[OLPC Networking] Re: [olpc-software] "Mesh" Software

[Jim Gettys]

On Tue, 2006-04-18 at 20:48 +0200, Fabian Deutsch wrote:

> 
> Because experimantation can get difficult, if you don't have 100+
> laptops, you might use some simulator to see some protocols in
> action ...
> There is ns-2 (http://www.isi.edu/nsnam/ns/), which supports simulation
> of olsr, aodv and .. isis (similar to ospf) ... and gtnets
> (http://www.ece.gatech.edu/research/labs/MANIACS/GTNetS/) for (ospf,
> ospf-mdr)
> 

No, network simulation won't do what we need.

And we will have of order 100 machines to do experiments with this
summer.  I don't remember the exact numbers in the spreadsheets at the
moment; it is at least 50 boards set aside for this sort of network
experimentation (we are building 500 developer boards, we expect maybe
400 will be functional).

> > 
> > The Marvell wireless chip selected has enough smarts that such behavior
> > could (if one is careful about space use), be done without the main
> > CPU's intervention, by having the processor in the Marvell chip turn on
> > the radio periodically and see if it should participate.
> > 
> 
> I'm really looking forward to the first software for this, I can't
> really imagine how this is going to work and how this will work with
> some kind of routing .. 'cause this is more than just forwarding ...
> init?

Routing will have to be computed by the main CPU; there isn't enough
memory in the Marvell chip; but once tables are computed, it has enough
smarts to be able to forward packets appropriately, and it can also wake
the main CPU when it needs help (or someone needs to wake the main CPU).
                                 - Jim Gettys

-- 
Jim Gettys
One Laptop Per Child