by ewy3 with SMTP id 3so253104ewy.13 for ; Sat, 30 Jan 2010 23:34:48 -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:cc:content-type; bh=/wORyAgtMkB4ffMuMs/W2Obko3cQpV6GT3M360Wed40=; b=qxR3H8Ji4MFJdo+tTuNrGBkqAC+Qkafq789UocmFgpFtZqq4KTHrLHFIJFlM3fRDih WNazg6lMkW8P7dFdDZm7J1RLbLzrgt9Qe2SdKrrLeqk+tNp+j/owc+8R6MA0KA/j4tTp nBRnWNyEF7NZi5gZ7f29Vd1978oakGFAUi3SM= 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 :cc:content-type; b=u4I4dhcxRAq7So7gFloVBYPJ8TRBU1FZeiZdIeupGGXkvhtG4kqY3P50sl788FxMoC IY+Ja8SY3SO0oiCkzzBAzLsLSgeTB6a3fsI4hQ7Z3RXF+7YdeXYCMMlemiqtK/9L9Xr6 ThSIFpLshWbTp5UnuztQrohKS7NkfKdoSSss4= MIME-Version: 1.0 Received: by 10.213.109.70 with SMTP id i6mr2840449ebp.16.1264923288196; Sat, 30 Jan 2010 23:34:48 -0800 (PST) In-Reply-To: <4B64FC76.5060506@errno.com> References: <2d3b7e441001271104j14836df4j14428d34561dead1@mail.gmail.com> <2d3b7e441001271108p2a40dbbbwaa6af9679d61ab@mail.gmail.com> <4B64FC76.5060506@errno.com> Date: Sun, 31 Jan 2010 08:34:48 +0100 Message-ID: <2d3b7e441001302334t5baa1102pdd1ee0309d32c2fd@mail.gmail.com> From: Alexander Egorenkov To: Sam Leffler Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-net@freebsd.org 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: Sun, 31 Jan 2010 07:34:49 -0000 Why doesn't 802.11 stack assign sequence numbers to A-MPDU frames ? When sequence numbers are not assigned to A-MPDU frames, then BA doesn't work with my AP. I tried to assign sequence numbers to A-MPDU frames in my device driver and then BAs worked with my AP. And what is meant by aggregation queue ? Where is that queue anf how do i use it ? Thanks. On Sun, Jan 31, 2010 at 4:43 AM, Sam Leffler wrote: > Alexander Egorenkov wrote: > >> 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. >> > > What is unclear? > > Sam > > >> >> 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. >>> >>> >>> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >> >> >> >