From owner-freebsd-net@FreeBSD.ORG Sun Jan 31 03:43:51 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 D68401065676 for ; Sun, 31 Jan 2010 03:43:51 +0000 (UTC) (envelope-from sam@errno.com) Received: from ebb.errno.com (ebb.errno.com [69.12.149.25]) by mx1.freebsd.org (Postfix) with ESMTP id 8D09E8FC13 for ; Sun, 31 Jan 2010 03:43:51 +0000 (UTC) Received: from ice.local ([10.0.0.115]) (authenticated bits=0) by ebb.errno.com (8.13.6/8.12.6) with ESMTP id o0V3ho0M076537 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 30 Jan 2010 19:43:50 -0800 (PST) (envelope-from sam@errno.com) Message-ID: <4B64FC76.5060506@errno.com> Date: Sat, 30 Jan 2010 19:43:50 -0800 From: Sam Leffler User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) MIME-Version: 1.0 To: Alexander Egorenkov References: <2d3b7e441001271104j14836df4j14428d34561dead1@mail.gmail.com> <2d3b7e441001271108p2a40dbbbwaa6af9679d61ab@mail.gmail.com> In-Reply-To: <2d3b7e441001271108p2a40dbbbwaa6af9679d61ab@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-DCC-x.dcc-servers-Metrics: ebb.errno.com; whitelist 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 03:43:51 -0000 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" > >