Mesh Quest

[Javier Cardona]

Hi Brian,

Thanks for your e-mail.  Comments in line...

> CONFIGURATION
>
> What level of functionality is expected to work in the present code base?

http://o11s.org/trac/wiki/RELEASE_NOTES-0.2.1
http://o11s.org/trac/wiki/RELEASE_NOTES-0.2.0
+ mesh portal functionality (bridging two networks over a mesh)

> The mesh comes up with a default of Channel 1. Do I need to set my wlan0 to
> Channel 1 as well?

The driver only supports mode of operation at a time (see
http://www.linuxwireless.org/en/users/Documentation/modes) at a time.
In other words, if you have mesh up, you should bring wlan0 down.

> What mode should mesh0 be in? Ad-hoc?

Mesh.

> What mode is wlan0 set to? Do I set my wlan0 device to Ad-hoc mode in order
> to find other mesh0 devices?

No, bring wlan0 down.

> Is mesh0 considered a device or an interface? a virtual device? What is the
> difference?

A virtual interface.
Interface because it is the interface between the OS and the wireless
device (aka wireless card).
Virtual in the sense that there are more than one interfaces for a
given wireless card.

> Is wlan0 supposed to be up? or down? while the mesh is active?

Down.  In fact, I believe that you get an error if you create a mesh
interface while wlan0 is up.

> Does wlan0 have an IP address? Is it the same or different from the mesh IP
> address?

You should assign an IP address to the mesh interface (let's call it
mesh0, but it can have any name you choose).

> Does the mesh0 interface have it's own IP address assigned? Is it the same
> as wlan0 or is it different? Can it be the same? Must it be different?

If you need to have mesh connectivity and connect to an access point
at the same time, you need two wireless cards.

> 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?

No.

> PLATFORM CONSIDERATIONS
>
> Can I be a member of multiple meshes on one machine?

Yes, but you need a separate wireless card for each mesh.

> Can mesh0 interfaces be run across USB Wireless Adapters? Is the performance
> as good / better / worse between USB and PCI?

Probably about the same.  But we don't have hard data.

> Is the performance of an onboard wireless modem (e.g. in a laptop) better
> than a PCI card or USB adapter, or the same?

The onboard wireless modem will probably be attached to the PCI bus so
you'll get similar performance.

> 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?)

Yes, but you need to wireless cards.

> Why is mesh supported on some Atheros and Broadcom chipsets but not chipsets
> of other vendors?

Limited bandwidth and funding on our end.

> Is a mesh driver support for Ralink close?

Not that I know of.  You may want to ask that in linux-wireless

> What can chipset vendors do to make mesh more widely accessible? (e.g. Ralink
> publishes driver code as open source?)

o11s requires that the wireless cards have a thin MAC (aka soft MAC)
architecture.  That's the only requirement.
Other than that, in order to modify the driver to support mesh you
only need the card specs and time...

> What is the easiest way to find out if your computer can support mesh?

We keep a list of supported drivers here:  http://o11s.org/trac

If you do lsmod on your laptop and one of those modules shows up
(ath5k, b43, ...) shows up, mesh will work.
Then follow the instructions here: http://o11s.org/trac/wiki/HOWTO to
configure it.

Cheers,

Javier


-- 
Javier Cardona
cozybit Inc.