stumbled on this thread
try checking out solwise and adslnation shops, they have useful 'whitepapers' and such explaining master face plates and i-plates. Key thing is to know a) what service you have (fixed or adsl+), line attenuation (db) and noise margin/signal to noise ratio. Forums on thinkbroadband.com are very helpful. I live in the countryside (53db downstream attenuation), get 2Mbits/sec and they can stuff their broadband tax.