First off, I am not a networking guy, but I have been given this problem to solve.
The problem: Our office wants to introduce another ADSL internet connection (making a total of 2). Each ADSL has a router, and the upper floor will use one connection, the other (lower floo) one will use the other for internet purposes. Now, we want to enable file sharing on the server. Since, the server is on the upper floor, and is only connected to one router connection, and the the down floor is to the other, we are on separate networks. The server is ubuntu, while the other computers on both floors are windows and macs. We need to be able store file on the server, from both the network at the upper floor (which is happenning now), and the lower floor. Is this possible, for the other network to upload files to the server? We donot want to use internet for file sharing as the speed is not good and will betray the purpose of getting another internet connection.
How should I go about getting this setup, if it is even possible?