Did I just hear the words 'mission-critical' and 'DSL' in the same sentence? I have yet to see a DSL line, business or otherwise, that won't go down like a two-dollar whore at a moments notice.
I think you're talking about DSL service from a telco. I'm talking about point-to-point DSL. The only thing the telco does in this case is provide the copper pair for us to run our own DSL over.