Date: Sat, 20 Feb 2010 21:55:41 +0000 From: Rui Paulo <rpaulo@freebsd.org> To: Sam Leffler <sam@errno.com> Cc: freebsd-net@freebsd.org, Alexander Egorenkov <egorenar@googlemail.com> Subject: Re: net80211 and PPI header Message-ID: <C09F205D-14FE-47C2-A415-36624D0605D7@freebsd.org> In-Reply-To: <4B80595F.2050406@errno.com> References: <2d3b7e441002100446k36493e24ldef6d4e335092b7f@mail.gmail.com> <4B73274E.1050902@freebsd.org> <2d3b7e441002101401x2f6f5f28i5ee3b63c18e6b1ed@mail.gmail.com> <4B80595F.2050406@errno.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 20 Feb 2010, at 21:51, Sam Leffler wrote: > Alexander Egorenkov wrote: >>> What exactly do you need? We should be able to extend radiotap. >>>=20 >> 1. Not only one RSSI but for every antenna (also in dBm) >> 2. HT greenfield/HT mixed indicator >> 4. Number of spatial streams (STBC) >> 3. A-MPDU support (MPDU density, A-MPDU reassembly) >> The most important one is A-MPDU support, i think. >> Wireshark supports PPI header and can handle A-MPDUs very nicely. >> That's it for now :-) >=20 > I discussed integrating PPI w/ radiotap back when I did the existing = 11n support but never got anywhere (>3 years ago?). The PPI stuff was = done under contract to Intel and the folks involved never contacted = anyone about doing it within radiotap instead. It looked entirely = possible to leverage the PPI decoder in wireshark to handle AMPDU = reassembly from the radiotap decoder but I never got to it. >=20 > As to the other state Greenfield was nonexistent (and unclear if it'd = make it out of draft status) when I did stuff or I'd have reserved a bit = for it. The # of streams can be implied from the MCS unless I = misunderstand. I do want the per-antenna/chain state (rssi, nf, evm) = but was looking for things to stabilize before adding to radiotap--each = device/driver exports different data and I wanted something that was = enough of a superset to handle the most devices. Adopting PPI data = structures would be reasonable. >=20 > I would prefer to not emit PPI but instead augment radiotap. We've = standardized on radiotap for 802.11 and all the drivers now use it (or = should use it). I'll leave it to others to deal w/ the politics of the = radiotap noobs; the technical details of doing this are straightforward. FWIW, I have very basic support of PPI headers on my 11n branch. -- Rui Paulo
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C09F205D-14FE-47C2-A415-36624D0605D7>