WDS links & P2P mode?

Mike Saywell ms at ecs.soton.ac.uk
Thu Mar 27 06:37:59 EST 2003


Well kind of :)

The wds interfaces are actually ethernet type interfaces, so broadcast
based.  Although they are a point to point link between the base stations,
they're not actually a point to point interface - like you get with
a ppp etc.  The reasoning behind this (I suspect) is so that you can
bridge the interfaces (exactly as you have done).  I'm wondering if they
can be truely point-to-point as this simplifies the addressing :)

The problem with bridging is that it sucks for scaling, turns a mesh
into a tree and as you say sucks for mobility.  Consequently we're nor
using bridging at all, each AP has it's own subnet and we route packets

On a separate note we've also developed so quite neat transparent mobile
IP software, this enables you to keep the same IP address no matter
which access point (and therefore subnet) you're connected to.  I won't
go into details here but it's open source and will be source-forged in
the near future :)



On Thu, Mar 27, 2003 at 11:15:50AM -0000, geeojr at krombie.net wrote:
> Maybe I'm off here; but, when you set up wlan0wds# you are setting up a
> point-to-point link between two master mode stations. It's two sided, both
> ends need to be aware of each other - and there's even the options (though
> I've not made it work) for them to 'auto discover' each other.
> Once you have your p2p (wds) links established they are present at each
> stations wlan0wds# interface. What you do with this interface is at your
> discression. Typically (so I assume) most people, myself included, just
> want a bigger coverage pattern for their wireless network and just
> establish the p2p (wds) links and then bridge across it all. As an example,
> I have assign one AP to handle all DHCP for whole net (AP #1). Each AP is
> also connected to a wired network and handles routing/MASQ where
> applicable. The whole wireless network is in the same /24. 
> If you're wanting roam ability; it seems almost essential to stay in the
> same network. The only headache is waiting on each AP in the bridge to
> learn new location. But, this is nothing, in my experience, compared to
> trying to have the host re-aquire a new network address. This usually
> causes more problems.
> Hopefully this might help -- maybe I'm not understanding what it is you're
> hoping to accomplish with the point-to-point
> Jeremy R. Geeo
> ---- Original Message ----
> from: "Mike Saywell" <ms at ecs.soton.ac.uk> 
> to: <hostap at shmoo.com> 
> sent: Mar 27 2003 05:40:43 AM
> subject: WDS links & P2P mode?
> Hi,
> I'm wondering if it would be technically possible to add a pointopoint
> mode for WDS interfaces?  We're using HostAP & WDS to setup a routed
> mesh, but each such link currently requires a /30 network, in addition to
> this I'm trying to make the whole thing zero-conf and assigning addresses
> to these links poses a few extra headaches.
> Each HostAP router already has 1 set IP address, so it would be great
> if we could do "ifconfig wlan0wds0 <local ip> pointopoint <remote ip>".
> I realise that the links may not always represent a point to point
> connection, but when they're between 2 HostAP routers they can.  If it's
> something which would pose major problems implementing then I won't
> bother, but if it's relatively easy I might have a go... just trying to
> get an idea as to whether I'm wasting my time! :)
> Thanks,
> Mike Saywell
> Southampton Open Wireless Network
> http://www.sown.org.uk
> ____________________________________________________________
>   Krombie Networks -- http://www.krombie.net

More information about the HostAP mailing list