Skip site navigation (1)Skip section navigation (2)
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>

next in thread | previous in thread | raw e-mail | index | archive | help
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"
> 
> 




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4B64FC76.5060506>