Wireless NIC recommendation

[Kevin Downey]

On 1/15/07, Sam Leffler <sam at errno.com> wrote:
> John Nielsen wrote:
> > On Monday 15 January 2007 15:54, Lars Stokholm wrote:
> >> John Nielsen wrote:
> >>> On Monday 15 January 2007 12:54, Lars Stokholm wrote:
> >>>> Hi, I hope someone can help me with this, before I go mad (no pun
> >>>> intended.) :)
> >>>>
> >>>> I was initially looking for a relatively cheap 54Mbps, 802.11g- and
> >>>> WPA-capable network card, based on an Atheros chipset, but after
> >>>> spending the whole of last night looking for one - to no avail - I gave
> >>>> up.
> >>>>
> >>>> I'm almost about to conclude that Atheros is not the way to go. So now I
> >>>> want to know, if anyone can recommend ANY card, being cheap and
> >>>> supporting the features mentioned above. I don't mind using NDIS, as
> >>>> long as it works flawlessly. Also it would be good, if the card was a
> >>>> popular one, so community support is more available.
> >>> For driver support in FreeBSD, Atheros is definitely the way to go. Have
> >>> you looked through the listings here?
> >>>
> >>> http://customerproducts.atheros.com/customerproducts/default.asp
> >> Wow, I actually think I found a card there, that is guaranteed to work.
> >> Is this really the end of all my struggles? :) For only 50 USD. There
> >> seem to be only one version of the card.
> >>
> >> http://www.dlink.com/products/?pid=12
> >> http://edbpriser.dk/Products/Listprices.asp?ID=38373 (in Danish)
> >>
> >> The two cards /are/ the same, right?
> >
> > This is actually the card I have and use in my FreeBSD box as an access point
> > (I didn't know it was still available or I would have said so sooner.) Yes,
> > they should be the same.
> >
> > There is an early revision ("A1") card of the same name that actually used a
> > non-Atheros chip, but anything you buy today should be "B" or "C" and work
> > fine. I have the "B" revision.
> >
> > Check out the D-Link website (pretend like you're looking for a Windows
> > driver) for slightly more information on the different revisions and how to
> > identify them.
> >
> >> Also, it says 108Mps? Does it matter that my AP is only 54Mbps?
> >
> > Shouldn't matter at all. 108Mbps is often advertised and rarely
> > used/practical. The idea is to use two 54Mbps streams at once. You need to
> > have a card (and driver) that suport it ("Super-G" or "Extreme-G"), an AP
> > that supports it and that acknowledges that your card supports it, and little
> > to no other traffic or interference, since most AP's will automatically fall
> > back to 54Mbps at the drop of a hat. I'm not sure if ath(4) supports it or
> > not, but I've never really cared too much.
>
> Thanks, your description is good.  Let me try to elaborate.  108Mb/s is
> the marketing speak for cards that are capable of Turbo mode.  Turbo
> mode is a chip feature whereby a 2x wide channel is used to get
> effectively 2x the bandwidth.  Radios capable of doing turbo mode can do
> this in either 2.4G or 5G.  When configured to use turbo mode only it's
> said you are operating in "static turbo mode".  When the driver switches
> the radio between turbo and non-turbo operation on the same frequency
> then it is said you are using "dynamic turbo mode".  You are not
> supposed to use static turbo in 2.4G, only dynamic turbo.  In 11a you
> can use either.
>
> The freebsd driver only supports static turbo mode.  It's done so since
> the first commit.  The current linux driver supports both static and
> dynamic turbo modes.  I have support in p4 for dynamic turbo but to be
> honest it's not really useful and you cannot use it when operating as an
> ap unless you also do radar detection so you can drop out of turbo mode
> when you hear non-turbo stations operating on the channel.
>
> In testing I routinely see 40+ Mb/s using static turbo mode with tcp
> netperf; probably more (been a while).  If you add in some other stuff
> that is part of the Atheros SuperG protocol (vendor-specific extensions
> to 802.11) then you can get 60+ Mb/s.  Under certain circumstances you
> can hit 90+Mb/s.  The code in p4 supports most of the important bits to
> get 60+ with turbo mode under good conditions.
>
> Finally, understand also that 11n is coming along very soon and will
> have interoperability and higher throughput than SuperG.
>
>         Sam
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Any hints on what the 11n landscape will look like for freebsd?
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