I have 2 line ADSL out of my office , and so I must have to control separatly them . I think that's not a good choise , and would like to know if some project of software in *nix could solve my idea .
The model is :

Internet ADSL modme| |Internet ADSL modem
| |
|=========My Server load balancing ====== |
|
|
(My Office network)
hic , the model seem not tobe as I would like to look
If someone know it , please show me

I seriously doubt you can do this. I know that a router (a good one like a Cisco router.) has a feature (cannot remember the name) that will "load balance" your two lines, but probably not in the way you expect. For any one download, you will only get the speed of the line that is currently being used. In other words, you will gain on aggregate bandwidth, but not overall speed.


Ok. I conceed you might be able to pull this off with LRP or ipchains/iptables, etc. in Linux. But I'm only referring to the aggregate capacity and not the overall line speed. And if it's really possible, I don't have a clue how to do it.

check www.lartc.org you'll need to patch your kernel to achieve load distribution.
and join their mailing list - you'll get good help from gurus in the list.