Virtual WiFi on Linux?
greearb at candelatech.com
Wed Oct 19 12:37:08 EDT 2005
Jean Tourrilhes wrote:
> On Tue, Oct 18, 2005 at 10:00:10AM -0600, Alejandro Bonilla Beeche wrote:
>> Did you know about this? Could the wireless-tools support this or is
>>just some weird Microsoft feature?
>>UNIX is user friendly, it's just picky about who its friends are
> I was talking with some HP product people about that a couple
> of years ago (for an application they don't discuss here
> actually). Basically, you connect to multiple network at once. Of
> course, because you have only a single transmitter/receiver in your
> hardware, what you really do is time slotted hopping, you periodically
> hop between each AP.
> To implement this on Linux, the Wireless Tools would be the
> least of your problems. What you would need to do is to extend IP
> aliasing. You create multiple virtual interfaces on top of your real
> interface (wlan0:0, wlan0:1, wlan0:2). You assign each of this virtual
> interface an ESSID (using regular Wireless Tools). Somehow, you need
> to put an AP scheduler between the virtual interfaces and the real
> interface, the scheduler can control the real interface using regular
> Wireless Tools, it check how much traffic there is on each virtual
> interface to decide how long to spend with each AP. Obviously, if you
> want the performance to not suck, you need fast AP switching
> (currently available only with HostAP, doable with any card using the
> kernel ieee stack).
> That would be a nice project, however you have to ask yourself
> if it is worth the effort (the example they present are far from
> compelling). I believe they might be some interesting applications of
> that along the line of Connection Diversity, but they are a few years
> down the line.
If someone could implement the ability to make one WiFi NIC appear to
be multiple NICs, even if connected to the same AP, it would be something
that my company is interested in sponsoring.
The requirements would be something like:
* Each virtual interface is a real net-device with it's own IP, MAC and (potentially) WiFi settings.
* To the AP, it appears as if N laptops/PCs are connected to it sending & receiving pkts.
My goal is to use this for testing purposes to do AP loading and such.
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc http://www.candelatech.com
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