Re: [RFA] HT extensions

[Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>]

On Tue, 2010-10-05 at 13:42 -0500, David Young wrote:
> On Tue, Oct 05, 2010 at 08:27:43PM +0200, Johannes Berg wrote:
> > On Tue, 2010-10-05 at 13:21 -0500, David Young wrote:
> > > How can an application use the first/last-frame information?
> > 
> > Well, right now my wireshark patch is simply displaying it, but it could
> > also link up frames of an a-MPDU so you can jump between them, and with
> > this it can know what the framing was. If you just know a frame was part
> > of an aMPDU you won't know which one, this should help.
> 
> I have my doubts about that.  How do you distinguish the case where the
> NIC gives you the first MPDU of A-MPDU 1 and the last MPDU of A-MPDU 2
> from the case where the NIC gives you the first and last MPDU of the
> same A-MPDU?

You mean with imperfect capturing? Otherwise you should've seen the last
of A-MPDU 1 inbetween that, I'd think. But you're right, doing this
perfectly is quite hard, and I don't really have a good use case in mind
either. I'm happy to leave it off, at least for now, until somebody can
demonstrate a working way to convey this information.

johannes