A query about the underlying technology of cable vs DSL internet (and whether I closed a door in a guy's face unnecessarily).

We're on TelstraClear's cable/inhome network in Wellington (naked broadband, using VOIP for phone services, generally very happy).

I got door-knocked at the end of last week by someone representing/trying to flog off Telecom services, particularly Telecom broadband. He got my usual response (this has happened before) of "thanks but no thanks, happy with Telstra, I think their technology is better than yours".

To my surprise, the guy started arguing pretty vehemently that the technology was actually the *same*, and that Telstra used ADSL2+, which was exactly what Telecom was offering - even going so far as to say that the modem I already had (a venerable Motorolla surfboard) was an ADSL modem. By the time I started to get a story about "my mate that used to work at Telstra", the door was closing.

I am sure there is probably scope for argument about the respective merits of cable vs DSL, and that my view that cable is better (at least in Wellington for now) may well be wrong. But I wasn't prepared for an assertion that it was both the same - I had understood that DSL and cable broadband technologies were fundamentally different. However, I don't have a clue about the actually technology and why they're different (though I can quote some acronyms I found on Google), so I then started to wonder whether he was just a bit inarticulate and that maybe the *underlying* technology or some such was the same. Professor Google seems to support my initial view that cable (or at least, HFC cable) and DSL are fundamentally different. However, most of the articles were reasonably old and focused on the States.

Is anyone able to help me shed my nagging sense of guilt?

Cheers,

[EDIT: spelling/formatting]