Multi-AP wireless load balancing.

[EricFGregory]

[insert disclaimer stating that this is theoretical / something a friend wants to know / some other bullshit]

Ok, so I have a nice pretty new FreeBSD box. I want to know this:
Using several PCI wireless cards in the machine itself; is it possible to connect that machine to multiple wireless networks which are on multiple ISPs and balance traffic load (up and down, including servers) so that the machine has a theoretical bandwidth of ~ all the connections combined?
I'm still reading through a rather large and nice manual I bought and it mentioned a lagg command, but I think that was only for use on the same switch, and over several networks, all potentially 192.168.0.x, I can see that being a pretty big problem. I was thinking DNS for combining the IP addresses on the internet side of things, so that shouldn't be hard.
I know there is some router-side stuff like port forwarding, but ignore that for now.

[Syphilis]

Might be possible if software was specifically written to take advantage of that.

[Dfg]

Try Vyatta Linux, when it comes to load balancing that PC based router does the job. A simple network diagram would be more helpful if possible.

[Trueborn]

Are there only three APs? If so, are the three APs each set to a different one of the three non-overlapping channels? One must be set to channel 1, another set to 6, and the last set to 11. If not, your wireless cards will interfere with each other on transmission and you will get either very limited network throughput or zero connectivity.

Assuming the above is workable, you'll need to set up that FreeBSD box to be a router running (for all practical purposes) RIPv2 or another load balancing capable dynamic routing protocol.

Next, you'll have to decide if you want to configure per-packet or per-destination load balancing.
- Per-packet focuses mainly on in-house congestion relief and does NOT factor in things such as upstream route congestion; it can also give you problems with UDP applications such as voice/video/games due to out-of-order packets.
- Per-destination "guarantees" delivery "in order." However, if most of the traffic is to a single destination, the other routes can be left under utilized.

I'm unfamiliar with how to configure this routing in Linux as I use Cisco almost exclusively, but these aren't proprietary routing methodologies so I'm sure it can be done.