It's *ALL* immensely profitable. All of the legacy DSL gear has been installed and paid for for a long time now. (so long, most of it has likely been completely depreciated.) The biggest problem I can see is one of vendor support... the vendor either doesn't support the aging gear, or they no longer exist at all. "Uverse IPDSLAM" is the technology refresh here -- which as another poster points out, is a linecard swap. This "upgrade" is a rounding error compared to the billions the idiots have wasted putting a VRAD on every street corner and front yard in the country in order to get a short enough loop. And it's ALL already obsolete; copper loop DSL is a dead end.