[Mesh] Pittmesh node

[Stuart Gathman]

On 08/15/2017 10:21 PM, Nicholas Carter wrote:
> Niiiice. Still need to get one of these little guys. This is basically
> my dream of a little outdoor mesh node.
Hardware wise, the AP150 is the same as the unit I picked from Gl.inet. 
Their mesh protocol is OLSR <http://olsr.org/> which has a user space
daemon attempting to track the graph of the mesh and dynamically
adjusting the kernel routing table accordingly.   It also only works
with IP4.

So I want to use the BATMAN-ADV protocol, which does not need to track
the mesh graph.  Nodes broadcast a "Hi! My name is ..." packet every so
often, which can take multiple routes to each other node (there is no
attempt to prevent duplication, only loops in the broadcast).  The one
that arrives first determines the "next hop" route for that destination
(as it is the fastest by demonstration).  Subsequent arrivals are
ignored (preventing said loops).  Batman creates a virtual bridge device
- which can bridge many different interfaces - hence allowing
multi-modal communication on the mesh.

For clear IP6 on the mesh itself, the routers can all announce a fixed
fd00/8 prefix - no central coordination required.  If people really want
IP4, we'll have to have a central authority handing out 10.0.0.0/8
subnets to anyone wanting to run a DHCP server.  There are 65536 /24
subnets in 10.0.0.0/8.  Cjdns of course requires no central coordination.

For DNS, we can avoid centralization (at the cost of giving up
guaranteed global consistency) by using ssb-dns.  But so far, getting
people on ssb has been as difficult as getting them to run their own DNS
server.  I don't thing the routers will run scuttlebot - DNS gateways
for ssb-dns will have to be on something a little bigger.  Even an rpi0
should be able to handle it (I'll be testing at some point).

My batman routers also "just work"  (the one that didn't at a recent
meetup had been reprogrammed for an experiment with trying to use
CoxWifi to carry batman packets - nope, the Cox routers block them just
like the library).   OLSR could run if Cox/library allow UDP broadcast. 
There also need to be some standard WAPs for android/windows/apple to
connect via Wifi.  This just occurred to me (yeah, duh!).  I don't need
to reinvent that wheel - the batman routers just need to bridge the LAN
port to the mesh.

Looking at the Pittmesh AP150 - it is a different brand from the GL-inet
ar150, and from the manual configuration insns, it looks like they are
openwrt and you can install batman instead or OLSR.  We should see if
they support better adhoc data rates.


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