Date: Sat, 30 Jan 2010 19:43:50 -0800 From: Sam Leffler <sam@errno.com> To: Alexander Egorenkov <egorenar@googlemail.com> Cc: freebsd-net@freebsd.org Subject: Re: A-MPDU transmission in net80211 on FreeBSD 8 Message-ID: <4B64FC76.5060506@errno.com> In-Reply-To: <2d3b7e441001271108p2a40dbbbwaa6af9679d61ab@mail.gmail.com> References: <2d3b7e441001271104j14836df4j14428d34561dead1@mail.gmail.com> <2d3b7e441001271108p2a40dbbbwaa6af9679d61ab@mail.gmail.com>
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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" > >
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