From owner-freebsd-net@FreeBSD.ORG Wed Jan 27 19:31:46 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 13CEB1065693 for ; Wed, 27 Jan 2010 19:31:46 +0000 (UTC) (envelope-from egorenar@googlemail.com) Received: from ey-out-2122.google.com (ey-out-2122.google.com [74.125.78.27]) by mx1.freebsd.org (Postfix) with ESMTP id A19708FC16 for ; Wed, 27 Jan 2010 19:31:45 +0000 (UTC) Received: by ey-out-2122.google.com with SMTP id 9so1533554eyd.9 for ; Wed, 27 Jan 2010 11:31:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:date:message-id:subject :from:to:content-type; bh=GrpyYnE/solfA8eHNkOPzuxMQk07PCfE5Aqd66gOQL8=; b=oj0wTnN9oOBPM0JtWJExUVH902rryVUngtVXur+Md0IWbuWdeyTh1XfX1kAqjSm2n/ jjDejLxM5v9BtmMsKxO0Wc3Mq4b0EN4KsOcaJ8aMp0Bou7V9z0JMsQlrptWAko9y28+7 Baswcr3dmfxS4jtloGLTOwLoQy3Rm2SGoGLoY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=ptcO8q3IVxMivnmRDat2NL5zA0xJeIW8JJ865sjF9Ab/6PxFMjsHBU5QsF/eamIlU8 GlQshsbEfdeC8YxXQZ+ntZYOpT5Fuyilti0LwDG3U461NttLuMETDQVh2BU+jOmQdAh6 4PdXxw1C+S1yXBYPkAerYZqJzkDjjrjLIhHnw= MIME-Version: 1.0 Received: by 10.213.0.148 with SMTP id 20mr1493410ebb.51.1264619049354; Wed, 27 Jan 2010 11:04:09 -0800 (PST) Date: Wed, 27 Jan 2010 20:04:09 +0100 Message-ID: <2d3b7e441001271104j14836df4j14428d34561dead1@mail.gmail.com> From: Alexander Egorenkov To: freebsd-net@freebsd.org X-Mailman-Approved-At: Wed, 27 Jan 2010 19:47:09 +0000 Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: 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 19:31:46 -0000 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.