I have the "luxury" of two internet connections - actually two expensive and inadequately connections - that I'd like to knit together to make one expensive but adequate connection. I have (1) a satellite connection that has a relatively large bandwidth (1.5Mbps) and usage allowance (15GB/mo) but intolerable latency for some uses like VPN, SSH, remotedesktop, and surfing,
And (2) a Broadband Wireless connection, which has small latency, but a small bandwidth and usage allowance too. My downloads are too slow and too big for this connection.

I'd like to use the Broadband Wireless for VPN, SSH, remotedesktop, and surfing, but switch to the satellite connection for big file downloads (HTTP, FTP, SSH, etc), and email. I'd like it to done as automatically as possible, but could tolerate manual choices (something lie a browser menu item "Save Link as ... Using The Other Connection" or dual SSH profiles.). Can I, for example, make FTP route thru the Satellite, but SSH route through the Wireless, to the same IP address?

But I can't find anything that I can use to direct particular application connections through one particular internet connection.

Can anyone give me a clue? Or is this so obviously impossible I should not try it?

Dave

There are network managers available under both gnome and kde. They wouldn't switch it automatically for you, but it would only take a click of a button to switch your connection between two ports.