Hi there,
@emilgas is correct - the DSL modems require a DSLAM at a CO (central office) to provide them a peer signal for transmission/reception.
You are looking for something like there:
http://www.adc.com/Library/Techpub/4023.pdf?refer=Library&C=DSL&L=Broadband+DSL+Access&G=Modems-Bridges-Routers-Integrated+Access+DevicesPerhaps some of these products may also be of interest to you:
http://www.shdsl.com/I am not sure whether these are still available, but they would definitely do the trick for you!
Cheers,
NotLogical