Mesh Quest

[Javier Cardona]

Brian,

On Thu, Feb 12, 2009 at 8:31 PM, Brian DeLacey <bdelacey at gmail.com> wrote:
> Quick follow-up: I upgraded Ubuntu Jaunty (a few  prior builds since Jaunty
> Alpha 4 came out had bugs that prevented my using them.) Today's updates
> seems to have been pretty clean, and I can now mesh machines.
>
> I started with a pair of desktops, both have D-Link cards (one PCI, one a
> PCMCIA card in a PCI adapter.)
>
> I was able to ping these machines successfully bug ONLY AFTER several tasks
> not specified in the HowTo guide:
>
> a) Upgrade to latest Ubuntu Jaunty 2/11/09 updates;
> b) Disconnected physical ethernet connection (in addition to killall on
> NetworkManager);
> c) Shut down the WLAN down (ifconfig wlan0 down);
> d) Set the mode on both MESH interfaces to ad-hoc;
> e) set the mesh interface channel to 5
> f) assign both to the same ESSID (they did boot with the same CELL, which
> isn't true for other WiFi cards / systems);
>
> After I got these two machines meshed together, I configured a third
> machine. This third machine is a netbook - an Acer Aspire One running
> Ubuntu. That was able to connect to the mesh and ping the others. Hooray!
> it's really cool :)
>
> I'm not certain which of these steps are absolutely essential, or what order
> / sequence dependencies might exist. But I'll keep working with this. I'm
> hoping I can reliably reboot the mesh in future startups. Any guidance
> appreciated!

My suspicion is that you are running both cards in plain ad-hoc mode.
You don't need to assign ESSIDs.  Only the mesh_id that you assign
when you bring up the mesh interface
need to match.

Cheers,

Javier

> On Thu, Feb 12, 2009 at 6:48 PM, Brian DeLacey <bdelacey at gmail.com> wrote:
>>
>> I'm excited by the prospects by the mesh code you've developed.
>>
>> I have a handful of machines with wireless cards that look like they
>> should work, since I see "mesh point" interface with lspci. However, I've
>> only had very limited success after many hours of meshing around!
>>
>> I don't have a good overall picture of how this is supposed to work. For
>> instance, if I develop an application (web server, groupware app,
>> interactive game) should I be accessing the mesh via the IP address assigned
>> to the mesh interface, or the IP address associated with the WiFi (wlan0)?
>>
>> I've spent many hours varying configurations and experimenting with
>> settings. Any success is largely unreproducible. For example, I have been
>> able to run "iw dev mesh station dump " and "arp" but I've never been able
>> to get much working with paths: e.g. "iw dev mesh mpath dump" does nothing.
>> Normally, as was the case all day today, I just hit deadends with
>> "Destination Host Unreachable.
>>
>> I'm using Alpha 4 of Jaunty and the latest compat-wireless-2009-02-11 that
>> I compiled/installed today. I've attempted to read through the C-code - it
>> sure looks nice, but I'm just not good enough at C to cover much ground with
>> that approach. I'd gladly switch configs / versions of Ubuntu to make it
>> work.
>>
>> I've followed the HowTo (here) and the excellent blog post (here), but I
>> must be doing something wrong or have some incompatible settings? How should
>> I start to try and debug my config problems?
>>
>> When I try to ping other machines on the network I get "Destination Host
>> Unreachable." I've changed modes to Ad-hoc, renamed ESSIDs, and switched
>> channels around hoping to find the right combination. I've had some success,
>> but nothing is reproducible. (I can ping other machines in simple Ad-hoc
>> mode when setup like this.)
>>
>> I've started my own "Mesh FAQ" at http://meshage.com/MeshFAQ.html - with
>> my most pressing questions listed below. I hope to demonstrate mesh to a
>> group of friends at MIT this weekend. Any insights you can provide, or
>> pointers to where I can learn more, would be greatly appreciated.
>>
>> Thank you very much for your consideration,
>> Brian
>>
>> Questions
>>
>> CONFIGURATION
>>
>> What level of funcitonality is expected to work in the present code base?
>>
>> The mesh comes up with a default of Channel 1. Do I need to set my wlan0
>> to Channel 1 as well?
>>
>> What mode should mesh0 be in? Ad-hoc?
>>
>> What mode is wlan0 set to? Do I set my wlan0 device to Ad-hoc mode in
>> order to find other mesh0 devices?
>>
>> Is mesh0 considered a device or an interface? a virtual device? What is
>> the difference?
>>
>> Is wlan0 supposed to be up? or down? while the mesh is active?
>>
>> Does wlan0 have an IP address? Is it the same or different from the mesh
>> IP address?
>>
>> Does the mesh0 interface have it's own IP address assigned? Is it the same
>> aswlan0 or is it different? Can it be the same? Must it be different?
>>
>> Do we need to assign a mode to the mesh interface? Or a particular mode to
>> the associated wlan0 device? ie. must it be ad-hoc?
>>
>> PLATFORM CONSIDERATIONS
>>
>> Can I be a member of multiple meshes on one machine?
>>
>> Can mesh0 interfaces be run across USB Wireless Adapters? Is the
>> performance as good / better / worse between USB and PCI?
>>
>> Is the performance of an onboard wireless modem (e.g. in a laptop) better
>> than a PCI card or USB adapter, or the same?
>>
>> Can I run a wireless lan AND a mesh network at the same time, in parallel
>> on the same machine? (ie a normal, typical WiFi connection to an access
>> point to the internet at the same time as running a mesh0 network not
>> exposed to the internet?)
>>
>> Why is mesh supported on some Atheros and Broadcom chipsets but not
>> chipsets of other vendors? Is a mesh driver support for Ralink close? What
>> can chipset vendors do to make mesh more widely accessible? (e.g. Ralink
>> publishes driver code as open source?)
>>
>> What is the easiest way to find out if your computer can support mesh?
>
>



-- 
Javier Cardona
cozybit Inc.