[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Direction of wireless networking in Fedora ( was RE: Wireless update to ifup and network-functions )



On Thu, 2004-09-16 at 02:33 +0100, Jonathan Andrews wrote:
> Wireless discovery in general isn't going to be easy across
> distributions because for reasons purely political (as far as I can
> tell???) the promisc mode was left on the cutting room floor !!! WHY
> !!!!
> 
> I would have thought that tune, and listen would be the first two things
> any wireless driver would be able to do.

Having looked a _lot_ at kernel wireless drivers in the past 2 months
while developing NetworkManager, I'm not quite sure what the problem
here is...

Major wireless cards and drivers:
Orinoco (Intersil, Wavelan, Airport, etc)
Cisco Aironet
Atmel
Prism54
Intel 2100/2200

Almost all wireless drivers (with the notable exception of the Orinoco
drivers, but that's upstream and currently filtering down in the kernel
drivers) support wireless scanning (ie, returning a list of access
points the card can see) to some degree in the latest kernels, from
2.6.6 and up.  That's really what you need for good wireless support of
the "it just works" type.

What _isn't_ good is the inconsistency of the drivers in supporting the
same types of options.  For example:

(1) signal strength/noise is not normalized between drivers, and the
Atmel driver doesn't support signal strength data of scanned access
points.  Cisco drivers report totally different strength metrics for
scanned access points and for the current access point too.

(2) WEP/Authentication: Cisco drivers, for example, require a WEP key to
be used when using Open System Authentication, which is just plain
wrong.  You don't need to use encryption when using Open auth.

(3) Link detection.  Only a few drivers (Orinoco, Intel) use the
netif_carrier_on/off kernel interfaces for link detection.  However,
they use them mostly _wrong_.  The general idea of a link-on status
should be when the card has authenticated with the base station and
traffic can flow (whether or not you're using the correct WEP key
doesn't seem to be detectable with Open System Authentication, so that's
another problem).

What needs to be done?  Normalize signal strength, and start using the
correct idea of carrier on/off, fix freezes (Cisco drivers seem unstable
on more recent kernels), and get Orinoco cards to support scanning
(being worked on, albeit not fast).

Dan



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]