open 80211s on XO 1.5

Ed McNierney ed at laptop.org
Fri Oct 30 16:23:46 EDT 2009


I can't quite understand the desire for "definitive info" combined  
with your disappointment that you don't have 1.5 "rumors".  I don't  
think we need rumors, and I and many other folks have been providing  
"definitive info" about 1.5 for some time.  And about the mesh, etc.   
You don't say what topic it is on which you want the record set  
straight - if you need info, just ask.

http://wiki.laptop.org/go/XO-1.5
http://wiki.laptop.org/go/Mesh_Network_Details

	- Ed

P.S. The 802.11s draft standard has certainly been implemented on  
other devices; no one suggests it is unique to the XO-1.  What is  
"special" about the XO-1, AFAIK, is its ability to continue to operate  
as a mesh node (or MPP, mesh portal point) and forward packets while  
the laptop is otherwise shut down.  The fundamental limitations on the  
utility of 802.11s in typical XO-1 scenarios, however, limit the value  
of this unique (I think) laptop feature.

On Oct 30, 2009, at 4:12 PM, DancesWithCars wrote:

> I'd said to lots of people that the XO
> uses 802.11s mesh networking
> and eventually ran into someone rather
> geekie and otherwise impressively knowledgeable
> who corrected me that they didn't implement the
> whole standard (and people here say draft).
>
> The Marvel driver is said to be closed source,
> and RMS didn't like that, all of course
> rumor, and another rumor that the
> driver was open sourced.
>
> No rumors on the XO-1.5 yet, which
> is a shame.  Even as hype and pre-release
> getting a buzz going would be nice.
> I don't have one, so can't test it to
> find out. Computer are supposed
> to be a Science, or so Knuth
> is credited by the ACM for
> helping to make that happen,
> documenting the fundamental
> algorithms and all...
>
>
> There are other mesh networking
> and someone once said to me that
> the 802.11s isn't that special
> that mesh OLR or somesuch
> protocols have been around for
> some time, but I'm guessing
> the XO is one of the bigger
> (~1 million XOs out there somewhere)
> publicly known implementations
> in that arena.
>
> So if someone / laptop.org
> wants to set the record straight
> and give definitive info, that would be
> great...
>
> On Fri, Oct 30, 2009 at 3:50 PM, Ed McNierney <ed at laptop.org> wrote:
>> On Oct 30, 2009, at 3:32 PM, Sameer Verma wrote:
>>
>>>  scenarios of a handful of XOs in the under-a-tree model
>>
>> Sameer -
>>
>> Under a tree, using mesh networking is pointless (unless, I suppose,
>> it is an extraordinarily large tree).  Mesh networking allows packet
>> forwarding from node A to node B, where such nodes cannot normally
>> communicate with one another directly.  Packets are forwarded through
>> node C, visible to both A and B, or through multiple such  
>> intermediate
>> nodes.  If A can communicate with B, mesh is neither helpful nor
>> advisable.  It just confuses things, which is the problem we see with
>> large numbers of children in a classroom.  The mesh efforts to keep
>> track of how to get from A to B can quickly saturate the RF spectrum
>> with a lot of unhelpful traffic.
>>
>> I can't tell what it is you're doing at your meetings when your users
>> "all use mesh".  At a typical in-person meeting, you have a number of
>> people using XOs all in the same room.  Any XO in the room can
>> communicate over WiFi directly with every other machine in the room
>> (except in extremely unusual circumstances, or too many attendees
>> wearing their tinfoil hats).  There's no need for or value to mesh
>> network - A doesn't need C to forward packets to B because A can  
>> see B
>> directly as another ad hoc node.
>>
>> If there's an AP providing routing to the Internet or other external
>> networks, there's no mesh required there, either, presuming that each
>> XO can communicate with the AP directly.
>>
>> I can't answer your question about whether those scenarios use ad hoc
>> networking because I don't quite see what it is the users are doing  
>> in
>> those scenarios.  What (lowercase) activity are users engaged in when
>> you say they "all use mesh"?  What do you think they would be unable
>> to do if they all stopped using mesh?  Thanks for the info.
>>
>>        - Ed
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>
>
>
> -- 
> DancesWithCars
> leave the wolves behind ;-)




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