Would someone please refresh my memory. ISDN?????.
I have cable, I know dial-up and DSL but ISDN? At work I also use FF on a huge internal network. Is it ISDN???
Thanks.
ISDN was sort of a half-assed precursor to DSL. It's pretty much obsolete these days, as the form of ISDN most people would encounter is not a whole lot faster than dialup.
The warning in the article about "NOT on ISDN or dialup" isn't for any esoteric technical reasons, it's just saying not to use this tweak on a slow internet connection, because you'll choke it with too many simultaneous connections and will probably be worse off than before, performance-wise. Only use this tweak if you have any type of *fast* internet connection, like cable, DSL, T1, satellite, etc. It enables the Firefox browser to make the most of that wide-open "internet highway" you've got, instead of using just a single "lane" of the freeway at a time.