[znpy]

You don't of course, because you mostly can't. Yeah there might be some kind of technology to push the speed to that limit, but I don't expect to see speed pushed in the kind of areas where houses are sold basically at loss for 1€.

So, long story short: that's the advertised speed.

[pedrocr]

Advertised speed usually means it's technically possible, even if it doesn't happen in practice. It seems there is indeed 1Gb/s VSDL technology but at least Wikipedia doesn't list any such deployment in Italy. But even 100Mb/s is good enough connectivity in my experience with fiber and apparently that's common for FTTC deployments.

[icebraining]

Might not be DSL, but DOCSIS (coaxial), as part of an HFC system[1]. Version 3.1 can reach over 1Gbps, though that rather depends on how many people you are sharing it with.

[1] https://en.wikipedia.org/wiki/Hybrid_fiber-coaxial