ath(4) and 802.11g speed

[Sam Leffler]

Daniel O'Connor wrote:
> On Thursday 09 March 2006 10:41, JoaoBR wrote:
>>> It looks like "man ath" does not list all media and mediaopt values.
>> sure not because there are lots of different cards out with different
>> mediaopts so you need to read your hw-manual or your card can answer
>> ifconfig -m ath0
> 
> In any case I imagine there is no point forcing it to use 54Mbit - it will 
> negotiate the highest speed it can manage based on signal strength and 
> hardware support (for the AP and the card) automatically.
> 
> I suspect forcing 54Mbit will either not work at all (because the signal isn't 
> strong enough or your hardware doesn't support it), or it will negotiate a 
> speed up to 54Mbit (which would result in no functional change).
> 

Locking the transmit rate (and that's what setting the media does) can 
be useful but rarely when operating in any configuration but a p2p setup 
where the endpoints are fixed.  The algorithm used to select a transmit 
rate for a frame is very important to getting good performance.  John 
Bickett's sample algorithm, typically used with ath, is pretty good but 
could still be improved.

	Sam