|Make sure your router supports link load balancing - as this is not 'regular' load balancing (it's reverse-load balancing, or bandwidth aggregation). |
I've made a setup like this before w/ 3 DSL lines, aggregated on a freebsd router I put together.
I dunno about that specific load balancer, an old Alteon could do this no problem. The one I built used the built in IPFW firewall w/ sourcing routing to handle the differnet links.
As you ask '2 x 2= 4Mb/s?' generally not for one host - you generally set this up w/ one host going out one line, so 1 computer would still only get 2mb. Trying to distribute bandwidth more evenly than this it becomes difficult to maintain state -- I could never get per/connection distribution to work right in my freebsd setup.
But, remember this will not be one circut - so you could never pull 4mb's on ONE download - as one tcp session can only use one link at a time, but you could pull 4mb from two different sites, etc.
This also depends on your distribution method - i.e., how do the connections get distributed for the two lines? (Random, round robin) ?? The best method is of course using a 'bandwidth metric' - where the next line to use is determined by which one hast he least amount of traffic going through it -- you don't normally find this option on cheap load balancers.
I dunno about that LB you mention, but do know that a cheap-load balancer will probably not distribute the traffic correctly& you need to know what you're looking for. Personally, I would build it myself.
I've seen someone do this w/ a windows box too - though I have no idea how...
a cheapo box w/ 2 nic's running freebsd/linux can do this too, and it'll help you understand more what you're doing.
There's also some company out there that builds routers specifically designed to aggregate DSL lines like this -- I can't remember the name...I'll post it if I do.
Anyway, good luck w/ this