[MLB-WIRELESS] links

mw at freenet.net.au mw at freenet.net.au
Fri Sep 10 20:54:17 EST 2010


G'day,

Yes, WDS is ok, but WDS nodes retransmit everything they receive - thus bandwidth/2

Correct me if I'm mistaken, but my understanding is that wifi protocol has some limitations on bridging because the client (station) mac address is used in the underlying protocols in such a way that it is not possible for mac addresses of other devices behind the client to appear on the AP network.  The AP side, on the other hand, is transparent - all mac addresses on the AP lan are exposed to all clients.

I suppose it all makes perfect sense in the original context of WiFi: an AP bridge with wireless clients (i.e. clients only, not networks) connected to it. 

WDS is a solution because both AP and client are, essentially AP mode devices.  The trade off is that every AP retransmits everything it receives, so you lose half of the maximum available bandwidth. :-(

Unless nanobridges do some kind of proprietary WDS...?

Anyhow, I'm not talking about strictly point to point bridge, I'm talking about lan to lan bridge.  What 'airOS' calls 'bridge' with AP/station modes works fine for a p2p when there is only one mac address behind each end, so using mikrotik eoip tunnels at each end turns it into a full speed transparent bridge.

Cheers!

Mike.

> -----Original Message-----
> From: Michael Vale [mailto:masked at internode.on.net]
> Sent: Friday, 10 September 2010 8:25 PM
> To: mw at freenet.net.au
> Subject: Re: [MLB-WIRELESS] links
> 
> Ive found the nanobridges to work fine as ptp bridges in wds mode, what are
> you talking about?!
> 
> mw at freenet.net.au wrote:
> 
> >Hi All,
> >
> ><dang> completely forgot about a meeting coming up this week, so I'll be
> >missing out this month.
> >
> >But wanted to announce a few comments that may be of interest to other
> >Geelong members...
> >
> >I replaced a point to point link between KBN and KBQ with a ubiquiti
> >nanobridge M5 pair.  Results are great, but I did discover one small
> >downside of nanobridge systems: they are crap bridges! ;-)
> >
> >Funny about that, youd think that something with 'bridge' in the name
> would
> >be good for that kind of purpose, but it turns out that although it is
> >excellent to connect to routers together, when they are used to bridge two
> >LANs, the results are disasterous.  I suppose their forwarding tables get
> >mixed up and suddenly everything goes to pot.
> >
> >Nonetheless, by connecting them to a mikrotik router at each end then
> using
> >routerOS ethernet-over-ip tunnels, a very effective transparent bridge can
> >be implemented over the very good air performance of the nanobridge
> systems.
> >
> >The results I get over the 7.5 Km link using routerOS Bandwidth test
> between
> >the routers at each end is 84 megabits of udp and around 60 megabits of
> TCP
> >traffic - not bad at all! :-)
> >
> >Having said all that, I also wanted to mention that I set up some scaffold
> >at this end (KBN) and will leave it there for a couple of weekends while I
> >fix up some other jobs I've been meaning to do for ages, including upgrade
> >of the 2.4GHz AP and link to JEE, so those guys who have been wanting to
> try
> >some links into Geelong and to Lara - about now is a good time to be
> >thinking more about that! ;-)
> >
> >Cheers,  Mike.
> >
> >
> >_______________________________________________
> >Melbwireless mailing list
> >Melbwireless at wireless.org.au
> >https://wireless.org.au/mailman/listinfo/melbwireless





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