MPP tests

[Giannis Galanis]

On my last week at 1cc, I performed several tests on MeshPortalPoint(MPP)
configurations.

Perhaps it is good for all to have an insight on what is possible, and what
isnt with MPP.
(especially after tomorrows network presentation!)

For those who dont know yet,  an XO  acts as an MPP, when it manages to
share its private internet connectivity to other XOs in the mesh.

The MPPs tested managed to successfully share their connectivity through the
msh0 interface.
Their connectivity was via
1) a GSM/usb modem though a ppp0 interface(thanks to Ankur!!)
2) a simple Wifi AP
3) a School Wifi

The common cases of MPP regarded home scenarios, or "under-the-tree"
scenarios(where at least 1 XO had access to an internet connection)
Specifically in the GSM modem case, probably only one XO will have the
device due to cost.. etc

But, it was rarely discussed whether an MPP can be useful at the school(am i
wrong?)
Probably because Schools were initially configured with Meshes, and the MPP
is probably useless there
(if the MPP, XO, School are indeed in the same mesh, then the XO can reach
the School directly)

However, now that Schools are mostly connected with Access points, MPP can
be useful in School as well!

Other XOs in the neighborhood can join a School Wifi via an MPP,
combining the benefits of the AP in the dense environment, and the Mesh in
the scarce environment

***Michali*, I have a question for u:
In the case that some XOs are many hops away(>5 and <10) from the School,
can an XO at halfway act as an MPP to practically increase the ttl?
I can understand that it would probably work if the MPP had two mshX ifaces
on diff channels(the second to be an active antenna)..
Is this a good way to bridge two mesh clouds?


Results:

1) GSM modem / SimpleWifi

* All XOs (including the MPP) had access to the internet
* The client-XOs showed a DNS server(in resolv.conf) of the msh0 address of
the MPP-XO
* jabber:All XOs(including the MPP) could perfectly collaborate via a jabber
server(any publicly routable jabber should work.. i used
schoolserver.laptop.org)
* salut: I disabled gabble in all XOs with "sugar-control-panel -s jabber
foo"
   a) All XOs(including the MPP) shared *Presence information*.. i.e. New XO
arrivals, new activities, who joins the activity..etc
   b) Only the client-XOs could perform actual collaboration!!
why is this happening? I found it rather strange..
I was under the impression that Presence data were very similar to Activity
sharing data..
*Dafydd*, can you explain this? (or anyone from collabora)

2) School Wifi.. tested with media lab 802.11, which is also connected to
schoolserver.laptop.org

All the above facts were also true here.

What makes this case more special than simple Wifi, is that the client-XOs
would share the benefits of being at the school.
However,
* The client-XOs could *not* Register
* They also could *not* resolve "schoolserver"(it is the simplest way to
tell whether the School "services" are accessible)
(it could ping schoolserver.laptop.org, but this is publicly routable
anyway)
* They could ping 172.18.0.1

Basically, they could reach the school server machine, but didnt treat it as
a school!

*Wad*, can you explain this behavior?



yanni



<http://schoolserver.laptop.org/>
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