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Date:      Sun, 18 Aug 2002 02:41:29 +0300 (WET)
From:      Evren Yurtesen <eyurtese@turkuamk.fi>
To:        richard childers <fscked@pacbell.net>
Cc:        mobile@freebsd.org
Subject:   Re: IBSS and BSS with multiple FreeBSD Wireless Gateways
Message-ID:  <Pine.A41.4.10.10208180226150.88330-100000@bessel.tekniikka.turkuamk.fi>
In-Reply-To: <3D5E98FF.82CD061E@pacbell.net>

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Yes but thats not what I ment. I want to use only 1 card and antenna for
both bridging/repeating and gateway. I need functionality like in 
some www.speedlan.com products.

I believe this is only possible in hostap mode with prism 2/2.5 cards. I
just wonder in a fully meshed network how can the cards now where to
forward the packets. If the system would look like this for example


            Internet
                |
               hostap1
                /\
               /  \
              /    \
        hostap2-----hostap3
            /      / \
           /   ___/   \ 
          /   /        \
         /   /          \
        hostap4--------client2
          /
         /
      client1


so how can the client2 go through the hostap3 to hostap1 then to internet?
how does hostap3 knows that it shouldnt forward the packet to hostap4 ?

I am kind of confused about this.

I thought if I could give an IP address to each wireless ap and make ip
routing in between then this would work but then roaming wouldnt work and
in the places where the cells are intersecting I would have trouble since
there would be 2 different gateways in the same area.

Isnt it so? Is this impossible to accomplish?

Evren

On Sat, 17 Aug 2002, richard childers wrote:

> I've wondered about this as well.
> 
> Imagine the following simple scenario.
> 
> You are WiFi- and FreeBSD-enabled; so is your friend. For the sake of
> simplicity let's assume that you are directly across from one another in two
> dormitories at approximately the same height.
> 
> You both eliminate signal strength and signal security issues with
> line-of-sight antenna pointed directly into one another's cone of
> transmission.
> 
> At this point you are not unlike two routers with a cable between them, and
> it is only a matter of picking an appropriate class 'C' subnet (IE,
> 192.something), assigning it an appropriately long mask (IE, one preserving
> only two bits of the address for actual networking), bringing the interfaces
> up and adding routing entries on each end.
> 
> Note that your network is still hypothetically subject to eavesdropping and
> jamming from parties in either antenna's line of sight.
> 
> A slightly more complicated scenario emerges when you attempt to add a third
> node; at this point one of the nodes needs to have two cards, with two
> addresses and two antennas and two routing entries.
> 
> I imagine there are some issues with crosstalk between the antennas that
> would need to be addressed with physical separation and maybe some
> appropriate shielding; tin foil works, I expect.
> 
> 
> -- richard
> 
> 
> 
> Evren Yurtesen wrote:
> 
> > Is it possible to use FreeBSD with IBSS or BSS mode as a bridge to
> > overcome line of sight issues? and provide roaming for mobile users?
> >
> > What is the biggest problem if we are using IBSS mode?
> >
> > Another question is if we are using IBSS mode and 2 clients are close
> > to each other but the gateway is little bit more far away. Does it cause
> > the clients to choose each other instead of the gateway because they
> > have stronger signal? If this happens, wouldnt this cause the link to
> > the gateway be broken?
> >
> > Evren
> >
> > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > with "unsubscribe freebsd-mobile" in the body of the message
> 
> --
> 
> Richard A Childers/KG6HAC -- Senor UNIX System & Network Administrator
> "Dont forget nothing." Maj Rogers, standing orders, 1st Ranger Bn, 1759
> 
> 
> 



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